Updated handling of BLASTriangleDesc::VertexValueType and VertexComponentCount

3 files changed, 35 insertions, 13 deletions

diff --git a/Graphics/GraphicsEngine/interface/BottomLevelAS.h b/Graphics/GraphicsEngine/interface/BottomLevelAS.h
index bd80e3e4..c93319da 100644
--- a/Graphics/GraphicsEngine/interface/BottomLevelAS.h
+++ b/Graphics/GraphicsEngine/interface/BottomLevelAS.h
@@ -58,15 +58,24 @@ struct BLASTriangleDesc
     Uint32                    MaxVertexCount        DEFAULT_INITIALIZER(0);
 
     /// The type of vertices in this geometry, see Diligent::VALUE_TYPE.
+
+    /// \remarks Only the following combinations of VertexValueType and VertexComponentCount
+    ///          are allowed:
+    ///          * FLOAT32 x 2 (third component is assumed 0)
+    ///          * FLOAT32 x 3
+    ///          * FLOAT16 x 2 (third component is assumed 0)
+    ///          * FLOAT16 x 4 (fourth component is ignored)
+    ///          * INT16   x 2 (16-bit signed-normalized, third component is assumed 0)
+    ///          * INT16   x 4 (16-bit signed-normalized, fourth component is ignored)
     VALUE_TYPE                VertexValueType       DEFAULT_INITIALIZER(VT_UNDEFINED);
 
     /// The number of components in the vertex.
-    /// 2 and 3 are supported.
+    /// See VertexValueType for the list of allowed VertexValueType and VertexComponentCount combinations.
     Uint8                     VertexComponentCount  DEFAULT_INITIALIZER(0);
 
     /// The maximum primitive count in this geometry.
     /// The current number of primitives is defined in BLASBuildTriangleData::PrimitiveCount.
-    Uint32                    MaxPrimitiveCount         DEFAULT_INITIALIZER(0);
+    Uint32                    MaxPrimitiveCount     DEFAULT_INITIALIZER(0);
 
     /// Index type of this geometry, see Diligent::VALUE_TYPE.
     /// Must be VT_UINT16, VT_UINT32 or VT_UNDEFINED.
diff --git a/Graphics/GraphicsEngine/src/BottomLevelASBase.cpp b/Graphics/GraphicsEngine/src/BottomLevelASBase.cpp
index 46d82244..c0e8f058 100644
--- a/Graphics/GraphicsEngine/src/BottomLevelASBase.cpp
+++ b/Graphics/GraphicsEngine/src/BottomLevelASBase.cpp
@@ -63,11 +63,11 @@ void ValidateBottomLevelASDesc(const BottomLevelASDesc& Desc) noexcept(false)
             if (tri.GeometryName == nullptr)
                 LOG_BLAS_ERROR_AND_THROW("pTriangles[", i, "].GeometryName must not be null");
 
-            if (tri.VertexValueType >= VT_NUM_TYPES)
-                LOG_BLAS_ERROR_AND_THROW("pTriangles[", i, "].VertexValueType must be a valid type");
-
-            if (tri.VertexComponentCount != 2 && tri.VertexComponentCount != 3)
-                LOG_BLAS_ERROR_AND_THROW("pTriangles[", i, "].VertexComponentCount must be 2 or 3");
+            if (!((tri.VertexValueType == VT_FLOAT32 && (tri.VertexComponentCount == 2 || tri.VertexComponentCount == 3)) ||
+                  (tri.VertexValueType == VT_FLOAT16 && (tri.VertexComponentCount == 2 || tri.VertexComponentCount == 4)) ||
+                  (tri.VertexValueType == VT_INT16 && (tri.VertexComponentCount == 2 || tri.VertexComponentCount == 4))))
+                LOG_BLAS_ERROR_AND_THROW("pTriangles[", i, "].VertexValueType (", GetValueTypeString(tri.VertexValueType),
+                                         ") and .VertexComponentCount (", tri.VertexComponentCount, ") is not a valid combination");
 
