I am having problems adding a fillet in Grasshopper to a brep composed of the solid union of a couple extrusions.

After playing with it, I have reduced it down to a very simple example. The brep is a union of 2 flat sided solids - one an extruded rectangle, the other an extruded parallelogram.

I am trying to use fillet on some of the intersections. I found the correct edge indices, but fillet acts very strangely.

The parallelogram is 15 degrees off of vertical. There is one fillet between faces with an acute angle (75 degrees). It seems to work properly. The obtuse angle (105 degrees) seems to cause problems.

Strangely, the success of the fillet seems to depend on the length of the rectangular box!

For length = 459, (see uploaded file) the fillet works!

For length = 460, fillet fails.

For length = 450, fillet thinks it worked, but the preview shows the fillet extending off into space in the positive y-direction, but only on the fillet for the obtuse angle side.

Other values of length show it extending off in the negative y-direction.

I am new to Grasshopper, so maybe I did something wrong. But it must be almost right to work in some cases.

Nathan

problem with fillet.gh (20.6 KB)