Add backwards compatibility function for materials (o3de#18076)

Signed-off-by: Akio Gaule <[email protected]>

Author: akioCL

Gems/Atom/Feature/Common/Assets/Shaders/Materials/BasePBR/BasePBR_SurfaceEval.azsli

@@ -8,6 +8,10 @@
 
 #pragma once
 
+#ifndef ENABLE_VERTEX_COLOR
+#define ENABLE_VERTEX_COLOR 0
+#endif
+
 // This #define magic lets you use the EvaluateSurface function in this file without making it the final EvaluateSurface
 // used in your shader. Simply #define EvaluateSurface to your custom definition before including this file
 //
@@ -17,6 +21,18 @@
 
 #include <Atom/Features/MatrixUtility.azsli>
 
+real3 BlendVertexColor(real3 baseColor, real3 vertexColor)
+{
+#if ENABLE_VERTEX_COLOR
+    // Check to ensure the material is using vertex colors (i.e o_useVertexColor) and that the mesh supports color vertex stream (i.e o_color0_isBound)
+    if(o_useVertexColor && o_color0_isBound)
+    {
+        baseColor = BlendBaseColor(vertexColor, baseColor, real(MaterialSrg::m_vertexColorFactor), o_vertexColorBlendMode, true);
+    }
+#endif
+    return baseColor;
+}
+
 Surface EvaluateSurface_BasePBR(
     float3 positionWS,
     real3 vertexNormal,
@@ -53,11 +69,7 @@ Surface EvaluateSurface_BasePBR(
     float2 baseColorUv = uvs[MaterialSrg::m_baseColorMapUvIndex];
     real3 sampledColor = GetBaseColorInput(MaterialSrg::m_baseColorMap, MaterialSrg::m_sampler, baseColorUv, real3(MaterialSrg::m_baseColor.rgb), o_baseColor_useTexture, uvDxDy, customDerivatives);
     real3 baseColor = BlendBaseColor(sampledColor, real3(MaterialSrg::m_baseColor.rgb), real(MaterialSrg::m_baseColorFactor), o_baseColorTextureBlendMode, o_baseColor_useTexture);
-    // Check to ensure the material is using vertex colors (i.e o_useVertexColor) and that the mesh supports color vertex stream (i.e o_color0_isBound)
-    if(o_useVertexColor && o_color0_isBound)
-    {
-        baseColor = BlendBaseColor(real3(vertexColor.rgb), baseColor, real(MaterialSrg::m_vertexColorFactor), o_vertexColorBlendMode, true);
-    }
+    baseColor = BlendVertexColor(baseColor, real3(vertexColor.rgb));
 
     // ------- Metallic -------
 
@@ -81,8 +93,39 @@ Surface EvaluateSurface_BasePBR(
     return surface;
 }
 
+float4 GetVertexColor(VsOutput IN)
+{
+#if ENABLE_VERTEX_COLOR
+    return IN.color0;
+#else
+    return float4(1.0f, 1.0f, 1.0f, 1.0f);
+#endif
+}
+
 // helper function to keep compatible with the previous version
 // because dxc compiler doesn't allow default parameters on functions with overloads
+Surface EvaluateSurface_BasePBR(
+    float3 positionWS,
+    real3 vertexNormal,
+    float3 tangents[UvSetCount],
+    float3 bitangents[UvSetCount],
+    float2 uvs[UvSetCount],
+    bool isFrontFace,
+    float4 uvDxDy,
+    bool customDerivatives)
+{
+    return EvaluateSurface_BasePBR(
+        positionWS,
+        vertexNormal,
+        tangents,
+        bitangents,
+        uvs,
+        isFrontFace,
+        uvDxDy,
+        customDerivatives,
+        float4(1.0f, 1.0f, 1.0f, 1.0f));
+}
+
 Surface EvaluateSurface_BasePBR(
     float3 positionWS,
     real3 vertexNormal,
@@ -99,8 +142,7 @@ Surface EvaluateSurface_BasePBR(
         uvs,
         isFrontFace,
         float4(0.0f, 0.0f, 0.0f, 0.0f),
-        false,
-        float4(1.0f, 1.0f, 1.0f, 1.0f));
+        false);
 }
 
 Surface EvaluateSurface_BasePBR(VsOutput IN, PixelGeometryData geoData, float4 uvDxDy, bool customDerivatives)
@@ -114,7 +156,7 @@ Surface EvaluateSurface_BasePBR(VsOutput IN, PixelGeometryData geoData, float4 u
         geoData.isFrontFace,
         uvDxDy,
         customDerivatives,
-        IN.color0);
+        GetVertexColor(IN));
 }
 
