I want to generate a surface using a series of arcs. The surface would curve in 3 directions.
I want to then generate sections from the surface to produce a series of arcs - not b spline curves. Is there any way to maintain the arc geometry, when using the 'generate section tool (and not b splines)
We don't want to work with b splines at all.
dodgem: I want to generate a surface using a series of arcs. We don't want to work with B-splines at all.
I want to generate a surface using a series of arcs. We don't want to work with B-splines at all.
I'm rather fond of B-splines, but we each have our own preferences. I suggest that you generate sections using B-splines, then drop the B-splines to arcs once the section has been created.
Have you considered Generative Components (GC)?
Regards, Jon Summers LA Solutions
Curvature in two directions using arcs = torus patch. Please take a look at Ben Doherty's brief torus patch tutorial. However, depending on the extents of your torus patch and how you section through it you more often get elliptical arcs than circular arcs (well, theoretically an infinite number of each, plus other geometry depending on the shape of the patch boundary). If the arcs need to have varying radii, then you may use conical patches; however, those are curved in only one direction and you get all the variety of conical sections when sectioning those. If none of those serve you well, then you quickly enter the territory of B-spline geometry, even when using section arcs as generating (loft) curves for your geometry (for example your required or desired resulting sections, if you back track from desired result to generating shape).
Questions here need to be: what is the reason for the circular arc requirement (then the six remaining Why? questions) and then wondering how to achieve that intent with different means.
Especially when working back from resultant arc sections to the shape that generates those sections, Jon's referral to GenerativeComponents is worthwhile considering because that will allow you to set up a parametric system that will respond to changing requirements without you having to rebuild your model each time requirements change (for example the section locations).
Although I don't have it at hand right now (it sits at home on my bookshelves) I am very certain that the book Architectural Geometry by Helmut Pottmann, Andreas Asperl, Michael Hofer, and Axel Kilian further illuminates this issue.