DSH4xxx --- Graph statements and expressions

The block between the generated markers is written by .skill/gen-diagnostics.ps1. Everything below a marker is written by hand and survives a regeneration.

DSH4200

Severity error

Message

'{0}' is not declared; did you mean '{1}'? Names are case-sensitive.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:757, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:768

Cause. An identifier does not name a local, a parameter or a file-scope declaration that is visible here. In 2.0 names are case-sensitive (1.x was not), so intensity and Intensity are two different names; when the only difference is case the message says so and names the declaration it found.

Fix. Correct the spelling, or declare the name above the line that uses it. A name that comes from a header only exists below the #include that pulled the header in: an #include written at the bottom of the file declares nothing for the code above it.

DSH4201

Severity error

Message

'{0}' is not a type; did you mean '{1}'? Type names are case-sensitive.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinder.cpp:560, Source/DreamShaderLang/Private/Semantic/LangBinder.cpp:571, Source/DreamShaderLang/Private/Semantic/LangBinder.cpp:585, Source/DreamShaderLang/Private/Semantic/LangBinder.cpp:707, Source/DreamShaderLang/Private/Semantic/LangBinder.cpp:980, Source/DreamShaderLang/Private/Semantic/LangBinderStatements.cpp:544

Cause. A type spelling is neither a builtin (float3, Texture2D, material, Substrate, …) nor a struct declared before this line. Also raised for void where a value type is required — a field, a parameter or a variable.

Fix. Check the spelling and its case; move the struct above its first use; for a type that comes from a header, check that the header is included above this line.

DSH4202

Severity error

Message

A string has no value in an expression; it is only ever the value of a reflected property, as in 'UE.Expression(Class = "...")'.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:625

Cause. A quoted string reached an expression. The language has no string values: a string is only ever the value of a reflected literal property, as in UE.Expression(Class = "…") or Desc = "…".

Fix. Remove the string, or move it to the property argument it was meant for.

DSH4203

Severity error

Message

'{0}' is a namespace, not a value; write '{0}.SomeNode(...)'.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:717

Cause. UE or Substrate was used as if it were a variable. They are namespaces; the only thing that follows them is a node name and a call.

Fix. Write UE.TexCoord(0) rather than UE. If a variable of that name was intended, declare it — a declared UE wins over the namespace, and the reflected call is then what stops working.

DSH4204

Severity error

Message

'{0}' is a type, not a value; write '{0}(...)' to construct one.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:512

Cause. A type name appears where a value is expected: float3;, x = float3, f(float3).

Fix. Construct the value — float3(0.0) — or write a cast, (float3)x.

DSH4205

Severity error

Message

'{0}' has no field called '{1}'.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:1125

Cause. A struct value was asked for a field it does not have. The message names the struct and suggests a field that differs only in case, when there is one.

Fix. Correct the field name, or add the field to the struct. Fields are case-sensitive.

DSH4206

Severity error

Message

'{0}' on a texture is a call: write 'Tex.{0}(UV)'.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:1264

Cause. Tex.Sample (or Tex.SampleLevel) appears without its argument list. A texture's methods are calls; there is no value to take from the method itself.

Fix. Write Tex.Sample(UV), Tex.Sample(TexSampler, UV) or Tex.SampleLevel(UV, Level).

DSH4207

Severity error

Message

A value of type {0} has no member '{1}'.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:1274

Cause. A member access was written on a value whose type has no members of that kind: a swizzle on a texture, a field on a number, an attribute on something that is not a material.

Fix. Check the type the expression actually has — the message names it. Note that .rgb is only valid on a numeric value of at least three components, and m.BaseColor only on a material.

DSH4208

Severity error

Message

A value of type {0} has no method '{1}'.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:2985, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:3103, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:3118, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:4909

Cause. A call was written on something that is not callable: a name that is not a function, a builtin, a struct or UE./Substrate. followed by a node; or a method a texture does not have. A case-only difference from a declared name is named in the message.

Fix. Correct the spelling (names are case-sensitive), declare the function above the call, or reach an engine node through UE.Expression(Class = "…").

DSH4210

Severity error

Message

'{0}' is already declared in this file; one name declares one thing.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinder.cpp:482, Source/DreamShaderLang/Private/Semantic/LangBinder.cpp:492, Source/DreamShaderLang/Private/Semantic/LangBinderPipeline.cpp:861

Cause. One name is declared twice. Structs, file-scope variables and functions share one namespace, because a struct's constructor and a function call are spelled the same way. When the two declarations are in different files the message names both — the usual cause is a header declaring a name the file also declares, or two headers declaring it.

In a .dsp it is also raised for two uniforms whose names differ only in case (The parameter 'radius' differs from 'Radius', declared on line 3, in case only; ...): the pipeline asset keeps parameter names as Unreal names, which compare ignoring case, so the two would be one parameter there. A static const is folded away and never reaches the asset, so it is not compared this way.

Fix. Rename one of them. There is no overloading: two functions of one name are this error even when their parameter lists differ.

DSH4211

Severity error

Message

Including '{0}' from '{1}' closes a cycle; a header may not include itself, directly or through another header.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinder.cpp:445

Cause. Following an #include / import leads back to a file already being read. The message names the file that closes the loop and the file that included it.

Fix. Break the cycle. A shared type or constant that two headers both need belongs in a third header both of them include; DreamShaderLang has no include guards to make a cycle harmless.

DSH4212

Severity error

Message

'{0}' cannot be read: this front end was started without an include resolver, so nothing a header declares is visible.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinder.cpp:409

Cause. The file has an #include / import and this front end was started without an include resolver, so nothing a header declares is visible. Inside a compile this cannot happen; it means a tool called BindDreamShaderLang with FBindOptions::IncludeResolver left empty.

Fix. In a tool, supply the resolver. If the intent was to bind one file in isolation, expect every name the header would have declared to be DSH4200 as well.

DSH4213

Severity error

Message

'{0}' is declared twice in struct '{1}'.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinder.cpp:688

Cause. A struct declares two fields with the same name.

Fix. Rename one. Field names are case-sensitive, so Colour and colour are not this error.

DSH4214

Severity error

Message

'{0}' is declared twice in the parameter list of '{1}'.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinder.cpp:957

Cause. A parameter list declares one name twice.

Fix. Rename one of them.

DSH4215

Severity error

Message

The '{0}' argument of '{1}' is given twice.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:3461, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:3791, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:4458, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:4537, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:4575, Source/DreamShaderLang/Private/Semantic/LangBinderSubstrate.cpp:697

Cause. One argument slot is filled twice in a call: the same parameter named twice, a named argument that repeats what a positional argument already filled, or a pin and its literal twin both given.

Fix. Delete the duplicate. Positional arguments fill the parameters in order, so the first named argument that names one of those parameters is the duplicate.

DSH4216

Severity error

Message

'{0}' takes its arguments in order and has no argument called '{1}'.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:3426, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:3769

Cause. A named argument names nothing in the callee: no parameter of that function, or no pin of that builtin. The message lists the builtin's argument names, and suggests a case-only match for a function's parameters.

Fix. Correct the name, or pass the argument positionally.

DSH4217

Severity error

Message

'{0}' is missing its '{1}' argument.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:3489, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:3843

Cause. A call leaves a parameter with no argument and no default, or a builtin without one of its arguments.

Fix. Pass it, or give the parameter a default in its declaration — a default makes an exported function's input optional.

DSH4218

Severity error

Message

'{0}' writes back {1}, and this variable is {2}; an out argument has to match exactly.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:3904, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:3949

Cause. An argument passed to an out / inout parameter is a variable of a different type. Unlike an input, an out argument is written back into, and a conversion has nowhere to live on the way out.

Fix. Declare the variable with the parameter's exact type, then convert after the call.

DSH4220

Severity error

Message

'{0}' is already declared in this block.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderStatements.cpp:149, Source/DreamShaderLang/Private/Semantic/LangBinderStatements.cpp:159, Source/DreamShaderLang/Private/Semantic/LangBinderStatements.cpp:169

Cause. A local variable redeclares a name in the same block, or hides one from an enclosing block or a parameter. HLSL allows the hiding; this language does not, because in a graph the two variables become two unrelated nodes with one name and every node description downstream is then wrong about which one it is.

Fix. Give one of them another name. Two variables of the same name in sibling blocks are fine — they are not visible to each other and each gets its own slot.

DSH4221

Severity error

Message

{0}() has no components; write the value, as in 'float3(0.0)'.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:3176

Cause. A constructor was written with no arguments: float3().

Fix. Write the value: float3(0.0) broadcasts, float3(x, y, z) builds one component at a time.

DSH4222

Severity error

Message

'{0}' has {1} fields and this list has {2}.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:2704, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:2809, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:2842, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:3242, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:3314

Cause. The pieces do not add up: a constructor whose arguments' components do not total the target's, an initializer list of the wrong length, or a struct constructed with the wrong number of fields.

Fix. Count the components. float4(v3, w) is 3 + 1; float3(v4) is 4 into 3 and is refused — write v4.xyz. The one exception is a single scalar, which broadcasts to any width.

DSH4223

Severity error

Message

{0} expects {1}, and this is {2}.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:1917, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:2603, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:2615, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:2630, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:3155

Cause. A cast the graph cannot carry: to or from a type that is not a number or a bool, or a cast that drops components ((float3)v4).

Fix. For a narrowing cast, write the swizzle that says which components were meant — .xyz. For a texture, a sampler, a material or a Substrate value there is no cast at all.

DSH4224

Severity error

Message

'{0}' takes at most {1} arguments.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:3447, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:3507, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:3717, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:4953, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:5020

Cause. A call has more or fewer arguments than the callee takes. For a texture sample the message gives the exact spellings, because the sampler argument is optional and the arity depends on whether it was written.

Fix. Match the declaration. A parameter with a default may be omitted; one without may not.

DSH4225

Severity error

Message

A constructor takes its components in order; named arguments belong on 'UE.' nodes and on function calls.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:3167, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:4921

Cause. Named arguments were used where only positional ones are taken: a constructor, a texture sample.

