FilletEdge will not allow selection of edges associated to faces with small dihedral angle, whatever radius is input for the fillet :
FilletEdge fails on small diedral angle.3dm (116.6 KB)
I managed to select the edge in question and to make a fillet, but strangely that was after adding another face to the polysurface.
Now I need to make a fillet with this new face, but the dihedral angle is even smaller, and I just can’t select the edge again…
Miracle on one edge-Not the other.3dm (93.9 KB)
Well, the one that doesn’t work has an dihedral angle of less than 1°, and your angle tolerance is 1° - so Rhino considers them “tangent”… (I would suggest working with a default of 0.1° for angle tolerance, the default of 1° is far too large)
However, that is not all that is going on, FilletEdge must have some hard-coded internal cutoffs somewhere. I tried with FilletSrf, and whether or not the fillet is created depends also on the file absolute tolerance - I think in order to avoid creating extremely skinny surfaces… (my theory at least). So I was able to get FilletSrf to work by lowering the file tolerance. The more I lowered it, the smaller radius it would accept to make the fillet… So there is some internal checking going on… @chuck?
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Yes, but in my first file, the dihedral angle is more than 1°, and I could not select the edge.
It was only after adding another face that I could select it.
I measured it as 0.72° approximately… But yes, there is something else going on besides that.
You are right.
Looks like the test uses the default angle tolerance of 1 degree. I’ll make a youtrack to see if it can be changed to use the file’s angle tolerance.
https://mcneel.myjetbrains.com/youtrack/issue/RH-56332
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