Hello everyone,
I have one VERY OBVIOUS problem exporting animation to Montionbuilder OR 3DSMAX. The whole body rotate randomly and suddenly. This character was rigged with CAT in 3DSMAX2014 and was Exported to motionbuilder 2014(CIQ_Mocap1.fbx). I tried to load this character in ipi Mocap studio and export it via FBX format. But after I loaded the file exported from ipi Mocap studio. The whole body rotate randomly and suddenly.
I tried to import the fbx file exported from ipi Mocap studio to 3DSMAX. The whole character also rotate suddenly and randomly.

Please see my attachment.
(.iPiMotion files and fbx files, the screenshot video)

I am looking for your answer,please.

...

3DS Max is bad at export/re-import back to itself from other programs, even if was exported from 3DS Max originally, this has been a known issue with Max for a long time, especially if you change the original CAT bone naming profile that Max uses.

Try to export just the skeleton for 3D Max from iPi and then map it to your character rig, you can save the naming profile used and re-use if for any further characters with the same bone naming conventions.

It could also be a Parent node issue, your character uses a Dummy and not the original Parent node created by CAT, but I didn't create it, so I don't know why the Parent node was switched to a Dummy that doesn't control the Global positioning of the character and it doesn't seem to be set at the Global 0,0,0 coordinates anyway, which is where any reference node should be.

The BVH exported file from iPi doesn't have these issues when applied directly to a biped, so it is just something in the export/import back to 3D Max of that character.

There are tutorials on bone mapping for CAT on YouTube if you are unfamiliar with the process.

Good Luck

...

Thank you very much for your detailed reply，Snapz. The developers of ipisoft have solved my problem via Email.
Thank you developers of ipisoft again. The problem was only caused by the exporter of Ipi Mocap studio they said. Nothing wrong with my CATrig or 3dsmax system or Motionbuilder. I hope will the updated and stable version release soon.

...

OK Great!

I don't generally export characters from iPi for import into other programs, I do export a few specific test characters into FBX Review to check the motions though.

At any rate, glad they solved your issue.

Good luck in the future.

...