Fix. Drop the names. Named arguments belong on UE./Substrate. nodes, where they match a pin or a property, and on calls to declared functions, where they match a parameter.

DSH4226

Severity error

Message

{0} expects {1}, and this is {2}.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:1951, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:1999, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:2542, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:3210, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:3222

Cause. An operand does not fit where it is used. The two common shapes are a width that does not match (float3 * float2 — a vector never widens silently) and a type that is not a number at all (a texture, a material, a struct in arithmetic).

Fix. Make the widths agree with a swizzle or a constructor. A scalar broadcasts to any width, so v3 * 2.0 is fine and v3 * v2 is not.

DSH4227

Severity error

Message

'{0}' is not an operation this language spells as a call.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:2103, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:2219, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:2262, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:2299, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:2458

Cause. An operator with no graph form: &, |, ^, <<, >>, ~ and their assignment forms. The graph carries floats, not bit patterns.

Fix. Express it in arithmetic, or move the code into a /// @custom function, whose body is HLSL the shader compiler sees whole.

DSH4228

Severity error

Message

{0} expects {1}, and this is {2}.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:1906

Cause. A value does not fit where it is being stored: the right of an =, an initializer, a parameter default or a return. The message names both types.

Fix. As DSH4226 — adjust the width with a swizzle or a constructor. An int used where a float is expected converts silently and is never this error.

DSH4229

Severity error

Message

A 'uniform' is an input and a 'static const' is a constant; neither can be assigned to. Copy it into a local first.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:2392, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:2433, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:2441

Cause. The left side of an assignment cannot be assigned to. Three messages: it is a uniform (an input) or a static const (a constant); it is one component of a member of a Substrate value being built (S.DiffuseAlbedo.r = 1;) -- such a member is a pin, and a pin is connected whole; or it is no variable, struct field, material pin or swizzle of one at all (a call, a literal, an arithmetic result).

Fix. Copy a uniform into a local before changing it. For a Substrate value, build the vector first and assign the whole member. Otherwise assign to a named variable.

DSH4230

Severity error

Message

'.{0}' is not a swizzle; a swizzle is one to four of 'xyzw' or 'rgba'.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:1291, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:1310, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:1326, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:1346, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:1713, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:2409

Cause. One of five things:

• a letter that is not one of xyzw / rgba,
• more than four components,
• a component past the end of the value (.w on a float3, v[3] on a float2),
• the two families mixed in one mask (.xg),
• a repeated component in an assignment target (v.xx = f).

Reading a repeated component is fine: v.xxx is HLSL replication and binds like any other mask. Writing one is not — the two writes land on the same component with no order between them, so the result would depend on how the graph happened to be built.

Fix. Use one family and stay in range. For an assignment, write each component on its own line.

DSH4231

Severity error

Message

'{0}.{1}' is an output node, not a value: write it as a statement on a line of its own.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:4802

Cause. A node with no value was used as one. Custom-output classes (ClearCoatBottomNormal, ThinTranslucentMaterialOutput, the volumetric-advanced outputs…) write into the material rather than producing something to read, and a class with no output pins is the same case.

Fix. Write the call as a statement on a line of its own.

DSH4233

Severity error

Message

A component index must be a compile-time constant; write a swizzle such as '.z', or select with 'lerp'.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:1704

Cause. v[i] with an index the binder cannot evaluate. A component index becomes a swizzle, and a swizzle is fixed when the graph is built.

Fix. Write the swizzle (v.z), or select between components with lerp / ?:.

DSH4234

Severity error

Message

A value of type {0} cannot be indexed.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:1740

Cause. [...] was written on a value that is neither an array, a vector nor a matrix.

Fix. Check the type — the message names it.

DSH4235

Severity error

Message

'++' and '--' write back into what they read, so they need a variable.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:2233

Cause. ++ or -- was applied to something that is not a variable. They read and write back, so they need somewhere to write.

Fix. Apply them to a local, an out/inout parameter, a struct field or a material pin.

DSH4236

Severity error

Message

An 'in' parameter is a function input pin and cannot be written to; declare it 'out' or 'inout', or copy it into a local.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:2400

Cause. An in parameter was assigned to. In a graph an input parameter is a function input pin, and a pin cannot be written.

Fix. Declare it out or inout if the caller should see the change; otherwise copy it into a local and modify that.

DSH4237

Severity error

Message

An initializer list only has a meaning against a declared type; it cannot stand on its own.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:2681, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:2748, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:2832

Cause. An initializer list appears where nothing says what it should become — or a target that cannot be written as a list (a texture, a material), or an array initialised with something that is not a list.

Fix. Give it a declared type: float4 v = { 1, 0, 0, 1 };. An array is initialised with = { … } and nothing else.

DSH4238

Severity error

Message

'{0}' returns nothing, so its call has no value; its results come back through its out parameters.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:3978

Cause. A call to a function that returns void was used as a value.

Fix. Call it as a statement. A function with several results returns them through out parameters, which the caller declares as variables and reads after the call.

DSH4239

Severity error

Message

'{0}' is an out parameter of '{1}', so its argument has to be a variable.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:3875, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:3931

Cause. The argument passed to an out / inout parameter is not a variable, so there is nowhere to write the result.

Fix. Declare a local of the parameter's type and pass that.

DSH4240

Severity error

Message

'#pragma endregion' closes a box that was never opened.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderDirectives.cpp:869, Source/DreamShaderLang/Private/Semantic/LangBinderDirectives.cpp:888, Source/DreamShaderLang/Private/Semantic/LangBinderDirectives.cpp:896

Cause. #pragma region and #pragma endregion do not pair up — an endregion with nothing open, or a region never closed. Regions nest, and they are counted per file and per function body, so a region opened in a header cannot be closed by the file that included it.

Fix. Add the missing line. A region opened inside a function body is closed inside that body.

DSH4241

Severity error

Message

A multi-dimensional array has no graph form; declare one dimension, or move the code into a '/// @custom' function.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinder.cpp:607

Cause. A declaration has more than one [n]. The graph has no arrays at all; the one dimension that is supported exists only so a static const table can be indexed at compile time.

Fix. Flatten it to one dimension, or move the code into a /// @custom function.

DSH4242

Severity error

Message

An array index must be a compile-time constant: the graph has no arrays, so every element is read at compile time.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:1639, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:1648, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:1676

Cause. An array element could not be resolved at compile time: a non-constant index, an index out of range, or an array whose initializer is not constant. There are no arrays in a graph, so every element read has to fold to a value while compiling.

Fix. Declare the array static const with a constant initializer and index it with a literal or a static const. For a table that has to be read at run time, use a texture or a @custom function.

DSH4243

Severity error

Message

Both sides of this '/' are integers, and the material graph has no integer division; write 'float(a) / b' for the fraction, or 'floor(float(a) / b)' for the whole part.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:2052

Cause. Both operands of a / are integers. HLSL would divide them as integers and drop the fraction; a material graph has no integer division at all -- every value in it is a float -- so the two would disagree, and the compiler does not pick one silently. In a 1.x Graph only a division of two integer constructor calls (int(7) / int(2)) is refused, as 1.x refused it (DSH4063); 1.x typed every number literal float, so 7 / 2 there is 3.5 (legacy rule L27; 2.0.0 – 2.1.0 refused it).

Fix. Say which one is meant: float(a) / b for the fraction, floor(float(a) / b) for the whole part.

DSH4244

Severity error

Message

A matrix row cannot be read: the graph has no matrices. Move the code into a '/// @custom' function, where the matrix is an input.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:1691

Cause. A row of a matrix was read (M[1]). A matrix has no graph value; it exists only as a /// @custom input or output, or as a constant that folds away entirely.

Fix. Move the code into a /// @custom function, where the matrix is an ordinary HLSL value.

DSH4245

Severity error

Message

An unsized array needs an initializer list to take its length from.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinder.cpp:626, Source/DreamShaderLang/Private/Semantic/LangBinder.cpp:649, Source/DreamShaderLang/Private/Semantic/LangBinder.cpp:659

Cause. An array size is not an integer literal between 1 and 4096, or an unsized [] has no initializer list to take its length from. The size is read before anything is bound, so an expression — even a constant one — cannot be used.

Fix. Write a literal, or [] with an initializer list.

DSH4246

Severity error

Message

The material graph has no hyperbolic node, so '{0}' cannot be lowered; write it in a '/// @custom' body, where the shader compiler has it.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:3366

Cause. sinh, cosh or tanh was called. The core table carries all three so a /// @custom body and the type checker agree about them, but the material graph has no hyperbolic node and the emitter does not synthesise one out of exp — a chain that looked right would quietly differ from the shader compiler's own implementation.

Fix. Move the expression into a /// @custom function, whose body is HLSL the shader compiler sees whole and where all three exist. If only one value is needed, writing the identity out in terms of exp explicitly is also fine — the point is that the file, not the emitter, says so.

DSH4250

Severity error

Message

'{0}' is the GLSL spelling; this language is HLSL, so write '{1}'.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:3034

Cause. A GLSL spelling was used: mix, fract, mod. 1.x silently rewrote these to their HLSL equivalents; 2.0 does not, because a silent rewrite of one identifier into another is the class of mistake this front end exists to stop.

Fix. Write the HLSL name the message gives: lerp, frac, fmod.

DSH4251

Severity warning

Message

'{0}' hides the file-scope declaration of the same name for the rest of this function.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderStatements.cpp:181

Cause. A local variable has the same name as a file-scope declaration, usually one that came from a header. This is allowed — a file cannot be expected to know every name its headers declare — but from that point on the uniform or constant of that name is unreachable in this function.

Fix. Rename the local if the file-scope one was meant. Otherwise ignore it, or rename to make the intent obvious to the next reader.

DSH4260

Severity error

Message

{0} expects {1}, and this is {2}.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:1928, Source/DreamShaderLang/Private/Semantic/LangBinderExpressions.cpp:2511, Source/DreamShaderLang/Private/Semantic/LangBinderStatements.cpp:628

Cause. The condition of an if, a for, a while, a do or a ?: is not a single true-or-false value: a vector (if (v3 < 1.0)), a texture, a material, a struct.

