Using a different meta-rig for rigify?

[alex_d]

I'd like to use Rigify on my imported models, but with a slightly adapted meta-rig.

I know how to enable rigify on import, but as far as I can see this uses the standard meta-rig. I want to use my own adapted version. Is this possible to do automatically?

[ThomasL]

No.

Depending on what modifications you want to do, it may be easy or difficult to make it doable. Import for rigify now consists of two steps:
1. Import the metarig.
2. Apply Rigify and make some changes to the output rig.
What could be done is to split up that process into two steps, so you can make modifications to your metarig before applying Rigify. However, there is no guarantee that the second step would work on a modified metarig. Some changes will be taken care of automatically, e.g. extra bones that are children of the original bones. A new bone that inserted in the middle of the hierarchy, i.e. as the parent of an original bone, will lead to problems.

[alex_d]

Well, the meta-rig I want to use is actually a combination of the regular one + pitchipoy's advanced rig.

What I did was basically cut off everything from pitchipoy's metarig under the face bone, and then joined that to the headbone of the regular rig.

I did this because the regular rig is easier to set up for Unity's mecanim system. But, I really need the facial bones too, so I combined the two. I managed to generate a fully functional rig as if it were one of the originals like this, so that shouldn't pose a problem. (And I would always use this specific custom rig for any other model I make)

[ThomasL]

OK, I have now split up Rigify import into two pieces.

If you select Rigify in the import options, the new option Finalize Rigify appears. If this is disabled, only the metarig is imported. The second step is to explicitly rigify it, which is done with a button in the MHX2 Setup Panel also called Finalize Rigify. Inbetween you can modify the metarig as you please. Whether the last step will work with your modified is another matter. What I have tested is that it works with a unmodified metarig.

[alex_d]

Oh wow that was fast! Thank you very much. So I'll download the mhx importer for Blender again, I assume that's all you've edited?

[ThomasL]

A couple of bugs appeared when I tried this after actually having added a bone. Fixed now, but if you downloaded yesterday's version, you need to download it again. And yes, only the importer is affected.

[alex_d]

Hmm, I'm not sure if I'm missing something, but I can't seem to find where to edit the meta-rig?

I checked the finalize rigify checkbox, but once I import it shows all the rig-controls as if it were already generated, but I can't find the meta-rig in the outliner or in any layers either.

I also don't see the finalize rigify button in the MHX2 panel... apologies if I'm missing something obvious

[ThomasL]

Hmm, I'm not sure if I'm missing something, but I can't seem to find where to edit the meta-rig?

Blender has a lot of tools for editing rigs and vertex groups. The intended workflow is this:
1. Import the meta-rig.
2. Add bones and vertex groups with Blender's standard tools.
3. Rigify the modifed metarig.

This is what I can do with a reasonable effort. Not sure what else you expected.

[alex_d]

Sorry, I think I might just be misunderstanding the whole thing, I'm still relatively new to Blender and 3D stuff in general so bear with me please. I'm not entirely sure how this automatic process is supposed to work, allow me to explain my understanding:

For me, the meta-rig is this thing (which I get through pressing shift+A)

http://i.imgur.com/3PIcmf1.png

Which I then properly place over my model, add new bones, etc. Then I press rigify and I get this:

http://i.imgur.com/cjZXW7H.png

This last screenshot is also what I immediately got when importing the model with Finalize Rigify enabled. So to me it seems like the metarig is already being rigified anyway.

What I was hoping to do was to see and edit the rig like in the first screenshot upon importing the model, add bones etc. But I don't see where/when I'm supposed to do this in this process.

I'm also not seeing the 'Finalize Rigify' button on the mhx2 runtime panel though, so maybe something went wrong?

Thanks for taking the time to do this (and sorry for not getting it t_t)

[ThomasL]

You get a modified metarig when you import the MH character with Rigify and not Finalize Rigify. This rig has extra bone for deformation and the meshes have vertex groups already set up. Then you can add extra bones and vertex groups. When you finally press the Finalize Rigify button, you get a rigified rig with the extra bones. The picture below illustrates the process.

If you press Alt-A you only get the default meta-rig without vertex groups, and you need to weight the meshes yourself, which is a lot of work for each character. The Finalize button does not appear, because the script really needs the modified metarig created by the mhx2 importer in the first step.