Faces invisible after extrude

I encountered this now a few times and I don’t know whats wrong. Maybe I’m just missing something.

I created a 2 dimensional object and shaped it as I needed it. Then I UV mapped it. After that I went back into Vertexediting and extruded all the vertices to create the second half of my object. The strange thing now is that all the faces are invisble when I go into textured view. When I look at it in solid viewmode, it looks ok. I went to the UV mapping again and textured the faces, but they were still invisible. I have to select each vertex making up a face, then delete this face, select the vertices again and then create a new face, and then it works. I don’t understand why though. I also tried to recaluclate the normals and it didn’t help either. Also flipping the normals for these vertices doesn’t make the faces to show up. If I look at the model in textured mode, it looks as if there were no faces at all.

Any idea whats wrong? I got the impression that this only happens when I extrude after UV mapping, because when I create a new untextured object, and extrude some vertices the faces behave normal.

Your faces are facing wrong way I guess. Use ctrl+N with all faces selected in the edit mode to recalculate normals outside of mesh.
Or…
in UV Face Select mode, in the Texture Face panel you can hit the TwoSide button. This way the texture will be on both sides of face.

edit: sorry, I didn’t read your whole post at the first time.
I had similar problem with normals in plane. I did recalculate normals but it couldn’t help - in sculpt mode the Add mode was sculpting holes, while Sub bumps…
I’m not sure what I did to solve this.

Maybe some faces are duplicated? Sellect whole mesh and hit the remove doubles button.
The normals are facing inside of mesh for sure. Recarculating them should works…

Thanks. Two Side is not an option in this case, because I need to export my models to Doom 3, and then it would also do this, which might cause framerate delays. I’ll try that duplicates next time, maybe that helps. Recalculating the normals didn’t change anything, but I already tried this as it was the first thing I thought of. :slight_smile:

i think the issue is in extruding after mapping. the vertices and faces you create from extruding are not mapped, really, and you need to do an unwrap to create uv coordinates that are at a different location from the originals…so they map to some non-zero area of the image. It is safer to model you whole mesh THEN do the unwrap/uv tex.

Yes. That seems to be the case. I noticed that the UV for these hidden faces, are all in a single point kind of. But unwrapping didn’t help because they stayed where they are. Normally I do the modelling first and then the UV mapping, but in this case I simlpe forgot. LOL. I looked at the front screen, saw that my model was finished, and totally forgot that I only modeled the front part. :stuck_out_tongue:

But in some instances I can’t avoid it. For example, I modeled something, UV mapped it, and then I didn’t like the final result, so I removed the offending part and started again on these parts, to make them better. As long as there are a moderate number of faces involved, it’s not a big problem, but if you have more then it gets cumbersome. Would be great if this could be fixed somehow.

Hi,

what went wrong when unwrapping the additional geometry? When I did it (adding geometry after initial unwrap) the new faces inherited their UV-coords from the adjacent faces. Did you make sure you pinned the right faces? A screenshot might help to nail the problem.

Regards