Proportional Editing and X Mirror [WORKAROUND DISCOVERED]

I know this has been talked about before but the fact that proportional editing does not work with the Mesh Options X Mirror is a major issue. It is a huge problem when it comes to making Shape Keys that you want to keep symmetrical. :frowning: The lack of this simple tool makes creating these shapes extremely difficult.

Is this on anyone’s radar to fix in upcoming releases? I’m shocked that more people are not complaining about this. Is there some kind of workaround that I’m not aware of?

I’ve seen the video of the guy that hits the g key and gets symmetry but this no longer works.

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Is there some kind of workaround that I’m not aware of?

Grab brush with symmetry enabled

That doesn’t work… at least not in 2.63. It looks like it’s trying to do something (the verts move a bit) but they certainly don’t mirror themselves. :frowning:

I’m going to bump this one more time. Does nobody else care about this? It’s taking an excruciatingly long time to make my shape keys.

Darned tootin’ I care. Just having the same trouble myself.

Didn’t want you to think you were all alone on this.

Found something…

Delete half the mesh and add a Mirror Modifier, turn off X-Mirror, turn on Proportional Editing.

This worked in a test-case. Now to see if it works on the real deal.

So how does this work once you decide to apply the mirror? Maybe all the shapes need to be built before rigging? I’m not sure this will work. I’ll have to try it but it will mean starting from scratch with the rig and all my weight maps.

Using the mirror modifier didn’t work.

The only workaround that looks promising at the moment is using 2.58a, which I happened to have on my hard drive. But, it’s a lot of work. I appended the mesh into an empty file in 2.58a, but it came in as wireframe in Object Mode. The faces were missing. I tried just filling them in, but apparently faces that show in Object Mode are stored in a different order post-bmesh, so the mesh looked fine while I was in Edit Mode adding the faces, but when I switched to Object Mode: instant mess… No, you read that right, not ‘instant mesh,’ but ‘instant mess.’

So, I deleted half of the appended mesh, started a new object (circle) and used the magnet tool to snap vertices to the appended object, extrude to add the next loop, and so on, thus recreating it as a new 2.58a (non-bmesh) object. I’m still in the process (it’s taking a while) but I’m hopeful that once it’s done, I can then build the Shape Keys in 2.58a and just append the final object back into 2.63a.

As far as weights go, if you do have to rebuild your mesh, I believe there is a way to transfer weights from one mesh to another. You may have to recreate the mesh completely–vertex for vertex–in 2.58a, but as long as the vertex count is the same, the weights should transfer over. I know that’s not what you wanted to hear, but it’s all I’ve got.

And I’m still not sure if this process will work for what I’m doing either. My mesh doesn’t have weights painted on, so it’s not going to be as much work as what you’ve got going.

I’ll post again as soon as I know more.

If you create your model from the start using the Mirror Modifier then you can paint weights and when applied they will be good for the bone assignments on each side after you are done. At least this worked for me, when doing rigging.

X Mirror is a PIA and needs to be fixed.

As far as doing shape keys for faces, you need them separate anyways. If you want them to be created the same, the mirror modifier and Proportionate is the only way to go. It does work. Or has worked for me in the last months I have been using it.

Just make sure you enable Clipping and the Merge Limit set to 0. For vertices that move away from the center while editing, simply occasionally turn off prop and reset them. Then prop back on and continue. When finished, recenter the center verts and apply the modifier.

That should work for you.

For a face shape it will be more tricky to get the left and right sides set up. I have not done that exactly yet in Blender. But it is something you want to have so you can control each side separately. If someone has done that before please share the workflow. I will give you the theory of how I’d try it, but it is not confirmed through practice. It would involve likely duplicating each shape and Naming one Left and one Right. Then splitting the model up, then removing she left shapes from one and the right shapes from the other and then merging them again. Have not done this, just a theory.

@Richard: Which version are you using? I can’t imagine how you’ve got X Mirror working with Proportional Editing, at least, not since bmesh. If you’ve got a secret way of getting it to work, please share.

@tommywright: Not a lot of luck, even with 2.58a. I finished the mesh and started x-mirror/proportional editing and things are acting strange. Only some of the mirrored vertices are moving; most aren’t. Strange since it was apparently working when 2.58a was first released.