Fix. Reduce it to one value: compare one component, or use all() / any() semantics written out by hand. A number is accepted and means "not zero".

DSH4261

Severity error

Message

'{0}' returns {1}, so this 'return' needs a value.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderStatements.cpp:735

Cause. A bare return; in a function that declares a return type.

Fix. Return a value, or declare the function void and hand its results back through out parameters.

DSH4262

Severity error

Message

'{0}' returns nothing, so this 'return' cannot carry a value; extra results are written to 'out' parameters.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderStatements.cpp:751

Cause. return <value>; in a void function.

Fix. Drop the value, or give the function a return type.

DSH4263

Severity error

Message

'discard' belongs in a material entry or a layer; a material function has no pixel of its own to drop. Write the mask into 'm.OpacityMask' instead.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderStatements.cpp:493

Cause. discard in a function that is not the material entry, a @layer or a @layerblend. A material function is a subgraph of whatever calls it; it has no pixel of its own to throw away.

Fix. Write the mask into m.OpacityMask and let the material discard, or move the discard into the entry.

DSH4264

Severity error

Message

'break' leaves a loop, and this one is not inside a 'for', 'while' or 'do'.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderStatements.cpp:472

Cause. break or continue outside any loop.

Fix. Delete it, or put it inside the loop it belongs to. Note that this language has no switch, so break only ever belongs to a loop.

DSH4300

Severity error

Message

Node {0} reads {1} from node %{2}, which does not exist; the graph has {3} nodes.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:221

Cause. A node's operand or named input refers to node %N, and the graph has no node with that index. The IR addresses values by position in FIRGraph::Nodes, so this means a builder or a pass produced an index against a different (or an older) graph — most often a pass that removed nodes without repointing the users, or a value carried across two products.

Fix. Compiler side: check the last pass that ran. RunDreamShaderIRPasses prune and dedupe are the two that renumber; both must repoint every user before a node disappears. Author side: nothing you wrote causes this; report the file.

DSH4301

Severity error

Message

Node {0} reads {1} from node {2}, which is a statement and produces no value.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:240, Source/DreamShaderLang/Private/IR/IRValidator.cpp:253

Cause. Two shapes. Either a node reads output k of a node that has fewer than k+1 outputs — multi-output nodes (TextureSample, Reflected on a class with several outputs, Custom with additional outputs, GetMaterialAttributes) are the only ones with an output other than 0, so this is usually a member access that resolved to the wrong output index — or a node reads a statement, which produces no value at all. A statement is the material sink, a function output, or a reflected custom-output class such as UE.VolumetricAdvancedMaterialOutput (FIRNode::IsStatement()).

Fix. Author side: a custom-output node is a statement, not a value — write UE.ClearCoatNormalCustomOutput(Input = n); on its own line rather than assigning it to something. The binder reports that spelling as DSH4231, so seeing it here means the node was built anyway. Compiler side: compare FBoundExpr::FieldIndex for the NodeOutput access with the Outputs the builder gave the node; the catalog entry's Outputs array is the authority for a reflected class.

DSH4302

Severity error

Message

Node {0} has {1} operand(s); this op takes exactly {2}.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:382, Source/DreamShaderLang/Private/IR/IRValidator.cpp:393

Cause. The node has more or fewer operands than its op accepts. The arity comes from GetCoreOpInfo, the one table that has it, so a mismatch means the builder assembled the node by hand rather than from that table.

Fix. Compiler side: build core nodes from FIRCoreOpInfo::MinArity/MaxArity instead of literal counts. Author side: report the file, with the expression the diagnostic points at.

DSH4303

Severity error

Message

Node {0} has nothing connected to {1}; every operand of this op must carry a value.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:209

Cause. An operand slot that must carry a value is empty. Only two slots in the whole IR may be left unset: Compare's operand 3 (the engine If node's optional AEqualsB pin) and TextureSample's operands 2 and 3 (the optional sampler and mip value). Everything else is a hole the emitter cannot fill.

Fix. Compiler side: an expression lowered to FIRValue::None() without a diagnostic — look for a lowering path that returns early on an error it did not report. Author side: report the file.

DSH4304

Severity error

Message

Node {0} carries {1} positional operand(s); this op takes {2}.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:347, Source/DreamShaderLang/Private/IR/IRValidator.cpp:364

Cause. The node uses the wrong connection style for its op. IR.h fixes this per op: the core math ops, Swizzle, Append, Select, Compare, StaticSwitch, TextureSample, FunctionOutput, Convert and Broadcast take positional operands; Reflected, FunctionCall, Custom, the three material-attribute ops and MaterialSink take named inputs; the four leaves (Constant, Parameter, TextureParameter, FunctionInput) take neither.

Fix. Compiler side: a node built with Operands where the emitter will look in Inputs (or the reverse) silently emits an engine node with nothing connected, which is why this is checked rather than tolerated. Author side: report the file.

DSH4305

Severity error

Message

Node {0} has a named input with no pin name.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:948, Source/DreamShaderLang/Private/IR/IRValidator.cpp:961

Cause. A named input has an empty pin name, or the same pin name appears twice on one node. An engine FExpressionInput takes exactly one connection, so a second binding to the same pin would mean one of the two values is dropped without a word.

Fix. Compiler side: this is usually an argument matched twice — once positionally through PositionalParameters and once by name. FBoundArgument::Target is the deduplication point. Author side: check whether you passed the same argument both positionally and by name in a UE.* call; if you did not, report the file.

DSH4306

Severity error

Message

Node {0} does arithmetic on operand {1}, which is a {2}; the graph carries only float1 to float4, so a matrix, a texture or a material cannot reach a math node.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:690, Source/DreamShaderLang/Private/IR/IRValidator.cpp:704

Cause. A math node reads or produces a value the material graph has no wire for. The graph carries float1 to float4 and nothing else: a matrix, a texture object, a sampler, a material and a Substrate value all answer 0 to FIRType::GraphComponentCount().

Fix. Author side: this is the IR-level echo of DSH4361 — a matrix reached arithmetic. Move the expression into a /// @custom function, whose body is verbatim HLSL and may use matrices freely. Compiler side: the binder should have refused this before lowering; if it did not, the type it assigned to the operand is wrong.

DSH4307

Severity error

Message

Node {0} is a statement and must have no outputs, but it declares {1}.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:289, Source/DreamShaderLang/Private/IR/IRValidator.cpp:300

Cause. Either a value node declares no outputs — nothing can read it, so it cannot have been built for a reason — or a statement node declares some.

A statement is MaterialSink, FunctionOutput, or a Reflected node with zero outputs, which is how a custom-output class (UE.VolumetricAdvancedMaterialOutput, UE.ClearCoatNormalCustomOutput) is modelled. That third shape is a legal root and is not reported here; the test is FIRNode::IsStatement(), never an op list.

Fix. Compiler side: every builder path that adds a node must fill Outputs before returning the value; a node added and typed later is the usual source. Author side: report the file.

DSH4308

Severity error

Message

Node {0} has {1} output name(s) for {2} output(s); the two lists are either parallel or the names are omitted.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:311, Source/DreamShaderLang/Private/IR/IRValidator.cpp:331

Cause. OutputNames exists to name multi-output nodes, and it is either empty (the node's outputs are positional) or exactly as long as Outputs. A short list means the emitter would read past its end; two outputs with the same name mean a member access could not pick between them.

Fix. Compiler side: fill both lists in the same place. For a reflected node, copy the catalog entry's Outputs names verbatim. Author side: report the file.

DSH4309

Severity error

Message

Node {0} is a reflected node with catalog index {1}, which is not an entry of the builtin catalog.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:1038, Source/DreamShaderLang/Private/IR/IRValidator.cpp:721

Cause. Two shapes of the same mistake. Either a Reflected node's CatalogIndex does not point at an entry of the builtin catalog — so the emitter cannot know which class to create — or a node that is not reflected carries a catalog index, which would send the emitter down the reflection path for a Multiply.

Fix. Compiler side: CatalogIndex is set only where a Reflected node is built, from the FBoundExpr::Index the binder recorded. A stale index usually means a node was copied and its op changed. Author side: if the catalog was loaded from an exported manifest, re-export it — the index is positional and an older manifest does not match a newer engine.

DSH4310

Severity error

Message

Node {0} connects pin '{1}', which '{2}' does not have.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:758

Cause. A reflected node connects a pin the class does not have. The catalog's Inputs list is built from the class's FExpressionInput members, so a pin that is not in it does not exist on that engine class.

Fix. Author side: check the spelling — pin matching is case-sensitive, and the name is the C++ member name (Coordinates, not UVs, on a TextureSample; VectorInput on a Normalize). The material editor's node tooltip shows the pin names. Compiler side: if the pin is real, the reflection exporter skipped it — check IsMaterialExpressionInputProperty.

DSH4311

Severity error

Message

Node {0} sets property '{1}', which '{2}' does not have.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:800

Cause. A reflected node sets a property the class does not have. ClassSpecifier (the IR's own record of what the author wrote) and a pin's Const* twin are accepted; everything else must be a reflected property of the class.

Fix. Author side: an unknown Key = value in a UE.* call, usually a typo or a property that exists on a different expression class. Compiler side: if the property is real but not in the catalog, the reflection exporter filtered it — check the property-flag test in BuildBuiltinCatalogFromReflection.

DSH4312

Severity error

Message

Node {0} names class '{1}' but its catalog entry is '{2}'; the two must agree.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:735

Cause. The node's ClassName and the catalog entry its CatalogIndex points at name two different classes. The emitter uses one of the two and the validator refuses to guess which.

Fix. Compiler side: set ClassName from Catalog.Expressions[CatalogIndex].ShortName at the point the node is built, never from the source text; the author's spelling belongs in Prop::ClassSpecifier. Author side: re-export the catalog manifest if you are using one.

