Decimation of cubic meshes is only supported in the CubicSurfaceExtractor, and not in the CubicSurfaceExtractorWithNormals. So in general we would recommend using the version without normals, and then creating normals in the fragment shader when you want to perform lighting. You can read ho to do this here:
http://www.volumesoffun.com/polyvox/doc ... bic-meshesYou should also read this:
http://www.volumesoffun.com/polyvox/doc ... bic-meshesAnd be aware of this issue:
https://bitbucket.org/volumesoffun/poly ... lificationHope that helps :-)