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Rigging question

polycounter lvl 9
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soulstice polycounter lvl 9
Hey guys,

I've made some proportion changes(scale/moving verts) to a current model that has already been rigged. My question is do I have to re-rig this now? Because I notice once I jump back into the skin modifier the bones do not correspond with the mesh when I move them? Any help would be appreciated, thanks for you're time!

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  • Eric Chadwick
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    You need to change the bone lengths to match. Go to the bind pose, turn off "Always Deform" in Skin, then use the Bone Tools to change the bone lengths (if you're using Max bones), or Figure mode if using Biped. Then turn Always Deform back on. Should work.

    Did you non-uniform-scale the mesh outside of sub-object mode? A bit more involved if you did, but still solvable.
  • Rob Galanakis
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    I assume this is in Max.

    Go to Advanced Parameters rollout, save out your weights.

    Delete the skin modifier, reposition the bones, apply a new skin modifier and add the proper bones, then Load the skin weights (just hit "Match by Name" on the skin dialogue).

    I really should write a script to do this more quickly (including saving your skin modifier settings).
  • Mark Dygert
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    It depends on what type of editing you did? Most of the time you're ok to move verts, but not remove then add verts. If you just moved them around you should be ok to do what Eric suggested.

    [Useless Max Trivia]
    Each vertex is given a number, the weighting info is stored by this number whenever you go back down in the history stack and remove or add verts it renumbers the verts causing the skin modifier to apply the old weight table to the newly numbered verts. This is why it dorks out if you add/remove verts. Some times you can get around it by applying the edit poly modifier on top of the skin modifier and make your changes, but sometimes it won't. It depends on the kind of edits and how deep they are.
    [/Useless Max Trivia]

  • Rick Stirling
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    Rick Stirling polycounter lvl 18
    ^^^ bake the weights before saving them.

    I've written a script that does this, it saves hours when dealing with a lot of characters.
  • Mark Dygert
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    Hey Rick, I haven't tried and I'm not in front of max right now other wise I'd try it, so I'll ask. If you bake/save then go back down the history stack and add/remove verts, can you load the baked vert data and have it come out ok? That would be some handy voodoo if it works.
  • Rick Stirling
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    Rick Stirling polycounter lvl 18
    Vig - I don't honestly know, it's worth a shot. I suspect it's won't be overlay happy though. Non baking is fine if you have really good envelopes, baking is great with no vert changes because it works on the vert level, loading the exact same weightings.
  • Rob Galanakis
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    Whoops sorry I thought the OP meant changing the proportions of the skeleton.

    If it is just moving verts, try it and see if it works (it should). Otherwise there are ways, like Vig and Rick have suggested.

    If you need to change significant geometry (but not the sizes), you can always duplicate the mesh, perform the changes, and Skin Wrap it to the original mesh, then Convert To Skin.

    One thing I have to give to Max is that its skinning is very robust and flexible (even if I don't think enough of it -or max in general- is exposed to maxscript). You are usually able to change anything you want after-the-fact and not have to do significant work to fix it. I haven't used the new Mayas but 7 and before this was very difficult. Not an excuse to be sloppy (ideally the mesh and bone placement would be completely final before you start skinning) but game development is not a perfect process...
  • Eric Chadwick
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    Vig, Skin Wrap and Skin Utilities can be used to basically do the same thing, allow you to adapt weights from one vert count to another. The latter lets you do exact matches (same count) or adaptive.
  • Mark Dygert
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    oh yeah skin wrap good idea, I mostly just use that for cloth and cloth drivers. I'll have to check out Skin Utilities, I haven't used that before thanks for the tip wink.gif
  • Eric Chadwick
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    Sure man, what comes around goes around.

    Kind of the same limits for both methods. Like Professor420 said for Skin Wrap, Skin Util is also limited to similar positions for pre- and post- meshes. Skin Wrap uses ray-casting, Skin Utilities uses radial distance, kinda cool. I've also used the position-matcher in Skin Or Die, but it's not so robust.
  • soulstice
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    soulstice polycounter lvl 9
    Eric I tried what you mention with turning off always deform adjusting and turning it back on. Worked like a charm!

    Thanks alot guys!
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