Rhino - fillet edge

I’m doing a very basic 3D in Rhino, I’m pretty beginner at it.
I have an object, when I try to fillet the edges, it fails and goes nuts
The object was created using an ellipsoid and a bouncing box.
Its a pair of legs, and the inside of them need to be fillet

What happens :

I fillet the legs, all edges at once with a .2 cm radius, and its not smooth and creates holes in the object
I fillet the legs with .5 cm radius all at once and long pieces start forming out of it

I’ve shared a few photos so you could see what I mean

Hi Melissa- please post the object in a Rhino file if you can, or send to tech@mcneel.com.



legs.3dm (439.9 KB)

Hi Melissa- I see two things that could help -

  1. it looks like .2 is a little large to fit cleanly in the tighter radii of the edge itself - .15 seems OK, and you might ‘addHandle’ in the FilletEdge command to make the middle part closer to .2- in otherwords, use a variable radius.

  2. The middle surface in the cutout part is not quite tangent to the outer ones- I’d remake the cutter there, making sure the curves are at least tangent before extruding it.


Hi Pascal, thanks a lot for the advice.
Adding handles helps, but not entirely, there is still a hole, also the edges become rounded, but the inside of the legs are still straight.
I dont quite get your second recommendation
What i did was use an ellipsoid and then put it in a bounding box to make it into the form i wanted.
To make the cutout between the legs i did a boolean, is that what i did wrong?

I attached a picture of the form i began with before doing boolean


Hi Melissa - these curves are not tangent:

Use GCon to check these. The report from GCon (Analyze menu > Curve> Geometric continuity) should, ideally tell you that there is 0 degrees tangency difference between the red and black curves. In this case, replace the red curve with a new BlendCurve and then Join and Extrude to make your cutter (Boolean).

FilletEdge then works well at .15 and .2 as I’ve called out in the attached file…

legs_pg.3dm (323.4 KB)


Thanks i’ll try that.
Could you send the file in an older model, cant open it!

thanks again! Ill let you know if i could figure this out.

legs_pg_V4.3dm (327.4 KB)