topic Re: How to make a Surface from 3 splines? in Fusion Design, Validate & Document Forum

How to make a Surface from 3 splines?

jimmy.laww — Sun, 24 Apr 2022 13:28:02 GMT

I'd like to 'patch' a 3 spline hole in an object I've created. The patch command itself won't work since the hole isn't made of one sketch but two. And loft doesn't seem to work either. Perhaps I'm approaching it from the wrong direction tho?

Does anyone know how I would go about achieving this? I've attached the scene file. Any help much appreciated.

Re: How to make a Surface from 3 splines?

TrippyLighting — Sun, 24 Apr 2022 13:37:57 GMT

Triangular lofts are to be avoided. Lofts create NURBS surfaces. The control point mesh that determine the shape of a surface is always quadrilinear. When you loft a triangle, you are collapsing the control points of one edge into a single point, called singularity. Approaching that point , the curvature will become uneven and that can result in all sorts of modeing problems e.g. filleting, shelling etc.

In this case, use a patch and check that the resulting edges have smooth curvature (they do).

That patch is creating a trimmed NURBS surface, which is the only other way to create a triangular NURBS surface.

Re: How to make a Surface from 3 splines?

hamid.sh. — Sun, 24 Apr 2022 13:44:00 GMT

Haven't looked into your file, and not saying this is the best solution, but being two sketches can be easily remedied: make a new sketch, Project/Include > Include 3D Geometry, select 3 sketch lines to have a linked copy of them in a single sketch.

Re: How to make a Surface from 3 splines?

aliobidi — Sun, 24 Apr 2022 13:48:49 GMT

Hi ,
your file below

Re: How to make a Surface from 3 splines?

jimmy.laww — Sun, 24 Apr 2022 14:07:11 GMT

Thanks for the replies everyone. I'm not too sure how both solutions have actually been reached though?

@TrippyLightingYou mean Surface/Patch right? If so, when I do this I can only select one spline? So it doesn't work for me. What is that edit box you have there too? If you could talk me through your process a bit that would be great.

@aliobidiSimilarly, could you say how you actually achieved that?

Re: How to make a Surface from 3 splines?

aliobidi — Sun, 24 Apr 2022 14:10:37 GMT

watch this

Re: How to make a Surface from 3 splines?

TrippyLighting — Sun, 24 Apr 2022 14:19:23 GMT

@jimmy.laww wrote:

... If so, when I do this I can only select one spline?

IF you de-select "Chaining" in the UI you can select each boundary spline/edge individually.

Re: How to make a Surface from 3 splines?

jimmy.laww — Mon, 25 Apr 2022 15:58:13 GMT

@aliobidiMany thanks!

Re: How to make a Surface from 3 splines?

TrippyLighting — Mon, 25 Apr 2022 16:11:40 GMT

You’re most welcome …