Reapplying symmetry and fixing distorted polys.

I have been using Zbrush to detail my mesh recently. However I get a rather strange error around the eyes. THe vertices seem to go all over the place, and I can’t figure out how to fix in zbrush. The first image is of the obj imported into blender for cleanup. The second picture is of manually cleaning up the vertices, one at a time.Is it possible to use a mesh tool to correct this mistake? I have access to Wing3d, Maya, and modo as well.

Also if say I do fix the one side, like the second image. How do I restore symmetry without have to delete one side and use the mirror modifier? I lose the UV’s this way, and I don’t really want to do that.


Well, the best I can think of for fixing the messy mesh would be to select the area around the eyes and use the “Smooth” button in the Mesh Tools panel (F9).
For the symmetry question: select the “X-axis Mirror” toggle in the Mesh Tools More panel (F9). Of course, your model has to be oriented correctly for the x-axis mirror to work right…

hmm, I think I misinterpreted what you were asking about the symmetry thing.
If you have your UV layout saved in Blender, you should be able to delete one half, mirror the mesh, then select the proper UV mirror option in the mirror modifier panel. you will still might have to do some manual UV pushing after the mesh is reunified, but it should save you alot of time. I’ve used the process myself.

Mesh->Scripts->Mirror Vertex Locations & Weight

The mesh script doesn’t fix the werid eye problem. Is there a certain setting I should be using with that script? The left side is the clean side. How can I delete half of the mesh, and retain the same UV’s? The UV’s are not mirrored. If necessary I will post the blend file.

The Uv’s and the amount of vertices need to remain the same, so I can replace the first subdivision level in zbrush, with this model.

Can you post the blend file?
(which left side? from the viewer or from the face?)

From the viewer


mesherror.blend (510 KB)

Here is the conclusion. The model is not symetrical.
I made an loop to region in order to select all faces inside that area and the result is:
225 faces = 96 (on the left) + 129(on the right)
see the image below.
Obviously the script can’t do anything about it.
So I just got rid of the “bad” vertices inside the eyelids until both sides of the head started to look simillar.
Finally I applied the script I mentioned above a few times and got a fully symmetric mesh with the UV map preserved (see the blend file)
You can now remodel the eyelids area.
By pinning all existing UV coordinates and unwrap the newly created ones you will have to make a minor tweaks in the UV map.


mesherror-fixed.blend (476 KB)

Won’t this be an issue for zbrush though. You changed the amount of vertices. I will test out if it loads into the first subdivision level zbrushwise.

The weird vertices toward the inner part of the eyelid, were for the remainder of the eyelid.Is that better to leave it rounded like that, and do the detaililng via zbrush?

But they were okay until they go to zbrush. I’m not sure how the mesh became uneven vertices, since it was built in blender with the mirror modifier.

I get this error in zbrush.


I am not familliar with ZBrush. Maybe somebody will help you with that.
Try different export options for OBJ from Blender.

Alright, I took a look at your blend and did some experimenting.
I don’t know of any quick short cuts to your issues. However, I was able to delete half the model, mirror it using the mirror modifier. Align the center vertices using “Do Clipping”. Set Mirror U to “on” in the mirror modifier panel (turn on “Final Shadow” in UV editor View Properties, if you want to see the mirrored UV’s. Move your UV islands around to line up with each other, You’ll have to “scale x 0” a couple of the islands to get the middle to line up. Then apply the mirror. The somewhat time consuming part is having to select the island halves in the UV editor and align them. once aligned, however the UV nodes should snap together automatically. Check to make sure the middle of the UV parts are connected, select one half (L) and move it to line up. I was able to mirror, fix the eye area (using Smooth in Mesh Tools, then manually pushing) align the UV, apply the mirror, finish UV alignment, in 30 minuts. So, you won’t be out a ton of time…

Could you post a picture of what your talking about? I’m not sure how to mirror uv’s or what your doing to them with the lining up part.

If nothing else works, it it possible to bring in say the 190k or 700k poly model and somehow extract those detail unto the low poly one in blender? Like by projection.

Sure, no problem.
This overview shows the model with the mirror modifier. Note the highlighted areas.
The UV Editor shows the view properties panel and what should be selected there.
The UV image with the shadow is what your mirrored UV will look like after moving the island in place. Note that the mirror center is center of the UV editor, you’ll have to line everything up, even outside the colored box, then move the islands where you want them after the mirror modifier is applied. You could also scale down and then scale back up later.
Modify the center vertices of your UV islands by setting the UV cursor near the line you want to straighten, make sure the pivot point is set to “3d cursor” the Scale>>x>>0. This will straighten out the vertices. Then move the island until the shadow center and the UV center align. after you have done this for all the islands you want connected, apply the mirror modifier.


I never noticed the clipping option before!?!?! Wow now I don’t need to worry about merge limits and crossing mirrored meshes!?! Would the poly count change after you mirrored it?

Can you alter topology and maintain UV’s somehow? I’d like to have a bit more geometry in the butt region, if possible. If its too much trouble I won’t bother. I think I remember how to restore the different levels of detail with a new mesh. It requires the use of subtools and zproject. This is in zbrush though. Its a shame seems don’t remain on an obj file.

You could do it, but you would need to manually slot in the uv’s of the new faces into the existing uv layout. The painted uv map would then perfectly fit existing topology and almost fit the new topology.

With the eye thing - I’ve found that Zbrush and Blender subdivide UV’s ever so slightly different, which obviously only provides an issue at edges. I turn subdivide uv’s off in Blender and the equivalent setting in Zbrush - forget it’s name. For fixing the eyes now, you could use the displacement modifier on your original mesh and assign it to deform via vertex painting and then ease the displacement off the eye edges.

The poly count will change, if your mesh is not symmetrical to begin with.
You cannot alter the topology without recalculating the UV. Your textures will not come out right. You can pin what you have, add the topology, then recalc UV. That should add the new topology to the UV map without moving the rest. You might have to unpin the new topology and recalc UVs.
Oh, and yes you can use higher detailed models to transfer detail to lower res models. One tool you can use for the purpose is the retopo tool. I know I’ve seen threads around on the topic.

The retopo tool doesn’t really work on my 64 bit version. The points seem to go inside the higher resolutions mesh. Although I don’t know if you can use the base mesh as the topology. I don’t think I have a seen a tutorial for that. If I can generate a displacement map from blender, I can reconstruct subdivision levels in zbrush.

Is the displacement modifier in blender?

@Soter- I tried that but even with every point pinned on each island I didn’t want to change, the uv’s went hay wire.

Unfortunately I’m not very familiar with the retopo tool at all. I only know others use it to restructure mesh. I wonder if there is a threshold that can be changed to keep the new mesh from going “through” the base?

About the UVs: I took a look at your blend and the reason your UVs are going haywire is because you have no seams on the model. If you select “Sync UV and Mesh Selection”, you will be able to select the edges of you UV islands which will, in turn, select the corresponding vertices on the mesh, then you can mark the seams in the 3d view pretty easily. This will allow you work your UV map correctly. You might have to apply your Rotation/Scale (CTRL-A) on your object, in Object mode.

Yes the displacement modifier is in Blender (F9), in the Modifiers panel.
A while back I wrote step by step instructions on how to use it.
Hope this stuff helps! :slight_smile: