Fixing tree and adding unit tests

res/shaders/BasePass.slang

@@ -29,5 +29,5 @@ float4 fragmentMain(in FragmentParameter params) : SV_Target
     {
         result += pLightEnv.pointLights[i].illuminate(lightingParams, brdf);
     }
-    return float4(result, 1.0f);
+    return float4(params.vertexColor, 1.0f);
 }

res/shaders/MeshletBasePass.slang

@@ -120,6 +120,7 @@ void meshMain(
 		{
 			uint vertexIndex = pScene.vertexIndices[m.vertexOffset + v];
 			VertexAttributes attr = pVertexData.getAttributes(md.indicesOffset + vertexIndex);
+			attr.vertexColor = m.color;
 			vertices[v] = attr.getParameter(inst.transformMatrix);
 		}
 	}

res/shaders/lib/Scene.slang

@@ -7,6 +7,8 @@ struct MeshletDescription
 	uint32_t primitiveCount;
 	uint32_t vertexOffset;
 	uint32_t primitiveOffset;
+	float3 color;
+	float pad;
 };
 
 struct MeshData