DSH4313

Severity error

Message

Material product {0} has {1} MaterialSink node(s); a material has exactly one.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:1072, Source/DreamShaderLang/Private/IR/IRValidator.cpp:1082, Source/DreamShaderLang/Private/IR/IRValidator.cpp:1096, Source/DreamShaderLang/Private/IR/IRValidator.cpp:1107

Cause. The product's sink does not match its kind. A Material product has exactly one MaterialSink node and FIRGraph::Sink points at it; a MaterialFunction, MaterialLayer or MaterialLayerBlend has none and Sink is INDEX_NONE.

Fix. Compiler side: the sink is created once, at the end of the Entry, from the material field map — two sinks mean the entry was lowered twice. Author side: a file with two export void M(inout material) entries is DSH6200 and should have been refused earlier; report the file.

DSH4314

Severity error

Message

Product {0} lists node %{1} in its {2}, and that node does not exist.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:1125, Source/DreamShaderLang/Private/IR/IRValidator.cpp:1137, Source/DreamShaderLang/Private/IR/IRValidator.cpp:1158, Source/DreamShaderLang/Private/IR/IRValidator.cpp:1168, Source/DreamShaderLang/Private/IR/IRValidator.cpp:1182

Cause. The graph's FunctionInputs / FunctionOutputs lists and the FunctionInput / FunctionOutput nodes in it disagree: a listed index does not exist, a listed node is of the wrong op, a node of the right op is not listed, or a Material product declares a signature at all. The lists are what give the asset's inputs and outputs their order (their dense SortPriority), so a node missing from them would end up unordered.

Fix. Compiler side: append to the list in the same statement that adds the node. Author side: report the file.

DSH4315

Severity error

Message

Product {0} is a {1} and produces nothing; a material function needs at least one FunctionOutput.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:1192

Cause. A material function, layer or layer blend has no FunctionOutput node, so the asset would have nothing to connect to. An exported function contributes an output for its return value (named Result) and one per out parameter; a function with neither produces no asset.

Fix. Author side: give the exported function a non-void return type or an out parameter. A @layer function's output is its inout material parameter, so check that the parameter is actually spelled inout. Compiler side: check FBoundFunction::MaterialResultParam.

DSH4316

Severity error

Message

Product {0} cannot be ordered: these nodes feed themselves, directly or through others -- {1}.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:1516

Cause. The graph cannot be put in an order where every operand precedes its user, which means some node feeds itself, directly or through a chain. A material graph is a DAG; the emitter walks TopologicalOrder() and would otherwise write a node before the node it reads.

Fix. Compiler side: the usual source is a pass that repointed a user onto a node downstream of it — the dedupe pass merging two nodes where one is an ancestor of the other. The diagnostic lists the nodes it could not order; the cycle is among them. Author side: report the file with the function the nodes come from.

DSH4317

Severity error

Message

Node {0} needs a string Mask property holding the component letters.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:512, Source/DreamShaderLang/Private/IR/IRValidator.cpp:524, Source/DreamShaderLang/Private/IR/IRValidator.cpp:554, Source/DreamShaderLang/Private/IR/IRValidator.cpp:567, Source/DreamShaderLang/Private/IR/IRValidator.cpp:585

Cause. A Swizzle node's mask is missing, is not a string, is empty, is longer than four characters, contains something other than x, y, z and w, names the same component twice, or is not in strictly ascending order (xz is a mask; zx is not). The canonical mask is lower-case xyzw; rgba is rewritten to it at bind time, so anything else reaching the IR is a builder mistake.

The ordering rule is not fussiness: a ComponentMask carries four independent R/G/B/A flags and has no way to express order or repetition at all, so .yx emitted as one node would silently come out as .xy.

Fix. Compiler side: FBoundExpr::Swizzle already holds the canonical mask — copy it rather than re-deriving it from the source text. A reordering or repeating swizzle lowers to per-channel masks plus an AppendVector, which is what 1.x emitted: the builder splits it, and only the ascending remainder becomes a Swizzle node. Author side: .yx and .xxz are legal source, so seeing this means the split did not happen — report the file.

DSH4318

Severity error

Message

Node {0} masks '{1}' out of a {2}, which has only {3} component(s).

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:615

Cause. The mask names a component the operand does not have — .w on a float3, .z on a float2. In HLSL that is an error; in a graph it would silently read a channel the wire does not carry.

Fix. Author side: widen the value (float4(v, 1)) or shorten the mask. Compiler side: the binder raises DSH4230 for this at source level; reaching the IR means the operand's type changed between binding and lowering — usually a conversion inserted on the wrong side.

DSH4319

Severity error

Message

Node {0} switches on a {1}; a StaticSwitch condition is a single static bool.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:648, Source/DreamShaderLang/Private/IR/IRValidator.cpp:661

Cause. A branch node's condition has the wrong type. A StaticSwitch condition must be a single static bool — a StaticBoolParameter, or !, &&, || over static bools. A Select condition must be one component, the 0/1 value the lowered If compares against 0.5.

Fix. Compiler side: if the condition is a wide vector, a comparison was lowered without collapsing to a scalar. If a StaticSwitch has a non-bool condition, the decision between static and dynamic lowering was made on a value the binder did not mark static. Author side: a #pragma-level static switch needs a uniform bool with /// @static; without it the branch is dynamic, which is also fine.

DSH4320

Severity error

Message

Node {0} sits in region {1}, which does not exist; the graph has {2} region(s).

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:1211, Source/DreamShaderLang/Private/IR/IRValidator.cpp:1228, Source/DreamShaderLang/Private/IR/IRValidator.cpp:408

Cause. A region reference does not resolve: a node sits in a region index the graph does not have, a region names a parent that does not exist, or the parent chain loops back on itself. Regions come from #pragma region / #pragma endregion and nest strictly.

Fix. Compiler side: FBoundModule::Regions is copied into the graph wholesale, so the indices must be copied with it — a graph that keeps its own region list must remap FIRNode::Region. Author side: unbalanced #pragma region is DSH4240 and is reported at source level; report the file if you see this one instead.

DSH4321

Severity error

Message

Product {0} has dedupe keys on {1} of its {2} nodes; the key is either computed for the whole graph or for none of it.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:1537

Cause. Some nodes of a graph have a DedupeKey and others do not. The key is structural: it is computed for the whole graph in one pass or for none of it, because a key built from an operand that has no key of its own is not structural at all.

Fix. Compiler side: compute keys in TopologicalOrder() so every operand already has one, and add nodes created after the dedupe pass with an empty key only if the whole pass is re-run. Author side: report the file.

DSH4322

Severity error

Message

Nodes %{0} and %{1} of product {2} have the same dedupe key, so the dedupe pass should have merged them into one.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:1586

Cause. Two nodes of one graph have the same dedupe key, so they describe the same expression and the dedupe pass should have merged them into one node with the two sets of users.

Fix. Compiler side: the merge step repoints users and drops the later node; a surviving pair means the repointing loop missed a reference — check named inputs as well as operands, and the graph's own Sink, FunctionInputs and FunctionOutputs. Author side: report the file; the output is still correct, just larger than it should be.

DSH4323

Severity error

Message

Node {0} needs property '{1}' and does not have it.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:492

Cause. A node is missing a property its op cannot do without: Constant without Value, Parameter or TextureParameter without ParameterName, FunctionInput without InputName, FunctionOutput without OutputName, Custom without Code.

Fix. Compiler side: set these in the same function that creates the node. Author side: a uniform with no name is impossible to write, so report the file.

DSH4324

Severity error

Message

Node {0} carries a property with no name.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:432, Source/DreamShaderLang/Private/IR/IRValidator.cpp:445, Source/DreamShaderLang/Private/IR/IRValidator.cpp:467

Cause. Three shapes: a property with no name, the same property set twice on one node, or a property whose stored kind is not the kind the IR defines for that name (Value and DefaultValue are Float4, SortPriority is Int, Code is String, SamplerType is Enum, and so on — Prop:: in IR.h spells each one). The kind table is applied only to the IR's own property names and never to a Reflected node, whose properties are engine names passed through.

Fix. Compiler side: build properties with the matching FIRPropertyValue::Make* factory. A SortPriority stored as MakeFloat reads back as 0 in the emitter. Author side: report the file.

DSH4325

Severity error

Message

Node {0} writes attribute '{1}', which is not in the engine's material attribute table.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:886, Source/DreamShaderLang/Private/IR/IRValidator.cpp:904

Cause. An attribute name written into a MakeMaterialAttributes, SetMaterialAttributes, GetMaterialAttributes or MaterialSink node — or listed in AttributeSetTypes — is not in the engine's material attribute table. The table comes from the catalog and matching is case-sensitive.

Fix. Author side: check the spelling of the m.<Attribute> you wrote; the accepted names and their aliases are what the material editor's Break Material Attributes node lists (EmissiveColor, not Emissive Color). Compiler side: if the attribute is real, the catalog's MaterialAttributes array is missing it — re-export the manifest.

DSH4326

Severity error

Message

Product {0} has no name; the asset name comes from the exported function or from '/// @name'.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:1641, Source/DreamShaderLang/Private/IR/IRValidator.cpp:1654

Cause. A product has an empty Name, or two products of one file would be called the same thing. The asset name comes from the exported function's name or from /// @name, and two assets of one name in one destination folder would overwrite each other.

Fix. Author side: give one of the two exported functions a different name, or a different /// @name. Note that @name with a full /Game/... path sets the whole path, and only the leaf has to be unique. Compiler side: the binder decides product names; check FBoundProduct::AssetName.

DSH4327

Severity error

Message

Node {0} calls local product {1}, which this module does not have; it has {2}.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:825, Source/DreamShaderLang/Private/IR/IRValidator.cpp:837, Source/DreamShaderLang/Private/IR/IRValidator.cpp:853

Cause. A FunctionCall node does not say what it calls. It needs either Prop::LocalFunction (the index of another product of this module, for a call to an export in the same file) or a non-empty function asset path — Prop::FunctionPath, or ClassName. A local index that is out of range, or that points at the product the node itself belongs to, is the same failure.

Fix. Compiler side: a call to an ExportFunction of the same file gets LocalFunction; a call to an Extern gets the @asset path. A product calling itself means recursion got past DSH6200. Author side: check that the extern prototype has its /// @asset /Game/... line.

