Hello, I’ve been experimenting with the new xnurbs features. Unfortunately, I’m having a problem with them. This has nothing to do with the new beta version, though—it happens in previous versions as well. When I create a surface with xnurbs, I can’t join it to the adjacent surfaces. I get an error message (see image). When I zoom in on the boundaries, I see small gaps. I’ve tried changing the tolerance, but it doesn’t fix the gaps. What am I doing wrong? Left picture the xnurb betwenn the pipes, rigts picture boundarie with gaps.

There was a post (https://www.skool.com/ultimate-3d-membership-7140) with question that interested me many years ago. I tried to find good playground or illustration how spline curves and surfaces works. But there were too few of them. I made my own to understand spline math. I hope this helps someone: https://putyavka.github.io/bspline/dist/ Here is some notes about the playground: - curves and surfaces in Plasticity (as in other CADs) follows the same math model. You just usually cannot see how they are constructed because artists don't need these details - number or CV, degree and spans (segments) are strictly interconnected (any of them can be inferred from 2 others) - highlighted segment is controlled highlighted (black) CVs only. And this is the most interesting part. In a curve with degree 5 with 1 span all 6 points change the hole curve. In a curve with degree 3 and 3 spans only 4 consequent CVs control its span (there are exactly 3 variants of such sequence for each segment). And the advice for long curves from here is to add spans instead of covering CV number with high degree with single span. You won't be able to modify one end of curve without changing another - progress is the same as isoparam value (from 0 to 1) - rules show how regularly scattered progress (isoparam) maps points on the curve. You can see that denser located CVs creates denser isoparams at that region but stretch curve in others and it's bad for building curves, sparse isoparams have less control.

A lot of you asked... here it comes.

In the square command ,I do not see the option slider for constraints