Terrain macro material fixes (#5182)

* Minor fixes for macro materials
- When macro image views are no longer used, they will explicitely be set to nullptr
- limiting for loop in shader to the number of macro materials total so it doesn't read unitialized memory

Signed-off-by: Ken Pruiksma <pruiksma@amazon.com>

* Removing parts of the terrain shader no longer used.

Signed-off-by: Ken Pruiksma <pruiksma@amazon.com>

* Fixing normalization in shaders, adding default valus for all structs used in SRGs.

Signed-off-by: Ken Pruiksma <pruiksma@amazon.com>

Gems/Terrain/Assets/Shaders/Terrain/TerrainPBR_ForwardPass.azsl

@@ -22,11 +22,9 @@ struct VSOutput
 {
     float4 m_position : SV_Position;
     float3 m_normal: NORMAL;
-    float3 m_tangent : TANGENT; 
-    float3 m_bitangent : BITANGENT; 
     float3 m_worldPosition : UV0;
-    float3 m_shadowCoords[ViewSrg::MaxCascadeCount] : UV2;
     float2 m_uv : UV1;
+    float3 m_shadowCoords[ViewSrg::MaxCascadeCount] : UV2;
 };
 
 VSOutput TerrainPBR_MainPassVS(VertexInput IN)
@@ -47,9 +45,9 @@ VSOutput TerrainPBR_MainPassVS(VertexInput IN)
     float down  = GetHeight(origUv + terrainData.m_uvStep * float2( 0.0f,  1.0f));
     float left  = GetHeight(origUv + terrainData.m_uvStep * float2(-1.0f,  0.0f));
 
-    OUT.m_bitangent = normalize(float3(0.0, terrainData.m_sampleSpacing * 2.0f, down - up));
-    OUT.m_tangent = normalize(float3(terrainData.m_sampleSpacing * 2.0f, 0.0, right - left));
-    OUT.m_normal = cross(OUT.m_tangent, OUT.m_bitangent);
+    float3 bitangent = normalize(float3(0.0, terrainData.m_sampleSpacing * 2.0f, down - up));
+    float3 tangent = normalize(float3(terrainData.m_sampleSpacing * 2.0f, 0.0, right - left));
+    OUT.m_normal = normalize(cross(tangent, bitangent));
     OUT.m_uv = uv;
 
     // directional light shadow 
@@ -75,18 +73,14 @@ ForwardPassOutput TerrainPBR_MainPassPS(VSOutput IN)
     surface.position = IN.m_worldPosition.xyz;
     float viewDistance = length(ViewSrg::m_worldPosition - surface.position);
     float detailFactor = saturate((viewDistance - TerrainMaterialSrg::m_detailFadeDistance) / max(TerrainMaterialSrg::m_detailFadeLength, EPSILON));
-
-    ObjectSrg::TerrainData terrainData = ObjectSrg::m_terrainData;
-    float2 origUv = lerp(terrainData.m_uvMin, terrainData.m_uvMax, IN.m_uv);
-    origUv.y = 1.0 - origUv.y;
     float2 detailUv = IN.m_uv * TerrainMaterialSrg::m_detailTextureMultiplier;
     
     // ------- Normal -------
-    float3 macroNormal = IN.m_normal;
+    float3 macroNormal = normalize(IN.m_normal);
     
     // ------- Macro Color / Normal -------
     float3 macroColor = TerrainMaterialSrg::m_baseColor.rgb;
-    [unroll] for (uint i = 0; i < 4; ++i)
+    [unroll] for (uint i = 0; i < 4 && (i < ObjectSrg::m_macroMaterialCount); ++i)
     {
         float2 macroUvMin = ObjectSrg::m_macroMaterialData[i].m_uvMin;
         float2 macroUvMax = ObjectSrg::m_macroMaterialData[i].m_uvMax;

Gems/Terrain/Code/Source/TerrainRenderer/Components/TerrainMacroMaterialComponent.cpp

@@ -248,6 +248,7 @@ namespace Terrain
         {
             m_configuration.m_macroColorAsset = asset;
             m_colorImage = AZ::RPI::StreamingImage::FindOrCreate(m_configuration.m_macroColorAsset);
+            m_colorImage->GetRHIImage()->SetName(AZ::Name(m_configuration.m_macroColorAsset.GetHint()));
 
             // Clear the texture asset reference to make sure we don't prevent hot-reloading.
             m_configuration.m_macroColorAsset.Release();
@@ -256,6 +257,7 @@ namespace Terrain
         {
             m_configuration.m_macroNormalAsset = asset;
             m_normalImage = AZ::RPI::StreamingImage::FindOrCreate(m_configuration.m_macroNormalAsset);
+            m_normalImage->GetRHIImage()->SetName(AZ::Name(m_configuration.m_macroNormalAsset.GetHint()));
 
             // Clear the texture asset reference to make sure we don't prevent hot-reloading.
             m_configuration.m_macroColorAsset.Release();

Gems/Terrain/Code/Source/TerrainRenderer/TerrainFeatureProcessor.cpp

@@ -535,7 +535,9 @@ namespace Terrain
                     sectorData.m_srg->SetConstant(m_terrainDataIndex, terrainDataForSrg);
 
                     AZStd::array<ShaderMacroMaterialData, MaxMaterialsPerSector> macroMaterialData;
-                    for (uint32_t i = 0; i < sectorData.m_macroMaterials.size(); ++i)
+
+                    uint32_t i = 0;
+                    for (; i < sectorData.m_macroMaterials.size(); ++i)
                     {
                         const MacroMaterialData& materialData = m_macroMaterials.GetData(sectorData.m_macroMaterials.at(i));
                         ShaderMacroMaterialData& shaderData = macroMaterialData.at(i);
@@ -564,6 +566,11 @@ namespace Terrain
                         // set flags for which images are used.
                         shaderData.m_mapsInUse = (colorImageView ? ColorImageUsed : 0) | (normalImageView ? NormalImageUsed : 0);
                     }
+                    for (; i < sectorData.m_macroMaterials.capacity(); ++i)
+                    {
+                        sectorData.m_srg->SetImageView(m_macroColorMapIndex, nullptr, i);
+                        sectorData.m_srg->SetImageView(m_macroNormalMapIndex, nullptr, i);
+                    }
 
                     sectorData.m_srg->SetConstantArray(m_macroMaterialDataIndex, macroMaterialData);
                     sectorData.m_srg->SetConstant(m_macroMaterialCountIndex, aznumeric_cast<uint32_t>(sectorData.m_macroMaterials.size()));

Gems/Terrain/Code/Source/TerrainRenderer/TerrainFeatureProcessor.h

@@ -68,18 +68,18 @@ namespace Terrain
 
         struct ShaderTerrainData // Must align with struct in Object Srg
         {
-            AZStd::array<float, 2> m_uvMin;
-            AZStd::array<float, 2> m_uvMax;
-            AZStd::array<float, 2> m_uvStep;
-            float m_sampleSpacing;
-            float m_heightScale;
+            AZStd::array<float, 2> m_uvMin{ 0.0f, 0.0f };
+            AZStd::array<float, 2> m_uvMax{ 1.0f, 1.0f };
+            AZStd::array<float, 2> m_uvStep{ 1.0f, 1.0f };
+            float m_sampleSpacing{ 1.0f };
+            float m_heightScale{ 1.0f };
         };
 
-        struct ShaderMacroMaterialData
+        struct ShaderMacroMaterialData // Must align with struct in Object Srg
         {
-            AZStd::array<float, 2> m_uvMin;
-            AZStd::array<float, 2> m_uvMax;
-            float m_normalFactor;
+            AZStd::array<float, 2> m_uvMin{ 0.0f, 0.0f };
+            AZStd::array<float, 2> m_uvMax{ 1.0f, 1.0f };
+            float m_normalFactor{ 0.0f };
             uint32_t m_flipNormalX{ 0 }; // bool in shader
             uint32_t m_flipNormalY{ 0 }; // bool in shader
             uint32_t m_mapsInUse{ 0b00 }; // 0b01 = color, 0b10 = normal