Hi houdinists,

We are running into a problem that maybe the community can help.

We are currently making a tool to bake Rigid simulations using textures in our engine. We already have a same similar tool currently working in Maya.

For each animated piece we are trying to bake the rotation using the attribute “orient” (quaternion from dop import) inside a texture. However we've noticed that quaternion's values from frame to frame adds sometimes a 360 degrees in XYZ axes in the values baked.
That results weird rotation flips on interpolation.

Houdini seems fine with that data though, including when the baked rotation are re-injected as a unit test.

Anyone here did run into that issue? Also I was curious about how baking rotation was handled in RBD to FBX Gamedev tool.
Cheers

Hey brosty. Are you converting from quaternion to euler? Euler flipping is pretty common because of how rotations are expressed differently between the two. cgwiki has a file and comments on the problem here.
http://www.tokeru.com/cgwiki/index.php?title=HoudiniChops#RBD_filter_high_frequency_noise [www.tokeru.com]