Bounded NURBS surface

Hello, I have a NURBS surface but It is bounded by curves just like in the figure below, I understand Three.js doesn’t support cutting NURBS. Can someone point me to an approach or a library (or maybe a three.js addon) that can deal with bounded NURBS?

Looking at the provided picture, seems you need discarding of pixels, that depends on UV coordinates.
For that specific case, there is an option:


discarding of pixels seems like a nice approach, the example you gave me is as you said case specific, but in my case the bounding curves can change, do you have any idea how to detect the “Border” value based on these curves?

Would be cool to provide an example with limiting curves :slight_smile: