Fix a bug to sample uv.

Author: mattatz

Assets/Packages/Voxelizer/Scripts/GPUVoxelizer.cs

@@ -13,7 +13,7 @@ public class GPUVoxelizer {
 
 		protected const string kVolumeKernelKey = "Volume", kSurfaceKernelKey = "Surface", kTextureKernelKey = "BuildTexture3D";
 		protected const string kStartKey = "_Start", kEndKey = "_End", kSizeKey = "_Size";
-		protected const string kUnitKey = "_Unit", kHalfUnitKey = "_HalfUnit";
+		protected const string kUnitKey = "_Unit", kInvUnitKey = "_InvUnit", kHalfUnitKey = "_HalfUnit";
 		protected const string kWidthKey = "_Width", kHeightKey = "_Height", kDepthKey = "_Depth";
 		protected const string kTriCountKey = "_TrianglesCount";
 		protected const string kVertBufferKey = "_VertBuffer", kUVBufferKey = "_UVBuffer", kTriBufferKey = "_TriBuffer";
@@ -73,6 +73,7 @@ public static GPUVoxelData Voxelize(ComputeShader voxelizer, Mesh mesh, int coun
 			voxelizer.SetVector(kSizeKey, bounds.size);
 
 			voxelizer.SetFloat(kUnitKey, unit);
+			voxelizer.SetFloat(kInvUnitKey, 1f / unit);
 			voxelizer.SetFloat(kHalfUnitKey, unit * 0.5f);
 			voxelizer.SetInt(kWidthKey, w);
 			voxelizer.SetInt(kHeightKey, h);

Assets/Packages/Voxelizer/Shaders/Voxelizer.compute

@@ -10,7 +10,7 @@
 CBUFFER_START(VoxelParams)
 
 float3 _Start, _End, _Size;
-float _Unit, _HalfUnit;
+float _Unit, _InvUnit, _HalfUnit;
 
 int _Width, _Height, _Depth;
 
@@ -88,7 +88,7 @@ void voxelize_surface(int x, int y)
         float u, v;
         float dist = tri_hit(ori, dir, v0, v1, v2, u, v);
         if(dist >= 0.0) {
-            int z = dist / _Unit;
+            int z = dist * _InvUnit;
             uint vid = get_voxel_index(x, y, z);
             Voxel voxel;
 
@@ -97,7 +97,7 @@ void voxelize_surface(int x, int y)
             float2 uv2 = _UVBuffer[c];
 
             voxel.position = get_voxel_position(x, y, z);
-            voxel.uv = lerp(uv0, uv1, u) + lerp(uv0, uv2, v);
+            voxel.uv = u * uv1 + v * uv2 + (1.0 - u - v) * uv0;
             voxel.flag = true;
             _VoxelBuffer[vid] = voxel;
         }