When I export from maya to direct X I get twitches on rotating joints

#1

i tried several exporters and noone seems to deal with this problem. Is it possible to be related to use iof iks ? Problem gets more apparent whenever rotations are greater than 90 degrees. Please help !!!

tnxalot

kumpa

#2

I dont think it’s an exporter problem - to me it sounds as if the real-time DirectX code you are using is interpolating the rotations with Euler angles rather than Quaternions. Given any rotation around an axis, you could get to the target rotation by going clockwise or anti-clockwise. normally you would want to go the shortest possible route between the two angles. With Quaternions this is very easy to do, however with Euler Angles it’s almost impossible.

The result is that euler interpolation will more often than not, take the longest route for the interpolation, ie, the joints randomly flip and jitter a lot whilst animating…

#3

I’ve been having issues with the DirectX Exporter for Maya 6.0 (from the December 2004 SDK) as well. The 1st frame is always messed up and my skinning on the end joints of my skeleton are always messy as well and I have to change the Mesh Viewers skinning methode to software for the skinning to look right, but it displaced the model, everything works fine in Maya. I also have to disable all IK and bake the IK animation to the bones to be able to export without crashing. Any help would be appretiated.

Thanks,
The-Shadow-TS

#4

It is probably what robert said but the other way around, maya uses euler angles by default and the most common in dx seems to be quaternions.

In the maya graph editor change the interpolation of all your curves from independent euler to synchronized quaternion and you can see the graphs sometimes go haywire.

The Shadow: I didnt know they had enabled skinning export in the dx exporter in the december release, I have to try that out. Back when the october release didnt have any skinning support I used the exporter from summer 2003 and it seemed to work well for most animation purposes (though it doesnt support stuff like vfvdata for more uvsets etc).

#5

The default blank .fx file created by nVidia FX Composer was messing up my skin.

I also started my animations at frame 0 instead of 1 which solved the 1st frame being corrupted.

Still having issues with my legs acting weird in the MeshView, but the animation looks fine in the nVidia FX Composer and Deep Exploration. Tried to convert to quaternion, among other things, I’ll try it again see if it fixes this last problem I’m having.

Thanks,
The-Shadow-TS

#6

No luck with quaternion rotations either.

#7

nope, Maya calculates all animations using quaternions. The euler angles are all converted to quaternions internally within Maya. If this didn’t happen then you’d have nasty gtwitches when animating. You only need quaternions when you are actually slerping the data. You can store matrices or euler angles and convert to them ‘just in time’…

As for the x format, hmmm. Better to write your own exporter and loader imo.

#8

Hey, I’m starting with the whole directx stuff. I first started loading some old models I had, with some help of the december update turorials. The thing the model loads perfectly but I can’t make the material or texture to work. Where can i find some info about Maya and directx exporters???

Please help!!! i have don’t have much time (have to present a simple phisics proyect in a week)

#9

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