Why faces are transparent?

What does it mean to have transparent faces?

I have two identical boxes but one of them is showing transparent faces, the transparent one is a mesh and the other one is made out of polysurfaces. see images. I changed modes (rendered, ghosted, x-ray, etc) I need to 3d printing them, I have a more complex geometry than these boxes and I need to understand what’s causing this issue.

Any help is welcome. Thank you.

Back Face sample case.3dm (49.0 KB)

Hi Sergio- try UnifyMeshNormals on the mesh box. (Rhino does not draw the back faces of closed objects and in this case one of the face normals is pointing in. - use testMeshDir to see this)


Thanks Pascal,

that did it ( UnifyMeshNormals & testMeshDir ). It was fixed. I guess I can still apply this command to a more global / complex mesh without causing further issues.