Material

What is Material API

The Material API is a structure to define the surface properties of what you're drawing as described by traditional PBR shading models.

It does nothing on it's own but it's a contract on how the material would react to lighting, Shading Models consume what comes from it.

API Reference

class Material
{
    float3 Albedo;
    float  Metalness;
    float  Roughness;
    float3 Emission;
    float3 Normal; // World-space normals
    float  TintMask;
    float  AmbientOcclusion;
    float3 Transmission;
    float Opacity;

    // This stuff is part of what describes a surface too and needed for lighting
    float3 WorldPosition;           // vPositionWs (vPositionWithOffsetWs + g_vHighPrecisionLightingOffsetWs.xyz)           
	float3 WorldPositionWithOffset; // vPositionWithOffsetWs in PixelInput
    float4 ScreenPosition;          // vPositionSs in PixelInput

    // baked lighting and/or anisotropic lighting
    float3 TangentNormal;
    float3 WorldTangentU; // vTangentUWs in PixelInput
    float3 WorldTangentV; // vTangentVWs in PixelInput
    float2 LightmapUV; // if D_BAKED_LIGHTING_FROM_LIGHTMAP is enabled

    float2 TextureCoords; // required for ToolsVis
};

Helper Functions

• To initialize an empty material you can use Material::Init( PixelInput i ) and fill up the needed fields for the Shading Model
• If you are initializing the material in a shader that does not use built-in pixel input struct, but still utilizes standard shading model, you should use Material::Init( float3 RelativeWorldPosition, float4 ScreenPosition ). It will automatically setup a material with world/screen coordinate data which is necessary for the shading model.
• Material::lerp( Material a, Material b, float Amount ) allows to lerp between two materials, works the same way as HLSL's lerp() function.

Legacy Behavior

While this method is still working and compiles normally, it is recommended to use Material::Init( PixelInput i ) instead.

• Material::From( PixelInput i ) can be used to process the standard input and automatically expose all common PBR texture inputs to Material Editor. All these texture inputs will be automatically sampled and inserted into initialized material as well. You must add #include Material.CommonInputs.hlsl in your pixel shader code for this to work correctly. If you need more control over inputs, use different ways to initialize a new material.