Merge pull request #719 from rextimmy/dxtnm-parallax-fix

Fix to allow parallax mapping with dxtnm textures via the red channel.

Engine/source/materials/processedShaderMaterial.cpp

@@ -396,11 +396,9 @@ void ProcessedShaderMaterial::_determineFeatures(  U32 stageNum,
    // cannot do on SM 2.0 and below.
    if ( shaderVersion > 2.0f )
    {
-      // Only allow parallax if we have a normal map and
-      // we're not using DXTnm compression.
+
       if (  mMaterial->mParallaxScale[stageNum] > 0.0f &&
-         fd.features[ MFT_NormalMap ] &&
-         !fd.features[ MFT_IsDXTnm ] )
+         fd.features[ MFT_NormalMap ] )
          fd.features.addFeature( MFT_Parallax );
 
       // If not parallax then allow per-pixel specular if

Engine/source/shaderGen/HLSL/bumpHLSL.cpp

@@ -347,8 +347,16 @@ void ParallaxFeatHLSL::processPix(  Vector<ShaderComponent*> &componentList,
    Var *normalMap = getNormalMapTex();
 
    // Call the library function to do the rest.
-   meta->addStatement( new GenOp( "   @.xy += parallaxOffset( @, @.xy, @, @ );\r\n", 
-      texCoord, normalMap, texCoord, negViewTS, parallaxInfo ) );
+   if(fd.features.hasFeature( MFT_IsDXTnm, getProcessIndex() ))
+   {
+      meta->addStatement( new GenOp( "   @.xy += parallaxOffsetDxtnm( @, @.xy, @, @ );\r\n", 
+         texCoord, normalMap, texCoord, negViewTS, parallaxInfo ) );
+   }
+   else
+   {
+      meta->addStatement( new GenOp( "   @.xy += parallaxOffset( @, @.xy, @, @ );\r\n", 
+         texCoord, normalMap, texCoord, negViewTS, parallaxInfo ) );
+   }
 
    // TODO: Fix second UV maybe?
 

Engine/source/terrain/hlsl/terrFeatureHLSL.cpp

@@ -468,8 +468,16 @@ void TerrainDetailMapFeatHLSL::processPix(   Vector<ShaderComponent*> &component
       Var *normalMap = _getNormalMapTex();
 
       // Call the library function to do the rest.
-      meta->addStatement( new GenOp( "   @.xy += parallaxOffset( @, @.xy, @, @.z * @ );\r\n", 
-         inDet, normalMap, inDet, negViewTS, detailInfo, detailBlend ) );
+      if(fd.features.hasFeature( MFT_IsDXTnm, detailIndex ) )
+      {
+         meta->addStatement( new GenOp( "   @.xy += parallaxOffsetDxtnm( @, @.xy, @, @.z * @ );\r\n", 
+            inDet, normalMap, inDet, negViewTS, detailInfo, detailBlend ) );
+      }
+      else
+      {
+         meta->addStatement( new GenOp( "   @.xy += parallaxOffset( @, @.xy, @, @.z * @ );\r\n", 
+            inDet, normalMap, inDet, negViewTS, detailInfo, detailBlend ) );
+      }
    }
 
    // If this is a prepass then we skip color.

Templates/Empty/game/shaders/common/torque.hlsl

@@ -151,6 +151,21 @@ float2 parallaxOffset( sampler2D texMap, float2 texCoord, float3 negViewTS, floa
    return offset;
 }
 
+/// Same as parallaxOffset but for dxtnm where depth is stored in the red channel instead of the alpha
+float2 parallaxOffsetDxtnm(sampler2D texMap, float2 texCoord, float3 negViewTS, float depthScale)
+{
+   float depth = tex2D(texMap, texCoord).r;
+   float2 offset = negViewTS.xy * (depth * depthScale);
+
+   for (int i = 0; i < PARALLAX_REFINE_STEPS; i++)
+   {
+      depth = (depth + tex2D(texMap, texCoord + offset).r) * 0.5;
+      offset = negViewTS.xy * (depth * depthScale);
+   }
+
+   return offset;
+}
+
 
 /// The maximum value for 16bit per component integer HDR encoding.
 static const float HDR_RGB16_MAX = 100.0;

Templates/Full/game/shaders/common/torque.hlsl

@@ -151,6 +151,21 @@ float2 parallaxOffset( sampler2D texMap, float2 texCoord, float3 negViewTS, floa
    return offset;
 }
 
+/// Same as parallaxOffset but for dxtnm where depth is stored in the red channel instead of the alpha
+float2 parallaxOffsetDxtnm(sampler2D texMap, float2 texCoord, float3 negViewTS, float depthScale)
+{
+   float depth = tex2D(texMap, texCoord).r;
+   float2 offset = negViewTS.xy * (depth * depthScale);
+
+   for (int i = 0; i < PARALLAX_REFINE_STEPS; i++)
+   {
+      depth = (depth + tex2D(texMap, texCoord + offset).r) * 0.5;
+      offset = negViewTS.xy * (depth * depthScale);
+   }
+
+   return offset;
+}
+
 
 /// The maximum value for 16bit per component integer HDR encoding.
 static const float HDR_RGB16_MAX = 100.0;