Remesh by union getting rid of interior mouth bag


Im modelling a head, and polygrouping its various sections to get nice zremesher results. Ive currently got. mouth bag that is also polygroup as well.

Annoyingly I still have a couple of extra subtools that I still want to combine and blend back into this mesh, the only problem being, that as soon as I combine them together I loose the interior mouth bag.

The route im using currently is to combine the folder of subtools and then do a merge by union - but this annoyingly merges away the interior elements :frowning: .

Am I doing something wrong or is there another technique someone could recommend?

I really don’t want to have to repolygroup the mouth bag as that was a bit of pain

thanks for any help!

Hi @nickholl

I couldn’t say from the vague information here. A picture of your topology and the subtools involved would be worth a thousand words.

Eliminating redundant or overlapped geometry is a key part of this functionality.

The Gizmo Deformer Remesh by Union fuses the topology in that single subtool. Make sure all the subtools you wish to fuse have been merged into that subtool. Otherwise use Live Boolean to merge the topology in separate subtools together.

Make sure all the meshes involved are closed, watertight volumes with a degree of thickness. This wont work with 2D meshes or open volumes. If the process reads a section of mesh as open it will attempt to close it. If your mouth cavity topology is not welded to the head topology, it will read it as an open volume and the process will close it. If the head mesh is an open volume at the mouth, the process will attempt to close that mouth opening and remove the interior geometry. Your mesh should look like the demohead.zpr mesh from Lighbox. Open at the mouth but welded to the mouth cavity to form a single closed volume.

Good luck!

Sorry to be so vague. Ive attached some images. So the heads all watertight. Ive shown in the interior mouth bag (purple polygroups) by hiding the head polygroup. Ive also attached an image of the mouth bag all smoothed down to show how its welded to the head.

Does remesh by union naturally want to close the mouth like dynamesh would?

thanks again for your help

smoothed mouthbag

Hi @nickholl ,

Ok, your problem here is that your lips are intersecting. Intersected geometry is fused by the process, and everything inside will be eliminated. You’ll need to open up the lips to a neutral position so they are slightly parted, and then pose them after the geometry is stable, just like working with a T-Pose. The “Move Topological” brush can be useful for moving one lip while only minimally affecting the other.

The only reason to have an articulated mouth cavity is if you wish to be able to pose the character with open mouth poses. So the problem in this case is that you did not create the character in a sufficiently neutral position for that purpose like a T-Pose to complete your modeling before posing.


doh - never mind. Ill try and bear than in mind in the future. The reason I’ve got the mouth bag is just to that the join in the lips looks more natural than if it was fused together.

thanks for the help!