Problem When Displaying Mesh in Render Mode

Check for yourselves: Great Mesh.3dm (162.2 KB)

As you rotate you will see some faces appear and other disappear. Shaded view shows a hole in those places.

Besides that bug, Im needing help fixing my meshes. I cant even fix a freaking rectangle it seems.

All I wanted to do is to cap my original mesh so that it would not have naked edges. Seems that solely operation is impossible to do in Rhino. I dont know why you just cant create a new mesh, like you would create a surface from 4 vertices.

Anyways, I checked the mesh. Got the erros. And applied the needed commands to fix those errors:

-Degenerate faces - Fix with the CullDegenerateMeshFaces command.
-Zero length edges - Zero-length edges typically are the result of degenerate faces. Fix with the CullDegenerateMeshFaces command.
-Non-manifold edges - Use the CullDegenerateMeshFaces command and then fix with the ExtractNonManifoldMeshEdges command.
-Naked edges - Naked edges are allowed, but cause problems with rapid prototyping. Use the ShowEdges command to help find them or set the display mode to paint them a different color. Try the FillMeshHole, FillMeshHoles, or MatchMeshEdge commands to remove naked edges.

Went from having a nice uncapped rectangle to an abomination, but Hey! At least its a “good” mesh right?

The shading errors were due to non-manifold edges playing havoc with the mesh normals. You can make a couple new tris on the top of the box using 3Dface and Vertex Osnaps but you’ll still have little gaps elsewhere in the mesh. I think the polys were drawn without snapping to vertices originally. You’ll also need to use UnifyMeshNormals to get the shading/normals all facing the right way after you Join the faces you make. Here’s a sample. 3dface_sample.3dm (209.3 KB)

Alright, thank you