Imported FBX is missing all triangles

I have a model that on import into Zbrush is missing all of it’s triangles. The quads display normally.

It does not have this in Blender nor in 3Dcoat.

I have checked in Blender & it is not that the normals are flipped, the triangles truly appear to be missing.

Any ideas? I attach a screenshot & am happy to share the model if it is of use.

Thanks in advance,



looks for me that the polygon normals of this triangles shows inside of the model.

Please have a look to this thread:


Thanks @HarryBee.

The problem persists after enabling the ‘Double’ display property.

It oddly appears as though just these triangles for some reason have not been imported.

Anything else I could try?

Hi @arumiat

Did you try “Close Holes” in “Tool > Geometry > Modify Topology” ?

1 Like

Hello @arumiat

Close Holes as ZBer mentioned should fix this easily.

My guess as to the reason for this is that you have imported a mesh with ngons (polygons with more than 4 points). Ngons cannot exist in ZBrush at any time. The .obj import process will give you an option of how you want to handle this situation, but the FBX import does not. It will insert edges to turn 5 sided polygons into a quad and a tri. The tris created by this may end up as holes in the mesh.

Your image is not very high rez, but if I zoom in very close I believe I can make these 5 point polygons out, and can see where the edge has been inserted to force quads and tris:


If this is the case, I would recommend either eliminating your ngons prior to export, using obj format instead, or just repairing the mesh as suggested above.

Good luck! :slightly_smiling_face:

I took the mesh into Blender & isolate any faces with more than 4 sides and indeed, I found the offending Ngons!

The close holes option worked, although sadly I lose the UVs for these faces.

Thanks for your help! :slight_smile: