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Blender Armature Export

Posted: Mon Dec 19, 2005 10:42 pm
by wallclimber21
Hi All,
I'm in the procress of learning Blender and Ogre at the same time.

At this point, I'm able to export simple models with materials and skeletons from Blender to Ogre.

Now, for *really* simple animations, everything works exactly as expected. that is, arms move how they move in Blender etc.

However, once slightly more complex rotations come into play, the export doesn't work at all. Basically, my poor little man starts swinging his arms ways he was supposed to.

Now looking at the .skeleton.xml file, I see that the rotations of bones in the keyframes are not given with quaternions, but in x,y,z vector format. My assumption is that Ogre does keyframe interpolation with those instead of using quaternion interpolation, hence the weird results.

Could this be the reason? Or should I look at other reasons? Any ideas?

Edit: I *am* using IM_SPLINE and RIM_SPHERICAL in my animation settings. What I'm seeing is that very small rotational 'wobbles' in Blender are going completely overboard in Ogre.

Thanks,
Tom

Posted: Mon Dec 19, 2005 11:37 pm
by xavier
What versions of each?

Posted: Mon Dec 19, 2005 11:50 pm
by wallclimber21
Blender version: 2.37a
Ogre: 1.0.6

By addition additional keyframes, I'm more or less able to limit the wobbling. Obviously, Blender and Ogre have different interpolation algorithms. The one of Ogree has some overshoot that's not present in Blender.

Tom

Posted: Tue Dec 20, 2005 12:17 am
by xavier
How many keyframes were you using? 2?

Posted: Tue Dec 20, 2005 1:17 am
by wallclimber21
5 keyframes. I increased it to 12. Basically one every 3 frames...

Tom

Posted: Tue Dec 20, 2005 2:00 am
by nfz
Are you using IK constraints and if you are did you bake your actions prior to export?

Posted: Tue Dec 20, 2005 2:07 am
by wallclimber21
None of those. No IK constraints. No bake.
(In fact, I've been avoiding anything IK like because I wasn't even sure it's supported by the exporter...)



Tom

Posted: Tue Dec 20, 2005 2:15 am
by xavier
You don't export the IK because Ogre doesn't do it. You use IK to make your life easier during posing, but the exporter just puts out the keyframes.