DSH4328

Severity warning

Message

Layout hint {0} of product {1} has kind '{2}'; a hint is spelled exactly 'Node' or 'Comment', so this one places nothing.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:1261, Source/DreamShaderLang/Private/IR/IRValidator.cpp:1273, Source/DreamShaderLang/Private/IR/IRValidator.cpp:1283, Source/DreamShaderLang/Private/IR/IRValidator.cpp:1294

Cause. A #pragma layout(...) hint is not one the layout pass can apply: its kind is neither Node nor Comment, a Node hint names no variable, or a Comment hint has no title. A warning, not an error: the product still compiles and the automatic layout still runs; only this hint places nothing.

Fix. Author side: write #pragma layout(Node, Var = Tint, X = 10, Y = 20) or #pragma layout(Comment, Name = "Lighting", X = 0, Y = 0, W = 400, H = 200). Compiler side: hints are carried through untouched from FBoundModule::LayoutHints, so the parse is the place to look.

DSH4329

Severity error

Message

Product {0} is a material instance, which assigns its parent's parameters and has no graph, and it carries {1} node(s), a sink or a function signature.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:1366

Cause. An IR product of kind MaterialInstance carries graph nodes, a sink or a function signature. An instance only assigns its parent's parameters. This is an internal consistency check of the IR validator: no source text can cause it.

Fix. Report it with the .dsi that produced it; it is a defect of the compiler.

DSH4330

Severity error

Message

Material instance product {0} needs the material it is an instance of, and its parent reference is empty.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:1377

Cause. A MaterialInstance product has no parent reference. The binder refuses a .dsi without a Parent earlier (DSH7250, DSH7252), so reaching this is an internal error.

Fix. Report it with the source that produced it.

DSH4331

Severity error

Message

Override '{0}' of product {1} is a {2} override holding a {3} value, and a {2} override holds {4}.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:1403, Source/DreamShaderLang/Private/IR/IRValidator.cpp:1416

Cause. An instance override holds a value of another kind than its parameter kind takes -- a Scalar is one number, a Vector four, a StaticSwitch a bool, an asset kind an object path -- or a Font override names a negative page. Internal consistency check: the binder refuses both in source (DSH7259, DSH7266).

Fix. Report it with the source that produced it.

DSH4332

Severity error

Message

Product {0} overrides '{1}' twice, and an instance sets each parameter once.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:1433

Cause. One parameter is overridden twice in an instance product. The binder reports the same thing on the source (DSH7261); this is the validator's backstop.

Fix. Remove one of the two uniform lines of that name from the .dsi.

DSH4333

Severity error

Message

Override '{0}' of product {1} names a parameter, and the parent schema the product carries has no such parameter.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:1449, Source/DreamShaderLang/Private/IR/IRValidator.cpp:1459

Cause. An instance product overrides a parameter its parent schema does not list, or lists under another kind. The binder checks both against the same schema (DSH7258, DSH7259), so reaching this means the two saw different schemas.

Fix. Rebuild the parent first, then the instance; if it persists, report it.

DSH4334

Severity error

Message

This module holds a material instance and {0} other product(s), and a material instance is the only product of its file.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:1613, Source/DreamShaderLang/Private/IR/IRValidator.cpp:1627

Cause. A module holds a material instance together with other products. A .dsi is one instance and nothing else; the front end refuses functions and other declarations in it, so this is the validator's backstop.

Fix. Keep each instance in a .dsi of its own.

DSH4335

Severity error

Message

Material instance product {0} carries backend {1}, and an instance is a plain material instance with the default backend.

Raised by Source/DreamShaderLang/Private/IR/IRValidator.cpp:1387

Cause. A MaterialInstance product carries a backend. Backend is a property of a material; an instance is always a plain UMaterialInstanceConstant.

Fix. Remove Backend from #pragma instance(...).

DSH4350

Severity error

Message

The IR builder cannot read '{0}' here: the binder typed what it is read from as a material, but that did not lower to one.

Raised by Source/DreamShaderLang/Private/IR/IRBuilderExpressions.cpp:386, Source/DreamShaderLang/Private/IR/IRBuilderExpressions.cpp:516

Cause. The IR builder reached a bound expression whose EBoundExprKind it has no case for. This is an internal error, not an authoring mistake: the binder produced a record the builder was not written against, which happens when a new expression kind is added to LangBound.h and only one of the two sides is updated.

A second message under this code is the same kind of seam: a field read such as X.Roughness whose object the binder typed material but which did not lower to one. Every producer of a material value -- a material parameter, a reflected node's MaterialAttributes output (UE.BlendMaterialAttributes(...)), a function call's material result, an out material written back -- hands it over as an attribute map with that output as its source, so reaching this message means a producer was added or changed on one side only.

Fix. Nothing an author can do in the source. Report the file and the line; the fix is a new case in FIRBuilder::LowerExpr (for the field read, the producer that handed back a bare value). Until then, rewriting the expression in a simpler form usually avoids the kind that has no lowering.

DSH4352

Severity error

Message

This module was bound without a builtin catalog, so no 'UE.*' call and no material attribute can be named; run the bind with a catalog, or pass one in FIRBuildOptions.

Raised by Source/DreamShaderLang/Private/IR/IRBuilder.cpp:121, Source/DreamShaderLang/Private/IR/IRBuilderExpressions.cpp:1582, Source/DreamShaderLang/Private/IR/IRBuilderExpressions.cpp:915, Source/DreamShaderLang/Private/IR/IRBuilderMaterial.cpp:420, Source/DreamShaderLang/Private/IR/IRBuilderMaterial.cpp:532

Cause. Three shapes, told apart by where the message points.

At the top of the file: BuildDreamShaderIR ran with no builtin catalog at all -- neither FBoundModule::Catalog (which the binder sets) nor the FIRBuildOptions::Catalog override. The catalog is engine knowledge -- expression classes, their pins, the material attribute table -- and DreamShaderLang cannot look any of it up itself, so nothing that needs naming can be lowered: no UE.* or Substrate.* call, no material attribute such as m.BaseColor. It is reported once for the whole module rather than once per line.

At a particular attribute or UE.* call: a catalog is present but does not have the attribute or expression index the binder recorded, which means the bind and the build read different catalogs -- a stale exported manifest against a newer engine, most often.

At the material's entry function: the entry's material was replaced as a whole -- m = UE.BlendMaterialAttributes(...), or m handed to a material function that writes an inout material back -- so what reaches the material's output is one attribute set, which goes in through the material's MaterialAttributes input, and the catalog's attribute table has no MaterialAttributes entry to name that input by.

Fix. Inside a compile none of the three can happen; the pipeline binds and builds against one catalog filled from reflection, and reflection always adds the MaterialAttributes entry. From a tool, pass the catalog: dsc export-catalog writes the JSON form and LoadBuiltinCatalogFromJson reads it back, and the same one has to reach both FBindOptions::Catalog and the build. Re-export the manifest after an engine upgrade. A catalog that is present but empty means the reflection pass ran before the engine's material expression classes were loaded.

DSH4360

Severity error

Message

This loop runs a number of times the compiler cannot fix at {0} or fewer, and a material graph has no loops; give it a constant trip count, or move it into a '/// @custom' function.

Raised by Source/DreamShaderLang/Private/IR/IRBuilderStatements.cpp:425

Cause. A for, while or do whose trip count the binder could not prove constant, or proved to be larger than MaxUnrolledIterations (64 by default). A material graph has no loops at all: the only way a loop can exist in one is to be unrolled at compile time, and that needs a count known before the shader runs.

Fix. Give the loop a constant bound -- for (int i = 0; i < 8; ++i), with 8 a literal or a static const, and a step the binder can follow. A loop over a uniform count cannot be unrolled by definition; move it into a /// @custom function, where the body is HLSL and the shader compiler does the loop properly. A very long unroll (hundreds of iterations) is usually a mistake in the graph even when it is legal: it puts one node per iteration into the asset.

DSH4361

Severity error

Message

This expression is {0} and the material graph has no matrices; compute it inside the custom body instead.

Raised by Source/DreamShaderLang/Private/IR/IRBuilderExpressions.cpp:254

Cause. An expression is a matrix (float3x3, float4x4) and something wanted its value. A material graph has no matrix pins: the engine's transform nodes take a vector and a basis, not a matrix, so there is nowhere to put one.

Fix. For a coordinate-space change use UE.Transform / UE.TransformPosition, which is what the graph offers instead of a matrix. For real matrix maths, move the whole calculation into a /// @custom function and pass the vectors in and out; the matrix then lives inside the HLSL, where it is free.

DSH4362

Severity error

Message

'discard' has no material-graph form; set the material's OpacityMask to zero instead, or move the branch into a '/// @custom' function.

Raised by Source/DreamShaderLang/Private/IR/IRBuilderStatements.cpp:125

Cause. discard in a body that becomes a graph. The material graph has no early-out: a material is an expression per output pin, and every pin is evaluated.

Fix. Write the cull as an opacity mask -- set m.OpacityMask to 0 where you would have discarded and to 1 elsewhere, and set the material's blend mode to Masked -- which is what the engine does with discard anyway. A /// @custom function may not use discard either, for the same reason: its code is one expression inside a bigger shader.

DSH4363

Severity error

Message

'{0}' inside an 'if' cannot be unrolled, because both arms of the 'if' become nodes and only one of them may leave the loop; move it to the top of the loop body, or write the loop in a '/// @custom' function.

Raised by Source/DreamShaderLang/Private/IR/IRBuilderStatements.cpp:114

Cause. A break or continue inside an if inside a loop the builder is unrolling. Unrolling turns the loop body into nodes and an if into a Select over both arms -- so both arms happen, and "leave the loop" is not something one of them can do.

Fix. Move the break to the top level of the loop body, where the unroller can simply stop emitting iterations (its condition has to be something the compiler settles, not something the shader computes). If the exit genuinely depends on a value the shader computes, the loop is not a graph loop: move it into a /// @custom function.

DSH4364

Severity error

Message

A parameter of type {0} cannot be a material function input; the graph has no pin that carries one.

