Hello everyone
Today, when working on a model I encountered this problem:
Creating the red surfaces with _EdgeSrf, using 2 edges ( at the bottom of the yellow block and at the top of the white ones )
Everything’s fine, but when I have to _ExtrudeSrf ( 28mm towards the center of the block ) the 4 surfaces behave differently : front ones extrude correctly, back ones estrude towards an undefined point
Anyone has any idea onn why this happens ?
Here attached the actual model
Model.3dm (196.7 KB)
Your two ‘rear’ surfaces are not considered planar by Rhino, so it uses the current Z axis for the default extrusion direction, as it can’t find an extrusion plane from the surfaces themselves.
However, this is one of those cases where some of Rhino’s checks say the surfaces are planar - they are within about 0.0001, or far below file tolerance - however, ExtrudeSrf and SelPlanarSrf seem to be looking for a far lower tolerance, so it doesn’t consider them planar.
Crystal clear ! Thank you @Helvetosaur
Is there a way or a command to rebuild this kind of surfaces planar, within tolerances, without having to redraw it?
Yes, you can try this script. That’s actually how I determined how far out your surfaces were from ‘planar’. The only thing I can’t guarantee is that the two adjacent surface edges will join afterwards, in this case the adjustment is so tiny, I think it will be no problem. Also works on curves.
PlanarizeCurvesSrfs.py (4.4 KB)
I’ll give it a try ! Thank you
