Merge pull request #90 from Unity-Technologies/Branch_fix_height_amplitude

Fixed previous CL for height scale bias handling. Shader code is not the same as what is shown in the interface (was causing weird GUI behavior)

Assets/ScriptableRenderLoop/HDRenderPipeline/Material/LayeredLit/LayeredLit.shader

         _HeightMap2("HeightMap2", 2D) = "black" {}
         _HeightMap3("HeightMap3", 2D) = "black" {}
 
-        _HeightScale0("Height Scale0", Float) = 1
-        _HeightScale1("Height Scale1", Float) = 1
-        _HeightScale2("Height Scale2", Float) = 1
-        _HeightScale3("Height Scale3", Float) = 1
+        _HeightAmplitude0("Height Scale0", Float) = 1
+        _HeightAmplitude1("Height Scale1", Float) = 1
+        _HeightAmplitude2("Height Scale2", Float) = 1
+        _HeightAmplitude3("Height Scale3", Float) = 1
-        _HeightBias0("Height Bias0", Float) = 0
-        _HeightBias1("Height Bias1", Float) = 0
-        _HeightBias2("Height Bias2", Float) = 0
-        _HeightBias3("Height Bias3", Float) = 0
+        _HeightCenter0("Height Bias0", Float) = 0
+        _HeightCenter1("Height Bias1", Float) = 0
+        _HeightCenter2("Height Bias2", Float) = 0
+        _HeightCenter3("Height Bias3", Float) = 0
 
         _DetailMap0("DetailMap0", 2D) = "black" {}
         _DetailMap1("DetailMap1", 2D) = "black" {}
         _HeightFactor2("_HeightFactor2", Range(0, 5)) = 1
         _HeightFactor3("_HeightFactor3", Range(0, 5)) = 1
 
-        _BlendSize1("_BlendSize1", Range(0, 0.05)) = 0.0
-        _BlendSize2("_BlendSize2", Range(0, 0.05)) = 0.0
-        _BlendSize3("_BlendSize3", Range(0, 0.05)) = 0.0
+        _BlendSize1("_BlendSize1", Range(0, 0.30)) = 0.0
+        _BlendSize2("_BlendSize2", Range(0, 0.30)) = 0.0
+        _BlendSize3("_BlendSize3", Range(0, 0.30)) = 0.0
 
         _InheritBaseLayer1("_InheritBaseLayer1", Range(0, 1.0)) = 0.0
         _InheritBaseLayer2("_InheritBaseLayer2", Range(0, 1.0)) = 0.0

Assets/ScriptableRenderLoop/HDRenderPipeline/Material/Lit/Editor/LitUI.cs

         protected const string kNormalScale = "_NormalScale";
         protected MaterialProperty heightMap = null;
         protected const string kHeightMap = "_HeightMap";
-        protected MaterialProperty heightScale = null;
-        protected const string kHeightScale = "_HeightScale";
-        protected MaterialProperty heightBias = null;
-        protected const string kHeightBias= "_HeightBias";
+        protected MaterialProperty heightAmplitude = null;
+        protected const string kHeightAmplitude = "_HeightAmplitude";
+        protected MaterialProperty heightCenter = null;
+        protected const string kHeightCenter = "_HeightCenter";
         protected MaterialProperty tangentMap = null;
         protected const string kTangentMap = "_TangentMap";
         protected MaterialProperty anisotropy = null;
             normalMap = FindProperty(kNormalMap, props);
             normalScale = FindProperty(kNormalScale, props);           
             heightMap = FindProperty(kHeightMap, props);
-            heightScale = FindProperty(kHeightScale, props);
-            heightBias = FindProperty(kHeightBias, props);
+            heightAmplitude = FindProperty(kHeightAmplitude, props);
+            heightCenter = FindProperty(kHeightCenter, props);
             tangentMap = FindProperty(kTangentMap, props);
             anisotropy = FindProperty(kAnisotropy, props);
             anisotropyMap = FindProperty(kAnisotropyMap, props);
             m_MaterialEditor.TexturePropertySingleLine(Styles.heightMapText, heightMap);
             if(!heightMap.hasMixedValue && heightMap.textureValue != null)
             {
-                // Be careful, the scale and bias here is different from the one shader properties
-                // In the shader values are in world units and the formula is finalHeight = height * scale + bias
-                // In the GUI it's (height - center) * amplitude
-                float amplitude = heightScale.floatValue;
-                float center = -heightBias.floatValue / amplitude;
-                // Scale = Amplitude so no need for special handling
-                m_MaterialEditor.ShaderProperty(heightScale, Styles.heightMapAmplitudeText);
-
-                EditorGUI.showMixedValue = heightScale.hasMixedValue;
-                EditorGUI.BeginChangeCheck();
-                float newCenter = EditorGUILayout.FloatField(Styles.heightMapCenterText, center);
-                if(EditorGUI.EndChangeCheck())
-                {
-                    heightBias.floatValue = -newCenter * amplitude;
-                }
+                m_MaterialEditor.ShaderProperty(heightAmplitude, Styles.heightMapAmplitudeText);
+                m_MaterialEditor.ShaderProperty(heightCenter, Styles.heightMapCenterText);
                 EditorGUI.showMixedValue = false;
                 EditorGUI.indentLevel--;
             }

