CageEdit and problem of Zebra



Hello, if to create the simple sphere and to begin to transform it by means of CageEdit (at BoundingBox + Global) - there is a problem in a zebra. But why?

(David Cockey) #2

Difficult to say without seeing your .3dm file. Can you post it here? Either drag it to this window, or use the vertical upload arrow in the row above where you type your post.


Untitled.3dm (2.7 MB)

I think that the zebra has to be smooth and without the slightest defects.

Or here:
Untitled.3dm (3.8 MB)

(David Cockey) #4

I don’t see the problems you see in either file. Perhaps you could put a bright color point a the locations of the problems. Start the Point command, type OnSrf, pick the surface and then the location for the point.

What Zebra Stripe size setting are you using

Two reasons the zebra pattern may have a “defect”. One is the NURBS surface has a defect.

The other is due to the mesh used in calculating the zebra pattern. If the mesh is too coarse or there is too large an angle between adjacent mesh panels then a kink or other defect in the displayed zebra pattern can result.


Look near the ends of the seam.

(David Cockey) #6

I still don’t see anything.


What grid settings do you use?
You can attach images of zebra on the ends of the seam at the second file?


I see it, but I think it’s a trivial mistake.

If you want a perfect mesh manage the number of control points.


I don’t understand, you suggest to use the RebuildUV tool?


I would try to split the surface into quads.

extract isocurves - remake them with managable amount of points (degree +1) - rebuild surfaces

Maybe you will have to rebuild those isocurves manually rather than fully relying on automatic result.

On the other hand you could also try a quick and dirty way of splitting the surface with cut isocurves and inserting a manual patch just on the problem area.

I recommend the clean way.

Also it’s probably just a meshing error rather than an actual error.


There’s probably something else … The curvature map does not see the zebra problem.


I have carried out tests and have allocated a problem. If to use CageEdit at PreserveStructure=Yes, then the zebra has defects on the ends of a seam. And at PreserveStructure=No all super!



However the good zebra has a small problem in curvature. Is it normal?

No problem!
It is necessary to improve at first geometry (degree 6), and already then to use CageEdit at PreserveStructure=No.


I have created the usual sphere, I use CageEdit, and then I try to divide a surface into 2 parts - a mistake “Split failed, objects mayn’t intersect or intersections mayn’t split object” :frowning:
1.3dm (20.0 MB)



(Pascal Golay) #14

Hello - in Top the split goes right through what’s left of the sphere poles - that’s a difficult intersection. V6 gets it right …


But if to divide a curve the simple sphere, then there are no problems. The problem arises after changes of CageEdit.