Fix the sky in one of the levels in virtua on. The problem was caused by the fact we didn't split the mesh by the fog % burn through, so all the polys had the same value. We could use a vertex attrib, but % burn through fog is so rarely used and when it is, normally every poly in the mesh has the same value.

Src/Graphics/New3D/PolyHeader.cpp

@@ -401,6 +401,7 @@ UINT64 PolyHeader::Hash()
 	hash |= (UINT64)HighPriority() << 38;				// bits 38 high priority enable
 	hash |= (UINT64)SpecularEnabled() << 39;			// bits 39 enable specular reflection
 	hash |= (UINT64)SmoothShading() << 40;				// bits 40 smooth shading
+	hash |= (UINT64)((header[6] >> 11) & 0x1F) << 41;	// bits 41-45 light modifier
 
 	//to do add the rest of the states