Simpler process to create "fillet" in single surface

Rhino Rhino for Windows
1

G’day everyone,

I have a need to create many single surfaces with bends for use in a downstream application that treats polysurfaces as separate items. Currently I can create these manually, but with lots of bends and many surfaces it is quite time-consuming. The basic process at the moment is as such:

  1. Extrude profile to create open polysurface.
  2. FilletEdge each bend.
  3. Explode
  4. MergeSrf

There’s a bit of un-trimming and re-trimming in there too, which makes the process even longer.

It seems that the extrudecrv option to not splitattangents seems like it should result in a single surface rather than a polysrf, but that assumption doesn’t appear to be correct.

I’d love to just be able to start with a sharp cornered polysrf and fillet the edges straight into a single surface, similar to mergesrf. Is this possible?

Anyone got any hints for this?

2

Hi Nick - put the fillets in the curve to extrude, set UseExtrusions to make polysurfaces rather than extrusions, and the SplitAtTangents setting will work as you expect - it cannot work on extrusion objects. Any luck?

-Pascal

1 Like
3

Bingo, I missed the UseExtrusions toggle, thank you pascal. Serves me right for upgrading the computer and missing important settings like that.

Now for bonus points, what if I’ve already been given a lot of the polysrf with the fillets and don’t desire to remake them?

4

Hi Nick it’s a bit unclear, to say the least, how useExtrusions and SplitAtTangents work together. As for fixing the existing ones - what I can think of at the moment involves some gyrations but it might work… I gather the shapes have been trimmed so that the edges defining the extrusion shapes are no longer intact?

Here’s a plug-in, it has ConvertToExtrusion
ExtrusionTools.rhp (20 KB)

DupBorder on the polysurface, then ConvertToExtrusion (pick and Extrusion direction edge, and set DeleteInput to Yes)- this will return an extrusion with re-squared ends (i.e. ignores the trims on the ends). Re-extrude as a polysurface from one end’s edge curves and trim the result with the border curves. I have no idea if that is any more efficient than any other way, even assuming I’ve got the problem by the correct end.

This might not be different than merely selecting the objects, ShrinkTrimmedSrf, Explode, UntrimAll and re-extruding the edges - I’m kind of making stuff up here - send an example if you like…
-Pascal

5

Thanks @pascal, that’s not much quicker than what I’m doing at the moment. A few of the bent parts were bogus downstream anyway so I’m rebuilding most of them.