Raised by Source/DreamShaderLang/Private/IR/IRBuilderMaterial.cpp:251

Cause. An exported function has a parameter whose type cannot be a material function input. SamplerState and user struct parameters are the usual two: the engine's UMaterialExpressionFunctionInput has a fixed list of types (scalar, the three vector widths, the texture kinds, static bool, MaterialAttributes, Substrate) and neither is on it.

Fix. For a sampler, drop the parameter: a texture input carries its own sampler. For a struct, pass the fields as separate parameters -- a struct is a compile-time aggregate in DreamShaderLang and has no run-time form to hand across an asset boundary. If the function is only ever called from this file, drop export: an internal helper takes any type, because it is inlined.

DSH4365

Severity error

Message

A struct has no graph form; pass one of its fields, or move the whole thing into a '/// @custom' function.

Raised by Source/DreamShaderLang/Private/IR/IRBuilderExpressions.cpp:183, Source/DreamShaderLang/Private/IR/IRBuilderExpressions.cpp:536

Cause. A struct value reached a place that needs one graph value -- a pin, an operand, a material attribute. A struct in DreamShaderLang is a compile-time aggregate: it exists to group values while the file is being compiled and is flattened away, so it has no single node.

Fix. Use the field you meant (Inputs.Roughness, not Inputs). To pass a whole struct to something, make the callee an internal helper, which is inlined and can take it.

DSH4366

Severity error

Message

'{0}' is a constant texture, which is a TextureObject node, and this engine has no such material expression; declare it 'uniform'.

Raised by Source/DreamShaderLang/Private/IR/IRBuilderMaterial.cpp:640

Cause. A static const texture (in 1.x, const Texture2D T = Path(...)) is built as a TextureObject node, and the builtin catalog of this engine has no such class. Stock engines all have it; a stripped-down catalog, or one loaded from an incomplete manifest, may not.

Fix. Declare the texture uniform (a texture parameter), or re-export the catalog (dsc export-catalog) if a stale manifest is in use.

DSH4370

Severity error

Message

'{0}' is read before anything wrote it; a material attribute has no value until this function assigns one.

Raised by Source/DreamShaderLang/Private/IR/IRBuilderMaterial.cpp:453

Cause. A material attribute was read before anything wrote it: float r = m.Roughness; in a function where no m.Roughness = ... came first. A material is a write-then-read record while a file compiles -- there is no "current value" of a pin nobody has connected.

Fix. Assign the attribute before reading it. In a /// @layer or /// @layerblend function the incoming material is a real value and reading an attribute of it is fine -- that is what BreakMaterialAttributes is for -- so this message in a layer means the read is of the result material, not of an input one. A material that came out of a node is a real value in the same way: UE.BlendMaterialAttributes(...).Roughness, a material function call's material result, or m after m = UE.BlendMaterialAttributes(...) all read the node's output, so this message never concerns one of those. A compound assignment (m.Roughness *= 0.5) and a write to one component (m.Normal.z = 1) read the attribute first -- the other components have to come from somewhere -- so either of those on an attribute nothing has set is this message too: set the whole attribute first.

DSH4371

Severity error

Message

A 'material' value reached a pin that carries {0}; only a MaterialAttributes pin accepts one.

Raised by Source/DreamShaderLang/Private/IR/IRBuilderExpressions.cpp:173, Source/DreamShaderLang/Private/IR/IRBuilderExpressions.cpp:222

Cause. A material value was passed to something that cannot take one: a reflected node's pin that carries a number, or a function parameter declared as a numeric type. Only a MaterialAttributes pin accepts a material.

Fix. Pass the attribute rather than the material (m.BaseColor, not m), or change the parameter's type to material. When calling a material function asset that really does take MaterialAttributes, check that the extern prototype declares that parameter material.

DSH4372

Severity error

Message

'{0}' is assigned in only one arm of this 'if' and has no value before it; assign it in both arms, or give it a value before the 'if'.

Raised by Source/DreamShaderLang/Private/IR/IRBuilder.cpp:624, Source/DreamShaderLang/Private/IR/IRBuilder.cpp:648

Cause. A variable or a material attribute is assigned in one arm of an if or ?: and not in the other, and had no value before the branch. Both arms become nodes and a conditional picks between them, so the arm that does not assign still has to have something to select.

Fix. Give the variable a value before the if (float x = 0;), or assign it in both arms. For a material attribute, set it before the if -- m.Roughness = 0.5; then override it in the arm that needs to. In a layer function, reading the incoming material supplies the missing arm on its own, so this only appears when the attribute has no incoming value either.

When the compiler can already tell which arm runs -- if (i > 0) in the first trip of an unrolled for (int i = 0; ...) -- and the arm without a value is the one that does not run, nothing is missing and nothing is reported: the value is the other arm's on every path the shader takes.

DSH4373

Severity error

Message

'{0}' is a property of {1} and needs a literal; this argument is computed at run time.

Raised by Source/DreamShaderLang/Private/IR/IRBuilderExpressions.cpp:1014

Cause. An argument bound to a property of a reflected node is not a literal. A property is written into the asset when it is generated (a SceneTextureId, a ParameterName, a coordinate index); it is not a pin and there is nothing to connect a computed value to.

Fix. Write a literal: UE.TexCoord(Index = 0), not UE.TexCoord(Index = SomeUniform). A static const also works, because the binder folds it before the builder sees it. If the value has to vary, look for a pin of the same name -- many classes have both, and the pin is the one that takes an expression.

DSH4374

Severity error

Message

This builds a {0}-component value, but a material graph carries at most four components.

Raised by Source/DreamShaderLang/Private/IR/IRBuilder.cpp:1120

Cause. A constructor, a swizzle or a coercion asked for more than four components: float4(A.rgb, B.rg) is five. Material graph values are float1 to float4 and AppendVector cannot make anything wider.

Fix. Count the components. The usual cause is appending a vector where a scalar was meant -- float4(Colour, Alpha.r) rather than float4(Colour, Alpha) when Alpha is a float2.

DSH4375

Severity error

Message

The two sides of this branch end with a different whole material, and DreamShader chooses between attribute values, not between whole materials; assign the attributes one at a time on both sides, or mix the two materials with UE.BlendMaterialAttributes.

Raised by Source/DreamShaderLang/Private/IR/IRBuilderStatements.cpp:846, Source/DreamShaderLang/Private/IR/IRBuilderStatements.cpp:850

Cause. The two arms of an if -- or the two sides of a ?:, or a return inside an if and the code after it -- leave a different whole material in the same variable. One arm replaced the material (m = UE.BlendMaterialAttributes(...), R = A, or a material function call that writes an inout material back) and the other did not, or each arm replaced it with a different one. A branch is lowered by choosing, attribute by attribute, between what the two arms left behind; a whole material is not an attribute value, and on the side that did not replace the material an attribute nobody wrote has no value the compiler can name to choose against. The same holds one attribute down: m.MaterialAttributes holds a whole material, so writing a different one to it in each arm is this error as well -- never a numeric conditional over two materials.

Fix. Write the attributes you need in both arms instead of replacing the material in one of them. To choose between two whole materials, mix them: m = UE.BlendMaterialAttributes(A = First, B = Second, Alpha = Mask); with the mask at 0 or 1 does what the branch meant. A static switch between two whole materials (a StaticSwitch over MaterialAttributes) is not generated in this version.

DSH4376

Severity error

Message

'{0}' is read here, but nothing gives it a value on any path that reaches this line; assign it first, or give it an initializer where it is declared.

Raised by Source/DreamShaderLang/Private/IR/IRBuilderExpressions.cpp:1459

Cause. A local is read -- or compound-assigned (x += 1, ++x), which reads it first -- at a point that no path through the function has given it a value: float x; m.Opacity = x;. A material graph has no "uninitialised": the read would lower to nothing, and whatever it fed would quietly not be connected. Reading a field of a struct local that nothing wrote (P.B) is the same error, named by the field.

Not reported, on purpose: a local assigned in only one arm of an if (that is DSH4372, once); a parameter (an out one nobody assigns is the binder's DSH6211); a local handed to an out or inout argument, since the callee may only write it; and a read inside an if arm the compiler can tell never runs, such as if (i > 0) on the first trip of an unrolled loop. Each read site is reported once, and a later read of the same local on the same path is not reported again.

Fix. Give the local a value before the read: an initializer where it is declared (float x = 0;), or an assignment on every path that reaches the read. Writing a vector local one component at a time is fine -- float3 v; v.x = a; v.y = b; -- because a component write starts from zero, the value the 1.x generator gave a declaration with no initializer; what is refused is reading v, or a component of it, before anything was written.

DSH4377

Severity error

Message

'{0}' writes into the material held in an attribute, and an attribute takes one whole value, not a write to part of it; assign that attribute a whole material, or set the attribute on the material itself.

Raised by Source/DreamShaderLang/Private/IR/IRBuilderExpressions.cpp:1475

Cause. An assignment writes into the material an attribute holds: m.MaterialAttributes.Roughness = 0.5. While a file compiles a material is a map from each attribute to one value. What m.MaterialAttributes holds is a whole attribute set, and the map has no record inside a record, so a write to part of it has nothing to lower to. Reading such a field is fine: m.MaterialAttributes.Roughness on the right of = reads it off the stored set.

Fix. Set the attribute on the material itself (m.Roughness = 0.5), or give the attribute a whole material, such as the result of UE.BlendMaterialAttributes(...). Writing one component of an ordinary attribute (m.BaseColor.x = 1) is not this error: that is a read-modify-write of the attribute, the same as one component of a local.

DSH4378

Severity error

Message

A branch chooses between two {0} values or between two numbers, and this one has one of each.

Raised by Source/DreamShaderLang/Private/IR/IRBuilder.cpp:1538, Source/DreamShaderLang/Private/IR/IRBuilder.cpp:1556

Cause. A branch over Substrate values that cannot be built. Two messages: one side of the branch is a Substrate value and the other a number; or the branch is decided at run time, which becomes a Substrate.Select node, and this engine has none (the node exists from Unreal Engine 5.6 on).

