Variable radius fillet

Rhino Developer
1

Hi guys,

Is Variable Radius Fillet is available in RhinoCommon? Cannot find it.

Thanks,
Dmitriy

2

Hi Dmitriy,

No, there is not. There is a CRhinoFilletEdge class in the C++ SDK that fillets, chamfers, or blends the edges of a Brep. Does this sound like what you need?

3

Hi Dale,

Thanks.
That is exactly what I need.

At the moment I am using temporary solution:

  1. Offsetting edge on both BrepFaces
  2. Extend curves on the BrepFace
  3. Trim those faces with obtained curves.
  4. Blend curves along the edge.
  5. Generate surface with 2rails method.

However this is not very precise way - in order to control shape you need quite some input blended curves

KR, Dmitriy

4

I’ve added this to the RhinoCommon to-do list.

– Dale

5

Is there any progress on this?

6

This wish and resolution are documented in our issue tracker: https://mcneel.myjetbrains.com/youtrack/issue/RH-27996

This has been added to RhinoCommon in Rhino 6: http://developer.rhino3d.com/wip/api/RhinoCommonWin/html/M_Rhino_Geometry_Brep_CreateFilletEdges.htm

7

Hi @dale and @fraguada,

coming back to this, i have 2 surfaces and need to create a variable fillet surface or blend surface between them, unfortunately with multiple radii. Is there anything in RhinoCommon to accomplish this yet ?

I am aware of Brep.CreateBlendShape but this creates only perpendicular sections and if i want to use them in order to create a SweepTwoRail there is no way to control continuity along the 2 brep edges and i actually would have to create those edges myself.

thanks, c.

8

Hi @clement,

How about Brep.CreateFilletEdges?

– Dale

9

Hi @dale, i’ve seen this but it only allows to define one start and end radius per edge. Actually i have no shared edge (yet). I only have 2 almost touching surfaces and 8 different radii .
_
c.

10

@chuck - any suggestions for @clement?

– Dale

11

There is nothing in any of the fillet code that will work here. This might be a better question for @pascal

12

I do not have a good idea I’m afraid. Are the rails still to be calculated or does everything need to ride on the existing non-touching edge? Not that I have a suggestion either way, I’m just trying to picture what’s needed.

-Pascal

13

Hi @chuck and @pascal,

That’s actually the problem, i have no rails. What i have is two unjoinable surfaces with a small gap between and a bunch of variing radii. I’ve tried to extend both surfaces near the edge i would like to fillet so i can split and join them using a boolean operation but the resulting edge i could use to fillet is rather ugly and this propagates to to a fillet when done using FilletEdge.

So i tried to just make a pipe with variing radii and split apart everything in the pipe, then make (many) perpendicular blend sections on my own which i can use to SweepTwoRail but since it does not offer to use continuity along the 2 rails (edges), the result does not meet the requirements.

What i would need, i guess, is some kind of _FilletSrf but with control over the rolling ball radius. The good thing about _FilletSrf is that i can just feed it with the surfaces and it finds the edges on it’s own.

_
c.