That was the thing I hated about going from 2.59 to 2.60 :frowning: They really need to get that fixed! It’d be 10x faster if you could do mirroring with prop. editing! I wonder if this is a problem that someone could make an addon for :confused:

No I never said that. :eyebrowlift: I use the Mirror Modifier. X mirror us useless in with prop. In fact because it is such a touchy tool anyway I almost never use it. I always use the M.M. In some rare cases where it works, I use X mirror. But for creating things from scratch if I need mirroring/creation and editing in real time I use the M.M.

Just in case it gets lost. Mirror modifier also works with weight painting and it automatically mirror the weights when you apply it. At least it did in the last version I did rigging on 2.62 or 3 I think.

@Richard: I tried using the mirror modifier, but what stopped me was not having control over the model’s mid-line. It was getting cumbersome having to realign/scale it back to x=0 every few seconds while editing. Do you just put up with this or do you just keep the influence of Proportional editing so low it doesn’t affect the mid-line? I tried the latter and it was really slowing me down. Of course, considering how much time I’ve put into trying to find a work-around, I could likely be done by now. I think I’m obsessing.

@fergoblender: Even though these tools are both pretty deeply buried in the C code, it should be possible… Theoretically, at least. Nothing says you can’t reproduce the behaviour of X-mirror in Python or even the behaviour or Proportional Editing… even both.

The strange thing I’ve run into now:

Yesterday, I decided to go back to an earlier version of Blender (pre-bmesh) and recreate my model, then add the shape keys and try loading/appending it back into the current version of Blender. This road is fraught with danger!

  • A bmesh model can be loaded into a pre-bmesh version of Blender, but it will have no faces.
  • Faces can be added and look fine in Edit Mode, but in Object Mode, it’s obvious the model’s vertices are stored in a different order because the mesh turns into a mess.
  • Recreating the model from scratch in an earlier version doesn’t seem to help. The combination of X-mirror and Proportional Editing still works unpredictably (versions 2.57b to 2.62).
  • What’s really annoying is that this combination of tools works on David Ward’s Edward model in earlier versions of Blender (2.57b and 2.58a). But, if I create another model in the same file as Edward, these tools won’t work on that model.

The conclusion I’m left with is that combining X-mirror with Proportional Editing hasn’t been working predictably for quite some time, perhaps as long ago as the first 2.5 version. I read somewhere that a major rewrite would have to be done in order to fix it. Perhaps this is one of those things Ton has in mind to fix after Mango is released.

Let’s hope so.

  1. A bmesh model can be loaded into a pre-bmesh version of Blender, but it will have no faces.
    When you saved your blend file did you enable the ‘Legacy Mesh Format’ tickbox in the Save As options. Then open that blend in pre-bmesh version. It usually works ok.

Thanks for the tip, Richard. Yes. It DID work. I didn’t have to rebuild the model…

What’s more, a bit more experimentation allowed me to find a way for X-mirror and Proportional Editing to work together in a predictable way. All I did was enable X-mirror BUT NOT Topology Mirror.

So at least now I have a process:

  • save the model with Legacy Mesh Format turned on
  • load into Blender 2.58a
  • turn on Proportional Editing
  • turn on X-mirror (but NOT Topology Mirror)
  • create the shape keys
  • load back into 2.63a

Voila! And eureka!

Thanks to everyone: Richard C., Richard M., tommywright and fergoblender!

I do believe this thread can be marked “Solved.”

Not really solved but thank so much for figuring out the workaround! I’ll have to try it as soon as I get my weights back (I added a bunch of geo to my character and messed him up a bit… not uncommon for me).

Again, thank you so much for posting the workaround… this was driving me CRAZY! :spin:

@tommywright: You’re very welcome. I suppose my motivations were pure; I needed it myself, but happy to share.

And you’re right; Workaround Discovered is far more appropriate. I didn’t know that was an option.

I am glad you got it solved from a “workaround”. But just so you know, yes, and yes. I deal with it and also when necessary, move the influence so it does not affect the center line. When doing larger edits to the model it is an issue and the only way it works is to recenter the lines. That has been true in any modeling I have done over I am not sure how many years going back to LightWave even. Not sure how it works in Modo.

But if it were me, I’d choose M.M and its shortcomings over X mirror every time, especially of it involved a workaround. It is far more solid, flexible, and you can change geometry as well. Not to mention it works with Weights which is a plus.

Just me 2C. But if you need to work that way, good that you got it to work for you. :eyebrowlift:

This guy does something super cool to create the 2 sides of the face. He uses vertex groups for each side keeping the center 50% of both side… just watch the video around 14 minutes in he does this. Very clever!