 Surface EvaluateSurface_BasePBR(VsOutput IN, PixelGeometryData geoData)
@@ -128,5 +170,5 @@ Surface EvaluateSurface_BasePBR(VsOutput IN, PixelGeometryData geoData)
         geoData.isFrontFace,
         float4(0.0f, 0.0f, 0.0f, 0.0f),
         false,
-        IN.color0);
+        GetVertexColor(IN));
 }

Gems/Atom/Feature/Common/Assets/Shaders/Materials/BasePBR/BasePBR_VertexData.azsli

@@ -27,7 +27,6 @@
 #define ENABLE_VERTEX_COLOR 0
 #endif
 
-
 #if ENABLE_VERTEX_COLOR
 option bool o_color0_isBound = false;
 #endif

Gems/Atom/Feature/Common/Assets/Shaders/Materials/BasePBR/BasePBR_VertexEval.azsli

@@ -8,6 +8,10 @@
 
 #pragma once
 
+#ifndef ENABLE_VERTEX_COLOR
+#define ENABLE_VERTEX_COLOR 0
+#endif
+
 // This #define magic allows you to use the EvaluateVertexGeometry function in this file without making it the final
 // EvaluateVertexGeometry used in your shader. Simply #define EvaluateVertexGeometry before including this file
 //
@@ -25,9 +29,9 @@ VsOutput EvaluateVertexGeometry_BasePBR(
     float4 tangent,
     float2 uv0,
     float2 uv1,
-    float4 color0,
     uint instanceId,
-    bool useVertexColor0)
+    bool useVertexColor0,
+    float4 color0)
 {
     VsOutput output;
 
@@ -61,22 +65,49 @@ VsOutput EvaluateVertexGeometry_BasePBR(
     return output;
 }
 
-VsOutput EvaluateVertexGeometry_BasePBR(VsInput IN, VsSystemValues SV)
+void GetVertexColor(VsInput IN, out float4 color, out bool useVertexColor)
 {
 #if ENABLE_VERTEX_COLOR
-    float4 color0 = IN.m_optional_color0;
-    bool useVertexColor0 = o_color0_isBound;
+    color = IN.m_optional_color0;
+    useVertexColor = o_color0_isBound;
 #else
-    float4 color0 = float4(1.0f, 1.0f, 1.0f, 1.0f);
-    bool useVertexColor0 = false;
+    color = float4(1.0f, 1.0f, 1.0f, 1.0f);
+    useVertexColor = false;
 #endif
+}
+
+VsOutput EvaluateVertexGeometry_BasePBR(VsInput IN, VsSystemValues SV)
+{
+    float4 color0;
+    bool useVertexColor0;
+    GetVertexColor(IN, color0, useVertexColor0);
+
     return EvaluateVertexGeometry_BasePBR(
         IN.position,
         IN.normal,
         IN.tangent,
         IN.uv0,
         IN.uv1,
-        color0,
         SV.m_instanceId,
-        useVertexColor0);
+        useVertexColor0,
+        color0);
+}
+
+VsOutput EvaluateVertexGeometry_BasePBR(
+    float3 position,
+    float3 normal,
+    float4 tangent,
+    float2 uv0,
+    float2 uv1,
+    uint instanceId)
+{
+    return EvaluateVertexGeometry_BasePBR(
+        position,
+        normal,
+        tangent,
+        uv0,
+        uv1,
+        instanceId,
+        float4(1.0f, 1.0f, 1.0f, 1.0f),
+        false);
 }

Gems/Atom/Feature/Common/Assets/Shaders/Materials/EnhancedPBR/EnhancedPBR_SurfaceEval.azsli

@@ -28,7 +28,8 @@ Surface EvaluateSurface_EnhancedPBR(
     bool isFrontFace,
     bool isDisplacementClipped,
     float4 uvDxDy,
-    bool customDerivatives)
+    bool customDerivatives,
+    float4 vertexColor)
 {
     Surface surface;
     surface.position = positionWS;
@@ -73,6 +74,7 @@ Surface EvaluateSurface_EnhancedPBR(
     real3 baseColor = GetDetailedBaseColorInput(
         MaterialSrg::m_baseColorMap,             MaterialSrg::m_sampler, baseColorUv, o_baseColor_useTexture,        real3(MaterialSrg::m_baseColor),  real(MaterialSrg::m_baseColorFactor), o_baseColorTextureBlendMode,
         MaterialSrg::m_detail_baseColor_texture, MaterialSrg::m_sampler, detailUv,    o_detail_baseColor_useTexture, detailLayerBaseColorFactor, uvDxDy, customDerivatives);
+    baseColor = BlendVertexColor(baseColor, real3(vertexColor.rgb));
 
     // ------- Parallax Clipping -------
 
@@ -175,8 +177,34 @@ Surface EvaluateSurface_EnhancedPBR(
     return surface;
 }
 
