Graph Language

Graph is the part of DreamShaderLang that becomes Unreal material nodes. It looks like a small shader language, but its statements are interpreted by the generator.

Statements

Common statements include:

float t = UE.Time();
float pulse = sin(t) * 0.5 + 0.5;
Color = Tint * pulse;

Declarations

float Strength = 1.0;
vec3 Color = Tint * Strength;

The declared name can be referenced later in the same Graph.

Expressions

Arithmetic

Color = Tint * Strength + vec3(0.1, 0.1, 0.1);

Constructors

vec3 Blue = vec3(0.2, 0.6, 1.0);
float4 Packed = float4(Blue, 1.0);

Swizzle

float r = Color.r;
vec2 rg = Color.rg;

MaterialAttributes

MaterialAttributes values are used by Material Layer and Layer Blend graphs.

MaterialAttributes Result = BaseMaterial;

Function Calls

Single-output calls can be used as value expressions:

float y = ColorTools::Luma(Tint);

Multi-output calls use explicit output variables.

Function Calls

Function calls become Custom-node helper calls or generated HLSL depending on the helper mode and compiler behavior.

float y = Luma(Tint);

GraphFunction Calls

GraphFunction calls can contain UE.* calls inside the helper body:

float pulse = Pulse(2.0);

ShaderFunction Calls

Generated .dsf functions can be called from other Graphs once imported:

vec3 result = F_Tint(Color, Strength);

The exact callable name follows the declaration/import symbol exposed by the source.

VirtualFunction Calls

VirtualFunction calls reference existing Unreal Material Function assets without generating them.

Use this when a project already owns the material function in Unreal.

Parameter Node Calls

Parameters are usually declared in Properties or Inputs, then referenced by name:

Color = Tint * Strength;

Explicit parameter node types can carry Unreal metadata such as group and sort priority.

if / else

Simple conditionals are supported for graph-friendly expressions:

if (UseTint)
{
    Color = BaseColor * Tint;
}
else
{
    Color = BaseColor;
}

For complex control flow, put the logic in a Function or GraphFunction.

Graph Region

Use #Region and #EndRegion to group a portion of a graph:

Graph = {
    #Region "Pulse"
    float t = UE.Time();
    float pulse = sin(t) * 0.5 + 0.5;
    #EndRegion

    Color = Tint * pulse;
}

Regions can work with generated layout comments and make decompiled graphs easier to review.

Not Currently Supported