src/BulletMultiThreaded/GpuSoftBodySolvers/DX11/HLSL/UpdateNormals.hlsl

   1 MSTRINGIFY(\r
   2 \r
   3 cbuffer UpdateSoftBodiesCB : register( b0 )\r
   4 {\r
   5         unsigned int numNodes;\r
   6         unsigned int startFace;\r
   7         unsigned int numFaces;\r
   8         float epsilon;\r
   9 };\r
  10 \r
  11 \r
  12 // Node indices for each link\r
  13 StructuredBuffer<int4> g_triangleVertexIndexSet : register( t0 );\r
  14 StructuredBuffer<float4> g_vertexPositions : register( t1 );\r
  15 StructuredBuffer<int> g_vertexTriangleCount : register( t2 );\r
  16 \r
  17 RWStructuredBuffer<float4> g_vertexNormals : register( u0 );\r
  18 RWStructuredBuffer<float> g_vertexArea : register( u1 );\r
  19 RWStructuredBuffer<float4> g_triangleNormals : register( u2 );\r
  20 RWStructuredBuffer<float> g_triangleArea : register( u3 );\r
  21 \r
  22 \r
  23 [numthreads(128, 1, 1)]\r
  24 void \r
  25 ResetNormalsAndAreasKernel( uint3 Gid : SV_GroupID, uint3 DTid : SV_DispatchThreadID, uint3 GTid : SV_GroupThreadID, uint GI : SV_GroupIndex )\r
  26 {\r
  27         if( DTid.x < numNodes )\r
  28         {\r
  29                 g_vertexNormals[DTid.x] = float4(0.0f, 0.0f, 0.0f, 0.0f);\r
  30                 g_vertexArea[DTid.x] = 0.0f;\r
  31         }\r
  32 }\r
  33 \r
  34 \r
  35 [numthreads(128, 1, 1)]\r
  36 void \r
  37 UpdateSoftBodiesKernel( uint3 Gid : SV_GroupID, uint3 DTid : SV_DispatchThreadID, uint3 GTid : SV_GroupThreadID, uint GI : SV_GroupIndex )\r
  38 {\r
  39         int faceID = DTid.x + startFace;\r
  40         if( DTid.x < numFaces )\r
  41         {               \r
  42                 int4 triangleIndexSet = g_triangleVertexIndexSet[ faceID ];\r
  43                 int nodeIndex0 = triangleIndexSet.x;\r
  44                 int nodeIndex1 = triangleIndexSet.y;\r
  45                 int nodeIndex2 = triangleIndexSet.z;\r
  46 \r
  47                 float3 node0 = g_vertexPositions[nodeIndex0].xyz;\r
  48                 float3 node1 = g_vertexPositions[nodeIndex1].xyz;\r
  49                 float3 node2 = g_vertexPositions[nodeIndex2].xyz;\r
  50                 float3 nodeNormal0 = g_vertexNormals[nodeIndex0].xyz;\r
  51                 float3 nodeNormal1 = g_vertexNormals[nodeIndex1].xyz;\r
  52                 float3 nodeNormal2 = g_vertexNormals[nodeIndex2].xyz;\r
  53                 float vertexArea0 = g_vertexArea[nodeIndex0];\r
  54                 float vertexArea1 = g_vertexArea[nodeIndex1];\r
  55                 float vertexArea2 = g_vertexArea[nodeIndex2];\r
  56                 \r
  57                 float3 vector0 = node1 - node0;\r
  58                 float3 vector1 = node2 - node0;\r
  59                 \r
  60                 float3 faceNormal = cross(vector0.xyz, vector1.xyz);\r
  61                 float triangleArea = length(faceNormal);\r
  62 \r
  63                 nodeNormal0 = nodeNormal0 + faceNormal;\r
  64                 nodeNormal1 = nodeNormal1 + faceNormal;\r
  65                 nodeNormal2 = nodeNormal2 + faceNormal;\r
  66                 vertexArea0 = vertexArea0 + triangleArea;\r
  67                 vertexArea1 = vertexArea1 + triangleArea;\r
  68                 vertexArea2 = vertexArea2 + triangleArea;\r
  69                 \r
  70                 g_triangleNormals[faceID] = float4(normalize(faceNormal), 0.f);\r
  71                 g_vertexNormals[nodeIndex0] = float4(nodeNormal0, 0.f);\r
  72                 g_vertexNormals[nodeIndex1] = float4(nodeNormal1, 0.f);\r
  73                 g_vertexNormals[nodeIndex2] = float4(nodeNormal2, 0.f);\r
  74                 g_triangleArea[faceID] = triangleArea;\r
  75                 g_vertexArea[nodeIndex0] = vertexArea0;\r
  76                 g_vertexArea[nodeIndex1] = vertexArea1;\r
  77                 g_vertexArea[nodeIndex2] = vertexArea2;\r
  78         }\r
  79 }\r
  80 \r
  81 [numthreads(128, 1, 1)]\r
  82 void \r
  83 NormalizeNormalsAndAreasKernel( uint3 Gid : SV_GroupID, uint3 DTid : SV_DispatchThreadID, uint3 GTid : SV_GroupThreadID, uint GI : SV_GroupIndex )\r
  84 {\r
  85         if( DTid.x < numNodes )\r
  86         {\r
  87                 float4 normal = g_vertexNormals[DTid.x];\r
  88                 float area = g_vertexArea[DTid.x];\r
  89                 int numTriangles = g_vertexTriangleCount[DTid.x];\r
  90                 \r
  91                 float vectorLength = length(normal);\r
  92                 \r
  93                 g_vertexNormals[DTid.x] = normalize(normal);\r
  94                 g_vertexArea[DTid.x] = area/float(numTriangles);\r
  95         }\r
  96 }\r
  97 \r
  98 );