@James: Thanks James. Once again. I need to dig into it.

@Michael: Is it changing something with calulation local Normal direction from point layed over the surface? I see that face.evaluateNormal( uv ) and I not`t understand what is U and V values. I know UV but in polygonal modeling.

https://www.researchgate.net/profile/Arthur_Van_Der_Harten/publication/260596792/figure/fig2/AS:296811131621382@1447776696970/NURBS-Surface-parametrized-with-u-and-v-values-from-0-to-1.png

Is it works also for rounded shapes? Is there some node to return U and V values for given point? I yes then it should be easy to get normal direction after your latest update.