Issues with mirroring

Support Modeling
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1

Hi guys,
Never really got into modelling humans and rigging etc until now, and I’ve hit a snag. This could be a bug, or something I’m doing wrong. It seems to happen on both V3 and V4.
I’ve had to split the model, mirror, merge, and re-weight-paint multiple times so far.

I have a model. It is symmetrical, cos it was made from a mirror. Several nasty things have been happening though.

  1. I select a point on the centre line and select select side of active, and things look OK.
    Older4a
    Older4a1920×1057 764 KB

Then I hit select mirror, and I get the selection below.

Older4
Older41920×1057 693 KB

Not sure if it is related, but earlier I was trying to sculpt with mirroring turned on, and the side I was sculpting was moving OK, whilst the other side was literally turning inside out. I also had moments where it swapped the vertices from the left to the right, completely destroying the mesh.

Is there some way to clean this mess up?

I have cut the model in half, re-mirrored, merged, checked for doubles, re- weight painted, re rigged, tried to tweak something for a shape key or a pose key, and suddenly the model is a mess again. This is the third time around, and it’s getting tiring.
Any suggestions?

Matt

2

not a 100% sure on this but the sculpting problem sounds a lot like you might:

A. Not applied scale / All transforms

  • Select object in Object mode > Cntrl + A > Apply Scale or just Apply All Transforms

B. Flipped Normals

  • in ‘Overlays’ drop down menu tick 'Face Orientation & see if you have red squares facing outwards, if you do just hit A, Shift + N & should fix it

That’s all I could think of, usually these two are the usual suspects when it comes messing up mesh functions.

3

The uncomplete selection of the other side most happens because the model is not symetrical… waht i wonder is why some part of the original selection is still selected (will not happen even with extend enabled)…

Anyway: if you do not insist on symetry the ICtrl Numpad + will select the other part.

4

Thanks guys,

Pretty sure there are no flipped normals. I’ll check for scaling issues.

The model should be symmetrical, as it was made from a mirrored half of the original. (This issue has happened several times in sequence. )

Is there any chance it could be because the model originated in a V2.8 file? Has the vertex ordering changed at all?

The same issue is also manifesting itself with shape and pose keys. - The head is separate, as it is asymmetrical, so I made a pose key of it, modelled the eyes closed, without using the mirroring, re-applied this to the original, and found that not only were the eyes closed when the key was NOT applied, but that one eye closed and opened fine, whilst the other turned itself inside out.

Matt

5

I’d say give the scaling & normals check a try, aside from that, maybe select your entire model & merge vertices by distance, maybe you have some rogue verts that snuck their way in while modelling & now they’re messing with the systems…

As for the V2.8 file, tbh I have no idea.

6

If you can’t solve the problem well, please share the blender file.
It seems to me that there is an axis problem, but I can’t tell exactly from the image. :slightly_smiling_face:

Are you using Mirror modifier… :thinking: