std::vector<CR_VECTOR4> CMathHelper::CreateOccluderPlanes(const CR_VECTOR3 &pCameraPos, const CR_VECTOR3 *pCorners, const CR_VECTOR3 &pCenter, std::vector<CR_VECTOR3> &pPlanesSigns, std::vector<CR_VECTOR3> &pDebugPoints)
{
    assert(pCorners != nullptr);
    pPlanesSigns.clear();

    std::vector<int> cornerIds = { 0, 1, 5, 4, 4, 5, 7, 6, 6, 7, 3, 2, 2, 3, 1, 0, 1, 3, 7, 5 , 0, 4, 6, 2 };   // 6*4 = 24
    std::set<CR_VECTOR2I> visibleEdges;

    std::vector<CR_VECTOR4> planes;

    // find quads facing the camera (and use for 'near' planes) - planar, so 3 verts per quad is enough
    for(size_t verts=0;verts<cornerIds.size();verts+=4)
    {
        CR_VECTOR3 faceNormal;
        if(TriangleFacingPoint(pCorners[cornerIds[verts+1]], pCorners[cornerIds[verts+2]], pCorners[cornerIds[verts+3]], pCameraPos, faceNormal))
        {
            faceNormal *= -1.0f;    // flip normal, as it was pointing towards camera
            faceNormal.Normalize();

            float d = -DotProductVec3(pCorners[cornerIds[verts+1]], faceNormal);
            planes.emplace_back(CR_VECTOR4(faceNormal.x, faceNormal.y, faceNormal.z, d));
            pPlanesSigns.emplace_back(GetSigns(faceNormal));

            std::vector<CR_VECTOR2I> newEdges;
            newEdges.emplace_back(CR_VECTOR2I(cornerIds[verts], cornerIds[verts+1]));
            newEdges.emplace_back(CR_VECTOR2I(cornerIds[verts+1], cornerIds[verts+2]));
            newEdges.emplace_back(CR_VECTOR2I(cornerIds[verts+2], cornerIds[verts+3]));
            newEdges.emplace_back(CR_VECTOR2I(cornerIds[verts+3], cornerIds[verts]));

            for(auto && edge : newEdges)
            {
                edge.LowToHigh();
                auto it = visibleEdges.find(edge);
                if(it != visibleEdges.end())
                {
                    visibleEdges.erase(it);
                }
                else
                {
                    visibleEdges.insert(edge);
                }
            }
        }
    }

    // continue with 'sides' of the volume, based on the edges with duplicates
    for(auto && tEdge : visibleEdges)
    {
        CR_VECTOR3 faceNormal = CalculateFaceNormal(pCameraPos, pCorners[tEdge.x], pCorners[tEdge.y]);

        if(!TriangleFacingPoint(faceNormal, pCameraPos, pCenter))
        {
            faceNormal *= -1.0f;
        }
        faceNormal.Normalize();

        float d = -DotProductVec3(pCameraPos, faceNormal);
        planes.emplace_back(CR_VECTOR4(faceNormal.x, faceNormal.y, faceNormal.z, d));
        pPlanesSigns.emplace_back(GetSigns(faceNormal));
    }
    return planes;
}