Degree 1 bSplineSurface?

EvanReese
EvanReese Member, Mentor Posts: 3,086 PRO
Is there a fundamental reason we can't make a degree 1 bSplineSurface? It could be handy to make some interesting faceted designs. It works in Rhino, and gives the result on the right.
Evan Reese
The Onsherpa | Reach peak Onshape productivity
www.theonsherpa.com
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Answers

  • S1mon
    S1mon Member Posts: 4,588 PRO
    So in this case, Rhino is sampling the surface on the left to get points which are theoretically a series of knots in a degree-1 B-Splines (basically making a bunch of poly lines). 

    How are you trying to construct the b-splines to build the b-splinesurface? Are you generating the sampled points?

    Simon Gatrall | Product Development, Engineering, Design, Onshape | Ex- IDEO, PCH, Unagi, Carbon | LinkedIn

  • EvanReese
    EvanReese Member, Mentor Posts: 3,086 PRO
    edited September 2022
    I've not really started anything. I was just curious if it would work and found that for b-spline curves and surfaces in Onshape the minimum degree is 2 and wondered why. For my test, I just started with a grid of points and was able to generate degree 2+ surfaces, but get an error at degree 1.
    Evan Reese
    The Onsherpa | Reach peak Onshape productivity
    www.theonsherpa.com
  • S1mon
    S1mon Member Posts: 4,588 PRO
    Interesting. You've probably seen this, but you can create degree-1 Béziers in sketcher (it will even let you make things parallel or perpendicular to them!).

    It's unfortunate if you can't make a degree -1 surface. Of course you could make degree-2 curves (which are still lines) by adding a control points midway between the endpoints.

    Are you trying to do this as one multi-span b-spline surface, or are you ok with making 64 surfaces and boolean-ing them together?

    Simon Gatrall | Product Development, Engineering, Design, Onshape | Ex- IDEO, PCH, Unagi, Carbon | LinkedIn

  • EvanReese
    EvanReese Member, Mentor Posts: 3,086 PRO
    I'm not really trying to do anything in particular. I just thought it would be cool if it were possible, since I could use it to easily make something like a faceted loft tool, or a way to convert existing faces to a faceted version. If it can't be done this way, I don't expect to pursue it much more at the moment.
    Evan Reese
    The Onsherpa | Reach peak Onshape productivity
    www.theonsherpa.com