-// helper function to keep compatible with the previous version
+// Helper functions to keep compatible with the previous version
 // because dxc compiler doesn't allow default parameters on functions with overloads
+Surface EvaluateSurface_EnhancedPBR(
+    float3 positionWS,
+    real3 normalWS,
+    float3 tangents[UvSetCount],
+    float3 bitangents[UvSetCount],
+    float2 uvs[UvSetCount],
+    float2 detailUvs[UvSetCount],
+    bool isFrontFace,
+    bool isDisplacementClipped,
+    float4 uvDxDy,
+    bool customDerivatives)
+{
+    return EvaluateSurface_EnhancedPBR(
+            positionWS,
+            normalWS,
+            tangents,
+            bitangents,
+            uvs,
+            detailUvs,
+            isFrontFace,
+            isDisplacementClipped,
+            uvDxDy,
+            customDerivatives,
+            float4(1.0f, 1.0f, 1.0f, 1.0f));
+}
+
 Surface EvaluateSurface_EnhancedPBR(
     float3 positionWS,
     real3 normalWS,
@@ -212,7 +240,8 @@ Surface EvaluateSurface_EnhancedPBR(VsOutput IN, PixelGeometryData geoData, floa
         geoData.isFrontFace,
         geoData.isDisplacementClipped,
         uvDxDy,
-        customDerivatives);
+        customDerivatives,
+        GetVertexColor(IN));
 }
 
 Surface EvaluateSurface_EnhancedPBR(VsOutput IN, PixelGeometryData geoData)
@@ -227,5 +256,6 @@ Surface EvaluateSurface_EnhancedPBR(VsOutput IN, PixelGeometryData geoData)
         geoData.isFrontFace,
         geoData.isDisplacementClipped,
         float4(0.0f, 0.0f, 0.0f, 0.0f),
-        false);
+        false,
+        GetVertexColor(IN));
 }

Gems/Atom/Feature/Common/Assets/Shaders/Materials/EnhancedPBR/EnhancedPBR_VertexData.azsli

@@ -8,6 +8,10 @@
 
 #pragma once
 
+#ifndef ENABLE_VERTEX_COLOR
+#define ENABLE_VERTEX_COLOR 0
+#endif
+
 #ifndef VsOutput
 #define VsOutput        VsOutput_EnhancedPBR
 #endif
@@ -39,8 +43,10 @@
         float2 uvs[UvSetCount] : UV1;
         float2 detailUvs[UvSetCount] : UV3;
 
+#if ENABLE_VERTEX_COLOR
         // Optional
         float4 color0 : UV7; // Using UV7 just to leave some room for non optional attributes
+#endif
     };
 
 #endif

Gems/Atom/Feature/Common/Assets/Shaders/Materials/EnhancedPBR/EnhancedPBR_VertexEval.azsli

@@ -25,10 +25,11 @@ VsOutput EvaluateVertexGeometry_EnhancedPBR(
     float2 uv0,
     float2 uv1,
     uint instanceId,
+    bool useVertexColor,
     float4 color0)
 {
     // BasePBRP
-    VsOutput output = EvaluateVertexGeometry_BasePBR(position, normal, tangent, uv0, uv1, color0, instanceId, o_color0_isBound);
+    VsOutput output = EvaluateVertexGeometry_BasePBR(position, normal, tangent, uv0, uv1, instanceId, useVertexColor, color0);
 
     // Detail UVs
     float2 detailUvs[UvSetCount] = { uv0, uv1 };
@@ -37,14 +38,40 @@ VsOutput EvaluateVertexGeometry_EnhancedPBR(
     return output;
 }
 
+// Helper functions to keep compatible with the previous version
+// because dxc compiler doesn't allow default parameters on functions with overloads
 VsOutput EvaluateVertexGeometry_EnhancedPBR(VsInput IN, VsSystemValues SV)
 {
+    float4 color0;
+    bool useVertexColor0;
+    GetVertexColor(IN, color0, useVertexColor0);
+
     return EvaluateVertexGeometry_EnhancedPBR(
         IN.position,
         IN.normal,
         IN.tangent,
         IN.uv0,
         IN.uv1,
         SV.m_instanceId,
-        IN.m_optional_color0);
+        useVertexColor0,
+        color0);
+}
+
+VsOutput EvaluateVertexGeometry_EnhancedPBR(
+    float3 position,
+    float3 normal,
+    float4 tangent,
+    float2 uv0,
+    float2 uv1,
+    uint instanceId)
+{
+    return EvaluateVertexGeometry_EnhancedPBR(
+        position,
+        normal,
+        tangent,
+        uv0,
+        uv1,
+        instanceId,
+        false,
+        float4(1.0f, 1.0f, 1.0f, 1.0f));
 }