             if (tri.MaxVertexCount == 0)
                 LOG_BLAS_ERROR_AND_THROW("pTriangles[", i, "].MaxVertexCount must be greater than 0");
diff --git a/Graphics/GraphicsEngineD3D12/src/BottomLevelASD3D12Impl.cpp b/Graphics/GraphicsEngineD3D12/src/BottomLevelASD3D12Impl.cpp
index 02e45b0e..5bb182dc 100644
--- a/Graphics/GraphicsEngineD3D12/src/BottomLevelASD3D12Impl.cpp
+++ b/Graphics/GraphicsEngineD3D12/src/BottomLevelASD3D12Impl.cpp
@@ -68,12 +68,25 @@ BottomLevelASD3D12Impl::BottomLevelASD3D12Impl(IReferenceCounters*          pRef
                 dst.Flags                                = D3D12_RAYTRACING_GEOMETRY_FLAG_NONE;
                 dst.Triangles.VertexBuffer.StartAddress  = 0;
                 dst.Triangles.VertexBuffer.StrideInBytes = 0;
-                dst.Triangles.VertexFormat               = TypeToDXGI_Format(src.VertexValueType, src.VertexComponentCount, src.VertexValueType < VT_FLOAT16);
-                dst.Triangles.VertexCount                = src.MaxVertexCount;
-                dst.Triangles.IndexCount                 = src.IndexType == VT_UNDEFINED ? 0 : src.MaxPrimitiveCount * 3;
-                dst.Triangles.IndexFormat                = ValueTypeToIndexType(src.IndexType);
-                dst.Triangles.IndexBuffer                = 0;
-                dst.Triangles.Transform3x4               = 0;
+
+                // Vertex format must be one of the following (https://docs.microsoft.com/en-us/windows/win32/api/d3d12/ns-d3d12-d3d12_raytracing_geometry_triangles_desc):
+                //  * DXGI_FORMAT_R32G32_FLOAT       - third component is assumed 0
+                //  * DXGI_FORMAT_R32G32B32_FLOAT
+                //  * DXGI_FORMAT_R16G16_FLOAT       - third component is assumed 0
+                //  * DXGI_FORMAT_R16G16B16A16_FLOAT - A16 component is ignored, other data can be packed there, such as setting vertex stride to 6 bytes.
+                //  * DXGI_FORMAT_R16G16_SNORM       - third component is assumed 0
+                //  * DXGI_FORMAT_R16G16B16A16_SNORM - A16 component is ignored, other data can be packed there, such as setting vertex stride to 6 bytes.
+                dst.Triangles.VertexFormat = TypeToDXGI_Format(src.VertexValueType, src.VertexComponentCount, src.VertexValueType < VT_FLOAT16);
+                VERIFY(dst.Triangles.VertexFormat == DXGI_FORMAT_R32G32_FLOAT || dst.Triangles.VertexFormat == DXGI_FORMAT_R32G32B32_FLOAT ||
+                           dst.Triangles.VertexFormat == DXGI_FORMAT_R16G16_FLOAT || dst.Triangles.VertexFormat == DXGI_FORMAT_R16G16B16A16_FLOAT ||
+                           dst.Triangles.VertexFormat == DXGI_FORMAT_R16G16_SNORM || dst.Triangles.VertexFormat == DXGI_FORMAT_R16G16B16A16_SNORM,
+                       "Unsupported vertex format");
+
+                dst.Triangles.VertexCount  = src.MaxVertexCount;
+                dst.Triangles.IndexCount   = src.IndexType == VT_UNDEFINED ? 0 : src.MaxPrimitiveCount * 3;
+                dst.Triangles.IndexFormat  = ValueTypeToIndexType(src.IndexType);
+                dst.Triangles.IndexBuffer  = 0;
+                dst.Triangles.Transform3x4 = 0;
 
                 MaxPrimitiveCount += src.MaxPrimitiveCount;
             }