Solid visual issue in shaded mode

Rhino
1

I’m seeing an issue with one particular solid model where individual surfaces are effectively see-through but rhino confirms the solid is closed. The effect also occurs in rendered mode - but not with other models. Would anyone be able to advise what is going on?

Thanks!

Rhino visual issue2
Rhino visual issue21630×1064 90.2 KB

Rhino visual issue
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2

I would try try the following sequence:

  1. Make sure your absolute modeling tolerance is set appropriately.
  2. Explode the polysurface
  3. Run RebuildEdges using command default settings
  4. Join

Do you get a closed solid polysurface?

3

Thank you - that solved the issue.

4

Cool.
My guess is through the process is building and editing the polysurface, a tiny overlap or loop ended up in a surface edge curve. When it was Joined one surface had it’s normal direction reversed makint inside out. The command sequence cleans up the surface edge curves, removing the little problem. Then when the surfaces are Joined again, the surface normals are oriented properly.
This doesn’t happen often, but often enough it’s a handy cleanup process that sorts the problem quickly.

Cheers