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ishotton

OpenGL Exporting Bones and Joints from maya

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Hey guys, i found this tutorial on writing an exporter, but i was just curious if there is anything that is different that I may need to do to export Skinned animation information. http://www.gamedev.net/reference/articles/article1906.asp I didnt know where else to put this thread, but since im working in OpenGL i would throw it in here. Thanks in Advance :)

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Yes. Exporting a full character (MFnCharacter) with animated joints is abit
of a hassle if you are new to the maya dag/dg graphs. But it is quite possible.
I have code for it lying around somewhere and will try to dig it up once I have some time (leaving for family activities).

One thing that I know is a bi"#¤tch is that if you do "delete all by type/history" on your scene it gets quite hard to find the bindpose of the skeleton. I do believe I did find a way todo it at last though.. .but make sure you dont delete
the history of your first test scene.

Will try to get back in here with some code in a couple of days.

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MFnCharacter is only useful if you are using character sets, and in general i've only seen about 30% of people who actually use them. The character sets and clips themselves are something i'm not a personal fan of - it causes immense check in hassles when multiple people are using version control (i.e. 10 people work on one file, vs 10 people working on 10 files). The other obvious side effect is that the files can easily become corrupt and you'll lose all of the animation data. It's safer to keep anims seperate and use file references to the rig.

deleting history on a skin doesn't happen in the real world. Doing so will *always* destroy the skinning info (i.e. no skinning will actually work, since in effect, the skin clusters are part of the geometry's history). This will not affect the bindpose info on the bones though (you can still see the bindpose node in the hypergraph - just traverse along from the bindpose attr of the joint). (you can of course delete the non-deformer history which will leave the skin data intact).

MDagPaths are also *very* handy to extract transform matrices (without joint orients and rotation axes). Otherwise, check the DG node reference for joint's to figure out the matrices you need to multiply together. (and be warned that transform and joint nodes are evaluated using different equations)

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