Fix. Give both sides the same kind of value. On an engine without Substrate.Select, make the condition a /// @static uniform bool -- a StaticSwitch carries a Substrate value -- or mix the two values with lerp().

DSH4379

Severity error

Message

A branch can only choose between numbers, bools and static Substrate values, and these are {0} objects, which no material graph node switches; sample each texture first and branch on the samples.

Raised by Source/DreamShaderLang/Private/IR/IRBuilder.cpp:1527

Cause. A branch leaves a texture object or a sampler in a variable, with a different one on each side. No material graph node chooses between two texture objects, static condition or not.

Fix. Sample both textures and branch on the sampled colours; with a /// @static condition only the taken side ends up in the shader.

DSH4380

Severity warning

Message

This branch becomes a 'Substrate.Select', which parameter-blends its two inputs; they are a '{0}' and a '{1}', and the engine may refuse to blend unlike BSDFs.

Raised by Source/DreamShaderLang/Private/IR/IRBuilder.cpp:1571

Cause. A run-time if or ?: chooses between two Substrate values of unlike kinds -- a slab on one side and an Unlit on the other, say. The branch becomes a Substrate.Select node, and Select always parameter-blends its two inputs; which pairs of BSDFs the engine can blend is the engine's business, and it reports the ones it cannot when the material compiles. This is a warning: the node is made.

Fix. Nothing, if the material compiles. If the engine refuses the pair, choose statically instead (/// @static on the condition makes a StaticSwitch, which carries any Substrate value), or build both sides from the same node.

DSH4381

Severity error

Message

'{0}' is converted by the node 'Substrate.{1}', and this engine has no such node; give the pins it feeds directly.

Raised by Source/DreamShaderLang/Private/IR/IRBuilderSubstrate.cpp:507

Cause. A virtual argument of a Substrate call -- BaseColor / Metallic / Specular, Haziness, Transmittance / Thickness -- stands for a conversion node in front of the BSDF (Substrate.MetalnessToDiffuseAlbedoF0, Substrate.HazinessToSecondaryRoughness, Substrate.TransmittanceToMFP), and the catalog of this engine has no such node. The binder accepted the argument because the node's name is known; the builder found nothing to make.

Fix. Give the pins the conversion would have fed directly (DiffuseAlbedo and F0, SecondRoughness and SecondRoughnessWeight, SSSMFP). If the engine does have the node, the catalog is stale: run dsc export-catalog again.

DSH4382

Severity error

Message

This material drives FrontMaterial and says 'Substrate = Native', and Substrate is off in this project; the engine could not compile the asset. Turn Substrate on, or write 'Substrate = Bridge' and the legacy attributes.

Raised by Source/DreamShaderLang/Private/IR/IRBuilderSubstrate.cpp:416

Cause. The material says #pragma material(Substrate = Native), drives FrontMaterial, and Substrate is off in this project (r.Substrate, the built-in define DS_SUBSTRATE). The engine cannot compile such an asset, so it is refused here, where the message can say why, instead of as a shader error later.

Fix. Turn Substrate on in the project, or write the material against the legacy attributes and say Substrate = Bridge: that builds as written where Substrate is off and as one Substrate.ShadingModels node where it is on.

DSH4383

Severity error

Message

'{0}' is not the Substrate value being built any more when a loop comes round to '{0}.{1}': an earlier trip assigned it. Declare the value inside the loop, or finish it before the loop.

Raised by Source/DreamShaderLang/Private/IR/IRBuilderSubstrate.cpp:201, Source/DreamShaderLang/Private/IR/IRBuilderSubstrate.cpp:247, Source/DreamShaderLang/Private/IR/IRBuilderSubstrate.cpp:277, Source/DreamShaderLang/Private/IR/IRBuilderSubstrate.cpp:304

Cause. A Substrate value that is built member by member (Substrate S = Substrate.Slab(); S.Roughness = r;) meets a loop that comes round. The binder checks a builder in source order and cannot see a loop's second trip, so the builder of the graph says so, in four cases: a member is written after an earlier trip of the loop already used the value (its node is what it was then); a member is accessed after an earlier trip assigned the local a whole value, which has no members; a member is read, or is the left side of *= and its kin, on a path where the line that writes it did not run.

Fix. Declare the value inside the loop -- a builder declared in the body is a new value on every trip -- or finish writing it before the loop starts. For the last two cases, give the member a value on every path before it is read.

DSH4390

Severity info

Message

'{0}' is declared but nothing reads it, so it is not in the generated material.

Raised by Source/DreamShaderLang/Private/IR/IRPasses.cpp:872

Cause. Informational. A uniform is declared but nothing in the file reads it, so no parameter node was generated and the material has no such parameter. The passes report it after pruning, so it also fires for a uniform that is only read by code that itself turned out to be dead.

Fix. Delete the declaration, or use it. If a material instance is meant to drive the parameter, note that a parameter that feeds nothing does nothing: the instance would show a knob with no effect, which is why it is not generated. If it is read only inside #if text that is currently off, the message is expected.

DSH4400

Severity error

Message

Buffer '{0}' is declared twice; the declaration on line {1} already makes it.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderPipeline.cpp:1541, Source/DreamShaderLang/Private/Semantic/LangBinderPipeline.cpp:1555, Source/DreamShaderLang/Private/Semantic/LangBinderPipeline.cpp:1568

Cause. A buffer is declared under a name that is taken. Three messages:

• the same name was declared as a buffer before; the first declaration stands and this one is dropped;
• the name differs from a buffer declared before in case only (Buffer 'mask' differs from 'Mask', declared on line 2, in case only; ...): names are case-sensitive in the source, but the pipeline asset keeps buffer names as Unreal names, which compare ignoring case, so the two would be one buffer there. The first declaration stands;
• the name is a uniform or static const of the pipeline, or DreamPassWeight ('Mask' already names a parameter or a constant of this pipeline; ...): buffers, parameters and constants share one namespace, and the buffer is the one refused, wherever it stands in the file.

A refused declaration makes nothing: a binding of the same name binds the first buffer; a binding of a refused case-only spelling, or of a name a parameter has, is DSH4403.

Fix. Rename one of the two, or merge two declarations of one buffer -- their arguments go in one list: buffer Mask : R8(Clear = 0, Scale = 0.5);.

DSH4401

Severity error

Message

A pass named '{0}' is already declared on line {1}; RDG events and stats are named after passes, so each name is used once.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderPipeline.cpp:1811, Source/DreamShaderLang/Private/Semantic/LangBinderPipeline.cpp:1824

Cause. Two passes of one pipeline have the same name, or names that differ in case only (Pass 'blur' differs from 'Blur', declared on line 7, in case only; ...): the pipeline asset keeps pass names as Unreal names, which compare ignoring case, so Blur and blur would be one pass there. The runtime names a pass's GPU event and its stats after it, <Pipeline>.<Pass>, so a name has to point at one pass. The second pass is skipped whole: nothing in it is checked or built until it is renamed.

Fix. Rename one of them, preferably after what it does: BlurH and BlurV rather than two Blurs.

DSH4402

Severity error

Message

'{0}' is a built-in texture a pass binds without declaring it, and cannot be declared as a buffer.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderPipeline.cpp:1530

Cause. A buffer declaration uses the name of a built-in texture: SceneColor, SceneDepth, CustomDepth, CustomStencil, GBufferA to GBufferF, Velocity or Translucency. A pass binds those by name without declaring them, so a buffer of the same name could not be told apart from the renderer's texture. The declaration is dropped, and a binding of the name still binds the built-in.

Fix. Give the buffer a name of its own. For a copy of a built-in texture, declare the buffer and fill it with a copy pass (read SceneColor; write Grab;); for a mesh pass's private depth, declare buffer MaskDepth : Depth32; and write Depth = Own(MaskDepth);.

DSH4403

Severity error

Message

'{0}' is neither a buffer of this pipeline nor a built-in texture; declare it with 'buffer {0} : <Format>;'.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderPipeline.cpp:1509

Cause. A pass names a buffer that does not exist: in a read or write binding, in Dispatch = <Buffer> (or <Buffer> / n, <Buffer> * n), or in Depth = Own(<Buffer>). Names are case-sensitive; when a declared buffer or a built-in texture differs only in case, the message suggests it (read sceneColor;). A pass binds the pipeline's own buffers and the built-in textures only: a Texture2D parameter, or another pipeline's buffer, is no buffer here. A buffer whose declaration was refused (DSH4400) is not declared either, so its bindings land here too.

Fix. Declare the buffer -- buffer Blurred : R8(Scale = 0.5); -- or correct the name. To hand a texture parameter to a pass, draw the pass with a material and give it to the material with param.

DSH4404

Severity error

Message

'{0}' is not a 'uniform' or 'static const' of this pipeline; 'Enabled' takes a 'uniform bool' or 'true'.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderPipeline.cpp:1056, Source/DreamShaderLang/Private/Semantic/LangBinderPipeline.cpp:2608

Cause. A name in a pipeline value is not declared. Two places raise it:

• Enabled = <Name>, in #pragma pipeline(...) or in a pass, names neither a uniform nor a static const. true and false are lower case: Enabled = True is a name.
• a param expression uses a name that is not a uniform, a static const or DreamPassWeight ('Radius' is not a 'uniform' or 'static const' of this pipeline, nor 'DreamPassWeight'.): a misspelt parameter, a buffer (param Size = Mask;), a name only the pass's shader or material knows.

A variable refused by DSH3316 is not declared either. When a declared name differs only in case, the message suggests it.

Fix. Correct the name, or declare the value at file scope: a uniform bool for Enabled, a uniform or static const for a param. A buffer reaches a pass through read, which in an HLSL pass also defines its size as <Name>Size.

DSH4405

Severity error

Message

'{0}' is a '{1}', and 'Enabled' takes a 'uniform bool' or 'true'.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderPipeline.cpp:1070

Cause. Enabled, in #pragma pipeline(...) or in a pass, names a declared value that is not one bool: a uniform float, an int, a vector. A pipeline or a pass is switched by a bool alone.

