SamplerType

DreamShader » Parameters » SamplerType

The metadata key that sets how a texture node interprets its texture: EMaterialSamplerType on the generated UMaterialExpressionTextureBase subclass.

Synopsis

<texture-token> <name> [ = <default> ] [ SamplerType = "<value>" [ ; <entry> … ] ] ;

(since 2.0.0) SamplerType has a path of its own on a declaration: on a compact texture token or TextureObjectParameter it becomes the 2.0 /// @sampler directive, a SAMPLERTYPE_ prefix removed, and is resolved by the emitter's enum-literal matcher (DSH8235 when nothing matches; an empty value is DSH7222). On a texture-sample token, which is expanded at its uses, it is an argument of the reflected node, checked against the engine catalog when the source is bound.

Applicable to every declaration whose generated node derives from UMaterialExpressionTextureBase:

Values

17 values. Each row is one enumerator; all four spellings in the row select it, and the comparison strips spaces, _, -, :, . and / and ignores case — so "linear color", "Linear-Color" and "linearcolor" are the same value as LinearColor.

There is no virtual counterpart for DistanceFieldFont or External.

[!NOTE] On a texture-sample token the value is checked against the 17 enumerator names the engine catalog lists (since 2.0.0). A spelling that normalizes to one of them (SAMPLERTYPE_Normal, linear color) is accepted with a DSH5278 warning; a DisplayName that is not also an enumerator name — Virtual Mask — is DSH5215. On a declaration all four spellings work.

[!NOTE] The enumerator list ends with the sentinel SAMPLERTYPE_MAX. It carries no Hidden metadata, so on a declaration [SamplerType="SAMPLERTYPE_MAX"] and [SamplerType="MAX"] resolve rather than erroring, and write a value that is not a sampler type. It is not a usable value. The catalog a texture-sample token is checked against does not list it (DSH5215).

Inference and override order

An explicit SamplerType always wins: the inference does not run at all on a node that has one. Omitting the key means the value follows the asset — which changes if the asset's compression settings change.

[!NOTE] The decompiler always emits SamplerType explicitly, even when it equals the inferred value, so a UMaterial → .dsm → UMaterial round trip does not drift when an asset is later recompressed.

SamplerSource

The companion key on UMaterialExpressionTextureSample subclasses — which sampler state the sample uses. It applies to the texture-sample tokens only, so its value is checked against the catalog as above.

The default is FromTextureAsset. Write the enumerator name — [SamplerSource="Wrap_WorldGroupSettings"]; SSM_Wrap_WorldGroupSettings is accepted with DSH5278. The display names Shared: Wrap and Shared: Clamp normalize to nothing in the catalog and are DSH5215 (since 2.0.0; 1.x accepted them).

Related texture-sample keys

These are the keys the decompiler emits on every texture-sample parameter, with the value it treats as the default. All are ordinary reflected metadata.

MipValueMode is the one key that changes the node's pin names, and therefore which names the call form can match on the live node.

Dimension validation and inference

SamplerType describes interpretation; the texture's dimension is a separate check.

TextureObjectParameter's dimension is read off the asset its default loads: UTextureCube → TextureCube, UTexture2DArray → Texture2DArray, UVolumeTexture → VolumeTexture, anything else — or a default that does not load — Texture2D.

[!WARNING] A TextureSampleParameterCube pointed at a 2D texture by its plain object path generates cleanly and fails later inside Unreal's shader compiler. See Parameter node tokens.

Diagnostics

Example

Shader(Name="Docs/M_SamplerType")
{
    Properties = {
        // Explicit: linear data, shared sampler, no slot consumed.
        TextureSampleParameter2D MaskMap = Path(Game, "Textures/T_Mask") [
            SamplerType   = "LinearColor";
            SamplerSource = "Wrap_WorldGroupSettings";
            MipValueMode  = "None";
        ];

        // Inferred: SamplerType follows the asset's compression settings.
        TextureSampleParameter2D BaseMap = Path(Game, "Textures/T_Base");

        // A 1.x spelling: accepted, with DSH5278.
        TextureSampleParameterCube Env = Path(Engine, "EngineResources/DefaultTextureCube") [
            SamplerType = "linear color"
        ];

        const Texture2D Lut = Path(Game, "Textures/T_Lut") [SamplerType = "Data"];
    }

    Settings = { Domain = "Surface"; ShadingModel = "DefaultLit"; BlendMode = "Opaque"; }
    Outputs  = { vec3 Color; Base.BaseColor = Color; }

    Graph = {
        vec2 UV = UE.TexCoord(Index = 0);
        vec4 B  = BaseMap(Coordinates = UV);
        vec4 M  = MaskMap(Coordinates = UV);
        Color = B.rgb * M.r;
    }
}

Applied values:

MaskMap  SamplerType = SAMPLERTYPE_LinearColor  SamplerSource = SSM_Wrap_WorldGroupSettings
BaseMap  SamplerType = <AutoSetSampleType from /Game/Textures/T_Base>
Env      SamplerType = SAMPLERTYPE_LinearColor  ("linear color" normalizes to LinearColor; DSH5278)
Lut      SamplerType = SAMPLERTYPE_Data         on a TextureObject (const) node

Env and Lut are applied when a body reads them; this Graph does not, so they build nothing.

See also

• Parameters — the hub and the decision table
• Metadata block — the enum-literal rules this key follows
• Parameter node tokens — which tokens expose SamplerType at all
• Compact type tokens — the five compact texture tokens and their fallback assets
• Path(…) — the asset-reference grammar
• Using parameters in Graph — how MipValueMode changes the callable pin names
• Decompiler — the round-trip guarantee for these keys