Assets/ScriptableRenderLoop/HDRenderPipeline/Material/Lit/Lit.shader

         _NormalMap("NormalMap", 2D) = "bump" {}
         _NormalScale("_NormalScale", Range(0.0, 2.0)) = 1
 
-        // Be careful, the scale and bias here is different from the one shown in the GUI
-        // Here both value are in world units and the formula is finalHeight = height * scale + bias
-        // In the GUI it's (height - center) * amplitude
-        _HeightScale("Height Scale", Float) = 0.01
-        _HeightBias("Height Bias", Float) = -0.005
+        _HeightAmplitude("Height Amplitude", Float) = 0.01 // In world units
+        _HeightCenter("Height Center", Float) = 0.5 // In texture space
 
         _TangentMap("TangentMap", 2D) = "bump" {}
         _Anisotropy("Anisotropy", Range(0.0, 1.0)) = 0

Assets/ScriptableRenderLoop/HDRenderPipeline/Material/Lit/LitData.hlsl

 {
     float finalLayerHeight = heightFactor * layerHeight + heightOffset + _VertexColorHeightFactor * (vertexColor * 2.0 - 1.0);
 
-    edgeBlendStrength = max(0.001, edgeBlendStrength);
-
-    float heightThreshold = previousLayerHeight + edgeBlendStrength;
+    edgeBlendStrength = max(0.00001, edgeBlendStrength);
 
     if (previousLayerHeight >= finalLayerHeight)
     {

Assets/ScriptableRenderLoop/HDRenderPipeline/Material/Lit/LitProperties.hlsl

 TEXTURE2D(_HeightMap);
 SAMPLER2D(sampler_HeightMap);
 
-float _HeightScale;
-float _HeightBias;
+float _HeightAmplitude;
+float _HeightCenter;
 
 TEXTURE2D(_TangentMap);
 SAMPLER2D(sampler_TangentMap);
 PROP_DECL(float, _DetailHeightScale);
 PROP_DECL(float, _DetailAOScale);
 
-PROP_DECL(float, _HeightScale);
-PROP_DECL(float, _HeightBias);
+PROP_DECL(float, _HeightAmplitude);
+PROP_DECL(float, _HeightCenter);
 
 TEXTURE2D(_DiffuseLightingMap);
 SAMPLER2D(sampler_DiffuseLightingMap);

Assets/ScriptableRenderLoop/HDRenderPipeline/Material/Lit/LitSurfaceData.hlsl

     float height = 0.0f;
 
 #ifdef _HEIGHTMAP
-    height = SAMPLE_LAYER_TEXTURE2D(ADD_IDX(_HeightMap), ADD_ZERO_IDX(sampler_HeightMap), ADD_IDX(layerTexCoord.base)).r * ADD_IDX(_HeightScale) + ADD_IDX(_HeightBias);
+    height = (SAMPLE_LAYER_TEXTURE2D(ADD_IDX(_HeightMap), ADD_ZERO_IDX(sampler_HeightMap), ADD_IDX(layerTexCoord.base)).r - ADD_IDX(_HeightCenter)) * ADD_IDX(_HeightAmplitude);
 
    //#ifndef _HEIGHTMAP_AS_DISPLACEMENT
    // //height = SAMPLE_LAYER_TEXTURE2D(ADD_IDX(_HeightMap), ADD_ZERO_IDX(sampler_HeightMap), ADD_IDX(layerTexCoord.base)).r * ADD_IDX(_HeightScale) + ADD_IDX(_HeightBias);