Fix. Declare a uniform bool and name it:

#pragma pipeline(Enabled = bShowOutline)

uniform bool bShowOutline = true;

A pipeline needs no Enabled to fade out: it does not run at weight 0, and every pass receives the weight (DreamPassWeight in a material, DP_Weight in a .usf).

DSH4406

Severity error

Message

No material '{0}' was found: a bare name is the material a '.dss' under the same source root builds, an object path any material or material instance.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderPipeline.cpp:3530

Cause. The Material of a fullscreen or mesh pass resolves to nothing. A bare name ("PP_Outline") is looked up among the products of the DreamShader sources under the .dsp's source root -- the material a .dss exports, or a .dsi -- spelt exactly, case included; a material function does not count. An object path ("/Game/FX/PP_Outline.PP_Outline") has to name an asset that exists, or one a source under the source roots builds. The check needs the host to look the material up, which a compile in the editor or through dsc does; without that it is skipped (DSH7360).

Fix. Check the name against the export that builds the material, or write the object path, which is what a material outside this source root needs -- a hand-made one, or one another plugin's sources build. A bare name that several sources build is DSH8330.

DSH4407

Severity error

Message

'{0}' is not a '.usf' or '.ush' file; the engine compiles shader files of those two kinds only.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderPipeline.cpp:2026

Cause. Shader = names a file whose extension is not .usf or .ush (in any case): none at all ("Passes/Blur"), .hlsl, or a DreamShader source ("PP_Blur.dss"). The engine's shader compiler reads only those two kinds of file.

Fix. Give the shader file a .usf extension and write it in the path: Shader = "BoxBlur.usf";. A material is not a shader file: a fullscreen pass draws a .dss with Material = "...".

DSH4408

Severity error

Message

The shader file '{0}' does not exist; a path starting with '/' is a virtual shader path, and any other is read from the folder of this '.dsp'.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderPipeline.cpp:3735

Cause. The file Shader = names does not exist. A path that does not start with / is relative to the folder of the .dsp -- "BoxBlur.usf" sits next to it, "../Shared/Blur.usf" one folder up; a path that starts with / is a virtual shader path, which resolves only through a directory the engine maps (/Engine/..., /Plugin/<Name>/..., or a mapping a module adds with AddShaderSourceDirectoryMapping). Checked where DSH4406 is.

Fix. Correct the path or move the file. Next to the .dsp is the usual place, and it needs no mapped directory: the engine compiles a snapshot of the file, never the original. Use a virtual path only for a shader that already lives in a mapped directory.

DSH4410

Severity error

Message

'{0}' does not define a function '{1}'.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderPipeline.cpp:3802, Source/DreamShaderLang/Private/Semantic/LangBinderPipeline.cpp:3830, Source/DreamShaderLang/Private/Semantic/LangBinderPipeline.cpp:3842, Source/DreamShaderLang/Private/Semantic/LangBinderPipeline.cpp:3989, Source/DreamShaderLang/Private/Semantic/LangBinderPipeline.cpp:4023, Source/DreamShaderLang/Private/Semantic/LangBinderPipeline.cpp:4082

Cause. The Entry of an HLSL pass does not name a function the pass can run. Two messages:

• '<file>' does not define a function '<Entry>'. -- no function of that name is defined in what the check reads: the .usf, every file it includes by a relative path, and every file it includes by a virtual path a mapped shader directory resolves (/Project/..., a plugin's /Plugin/...), each followed through its own includes in turn. The engine's own headers (/Engine/, /ThirdParty/) are not read. Comments and # lines are skipped, a function counts when it has a body, and names are case-sensitive. When the file includes something the check cannot follow -- a virtual path no mapped directory covers, a relative path that names no file, #include MACRO -- an entry it did not find is not reported, since it may be in what was not read; a compute pass then needs Threads (DSH4411).
• '<Entry>' in '<file>' is a compute shader entry ... -- a fullscreen pass names a function with [numthreads(...)] in front of it. A fullscreen pass runs its Entry as the pixel shader of its slot, and a compute shader's entry is not one.

For HLSL written in the .dsp the same is checked against the text of the block, with no file to read:

• The 'hlsl' block of pass '<Pass>' does not define a function '<Entry>' ... -- the pass's own block holds whole functions, and none has the name Entry gives; or, with no Entry, none is Main, the entry of a block by default. The entry is a function of the block itself, not of a file the block includes;
• The file's 'hlsl' block does not define a function '<Entry>' ..., and ... names a function of the file's 'hlsl' block, and this '.dsp' has none -- a pass with no Shader and no block of its own runs the entry of the file's block that Entry names;
• '<Entry>' is a compute shader entry ... -- as above, for a fullscreen pass.

Checked where DSH4406 is, once the file is found; for code in the .dsp, whenever the pipeline binds.

Fix. Spell Entry as the function is spelt in the HLSL -- Entry = BlurCS; -- and define the function in the .usf or in a file it includes; for code in the .dsp, in the block it is looked for in -- the pass's own, or the file's when the pass has neither Shader nor a block. A fullscreen pass names its pixel shader function, the one that returns SV_Target0; to run a [numthreads] function, make the pass compute.

DSH4411

Severity error

Message

'{0}' in '{1}' has no '[numthreads(x, y, z)]' the compiler can read; write 'Threads = uint3(x, y, z)' in the pass.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderPipeline.cpp:3790, Source/DreamShaderLang/Private/Semantic/LangBinderPipeline.cpp:3816, Source/DreamShaderLang/Private/Semantic/LangBinderPipeline.cpp:4069

Cause. A compute pass's Entry has a thread group size the compiler cannot read, and the pass gives no Threads to say it. The dispatch is counted in groups of that size. Two messages:

• '<Entry>' in '<file>' has no '[numthreads(x, y, z)]' ... -- the function is there, but there is no [numthreads(...)] in front of it, or its three values are not plain whole numbers -- typically a macro, [numthreads(THREADGROUP_SIZE, THREADGROUP_SIZE, 1)].
• '<Entry>' is not in what the compiler could read of '<file>', which includes a file it cannot follow ... -- the function was not found, and the file includes something the check cannot read (DSH4410 lists what), so the function may be defined there, with a group size nobody read.
• '<Entry>' has no '[numthreads(x, y, z)]' in front of it ... -- the same as the first, for an entry written in the .dsp.

Fix. Write the group size as numbers in the shader -- [numthreads(8, 8, 1)] -- or keep the macro and give the same size in the pass: Threads = uint3(8, 8, 1);. For the second message, give Threads as well, or include the file by a path the compiler can follow.

DSH4412

Severity error

Message

'{0}' is not a pass layer of this project; the layers are the first {1} names of Project Settings > DreamPlugin > DreamShader Custom Pass > Layer Names.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderPipeline.cpp:3510

Cause. A mesh pass's Filter selects by Layer(...) a name the project does not have. Pass layers are the project's: the first 32 names of the Layer Names list of Project Settings ▸ DreamPlugin ▸ DreamShader Custom Pass, which the message names; only those have a bit, so a name further down the list is no layer either. The name is compared case-sensitively, and when a layer differs from it only in case the message suggests that one instead ('<Layer>' is not a pass layer of this project; did you mean '<Name>'?). There is one error per unknown name, at the Filter line. Checked where DSH4406 is.

Fix. Add the layer to that list, within its first 32 names, or correct the name. The list's order is the layers' bit order, so add new names at the end: moving one re-targets every compiled pipeline that names it until that pipeline compiles again. List(Name) is not checked here -- a list is filled at run time by UDreamPassSubsystem::AddToList.

DSH4413

Severity error

Message

'Threads = uint3({0}, {1}, {2})' disagrees with '[numthreads({3}, {4}, {5})]' of '{6}', and the dispatch would be sized for groups the shader does not have; leave 'Threads' out, or write the same numbers.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderPipeline.cpp:3775, Source/DreamShaderLang/Private/Semantic/LangBinderPipeline.cpp:4056

Cause. A compute pass writes Threads = uint3(...), and the [numthreads(...)] of its entry, which the compiler can read -- in the .usf, or in the .dsp when the entry is written there -- says other numbers (the message gives both). The number of groups is worked out from Threads while the shader runs groups of [numthreads], so the pass would cover too much or too little of its buffer. Threads = uint2(x, y) counts as z = 1.

Fix. Leave Threads out: the group size is read from [numthreads]. Threads is for an entry whose group size is a macro (DSH4411), and then it states the size the macro gives.

DSH4414

Severity error

Message

'DreamPassWeight' is the pipeline's weight in a view, which every pass can read as 'param P = DreamPassWeight'; it cannot be declared.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderPipeline.cpp:838

Cause. A uniform or static const of a .dsp is called DreamPassWeight. The name is the pipeline's weight in the view -- the largest weight of its activations, which is how a volume's fade reaches the effect -- and the runtime supplies it. The declaration is dropped. A buffer of that name is DSH4400.

Fix. Rename the declaration. The weight needs none: every pass receives it, a material as its scalar parameter DreamPassWeight and a .usf as DP_Weight, and param Fade = DreamPassWeight * 0.5; hands it on under another name, scaled.

DSH4415

Severity error

Message

'{0}.Previous': a built-in texture keeps no history.

Raised by Source/DreamShaderLang/Private/Semantic/LangBinderPipeline.cpp:2497, Source/DreamShaderLang/Private/Semantic/LangBinderPipeline.cpp:2507

Cause. A read names .Previous, last frame's contents, of a texture that keeps none. Two messages:

• a built-in texture, as in read SceneColor.Previous; -- the renderer's textures hold this frame only;
• a buffer of the pipeline declared without History = true ('Mask.Previous' reads last frame's 'Mask', and 'Mask' keeps none; ...).

Fix. For a buffer, add History = true to its declaration. For a built-in texture, keep a copy of your own with a history and read that copy's .Previous:

buffer LastColor : RGBA16F(History = true);

pass Keep : copy
{
    Injection = BeforePostProcess;
    read  SceneColor;
    write LastColor;
}

A pass then reads last frame's picture with read Prev = LastColor.Previous;.