Hi,

I've a questão about what kind of transformation houdini does in the rotation channels when I import a BVH file in my scene. No problem about the animantion, it is working right, but the rotation channels has nothing to do with the rotation channels in my BVH file. The mcbiovision utility does some kind of quaternion transformation?

Thanks

The main reason for this is because the transform/rotation order required by Houdini in the Bone objects are usually different from the order specified in the BVH file. I forget now, but the coordinate system convention may also be different.

By default, no additional quaternion transformation is performed. So if you had flipping in your mocap data, that will still show up when you import into Houdini (ie. animation will be faithfully reproduced). If you specify the -i option however, then IK chains are generated using the skeleton, effectively ignoring the twist rotation of the joints from the .BVH file. In that case, the result can be different because it's just matching the IK goals.