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edenxiii

Quaternions, Maya, and X files

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I posted an issue I had with exporting from Maya a little while ago, and Gents gave me some pretty useful advice, but there's still one huge problem, and I don't think this one's so simple to fix. It turns out that when a model uses IK in Maya, the solver uses euler angles to resolve the bone's rotations. This becomes a problem because DX reads rotations as quaternions, which explains all the weird jittering, popping, and geometry twisting a lot of folks --myself included-- have been getting. So the question is: does anyone know a way around this? Is there a way to tell Maya to use quaternions for IK, or has someone recompiled an exporter that fixes this? What about conversion apps like PolyTrans or Deep Exploration? Will they help? Is there an open-source/free equivalent? Big ups to anyone that can help. Thanks in advance.

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Funny what a good night's rest can do; I've solved the issue, and I think posting the answer here will help at least a couple people. As I said, DX has a problem with euler rotations, so before setting any animation keys you need to make sure Maya uses quaternions. You can set this by going to Window > Settings and Preferences > Preferences and click on Keys under the heading Settings. There's a drop down that allows you to change the math behind rotations: set this to "Synchronized Quaternion Curves."

Another thing to be sure of is that there aren't an miscellaneous transformation nodes hanging around the scene. Open up the hypergraph by going to Window > Hypergraph and delete any transformation nodes you find. This might blarg your bones or geometry, but that shouldn't be too hard to fix. Basically, you're doing this so that everything in your scene inherits only the transform of its parent, which is what the DX expects. Its a good idea to keep everything as clean as you can anyway, since every .x exporter out there dumps the whole scene hierarchy out to file.

Oh, and it seems that the recompiled October exporter is more reliable than the December and newer ones. Problem is, that file's really hard to find these days. Luckily I still have my orignal .rar, and I've already submitted it to Fileplanet. As soon as its up for download I'll post the link here. Hope this helps someone.

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Yes! You're right ^__^

You've found the solution! I've noticed that December Exporter was fixed out, too! Now I've to check if in the new February update Maya exporter changes...

Byez,

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Quote:
Original post by edenxiii
Oh, and it seems that the recompiled October exporter is more reliable than the December and newer ones. Problem is, that file's really hard to find these days. Luckily I still have my orignal .rar, and I've already submitted it to Fileplanet. As soon as its up for download I'll post the link here. Hope this helps someone.


Is there a specific scenario where you are seeing more instability in the Dec04 plugin than the Oct04 plugin? If you have a repro for a particular issue, please mail directx@microsoft.com or reply here and we'll look into it. Improving stability for the Maya plugins is important to us.

Thanks,
Paul Bleisch
WGGT Solutions Team

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Still waiting to hear back from FilePlanet...

In the meantime: Paulble, I wish I could figure out what exactly causes export problems with the newest exporter, but I can't find a pattern. The only consistent problem is with my desktop machine. When I try to gather the animation data, Maya pops up a messagebox about a "pure virtual function call" error, then crashes. I'm pretty sure that this is just an issue with that one workstation, though, as I haven't been able to reproduce this on any other machines.

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