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CgWannabe999
07-26-2011, 05:04 PM
What is the 'best' way to take a messy BVH file from the CMU set, and clean it up?

I've been going over the 'Foundation Learning Tools' tutorials, and there are certainly many ways to modify animation.

The Story method seems most flexible.

I'll need to have f-curves to do much cleanup, and a characterized bvh doesn't have f-curves.

I understand using the Butterworth filter for basic noise.

But, there are places where a foot will move18 inches in one frame and then back again (a bad data point?). What's the best say to delete this bad data for the frame for that joint?

It's also hard to see what is happening with just the BVH data, the way MB represents it - and easier to see with a skeleton or control rig?

There are places where feet seem to move up and become part of the leg. Could this be a rotation issue fixable by changing from Euler to Quaternion - and can MB do that?

I watched the tutorial on using optical data with an 'Actor'. Can an Actor be used to 'clean up' BVH data if something has become 'flipped'?

Should I just try to convert it to FBX so that I can bring it into a Story and clean it up in Story mode?

Thanks!
bclark
07-29-2011, 05:52 AM
I'll need to have f-curves to do much cleanup, and a characterized bvh doesn't have f-curves.
??? The characterized BVH has f-curves if you plot the animation to the control rig.


But, there are places where a foot will move18 inches in one frame and then back again (a bad data point?). What's the best say to delete this bad data for the frame for that joint?

Plot to the rig, then just delete that fame of data from the motion

It's also hard to see what is happening with just the BVH data, the way MB represents it - and easier to see with a skeleton or control rig?

You can always add a demo character to drive with the data to do a quick check on a mesh vs. skeleton.

There are places where feet seem to move up and become part of the leg. Could this be a rotation issue fixable by changing from Euler to Quaternion - and can MB do that?

Motionbuilder can fix flipping with filters or you can check the fcurve and fix it by hand.


Should I just try to convert it to FBX so that I can bring it into a Story and clean it up in Story mode?

I would stick with layers and out of story for what you need to do at the moment. if you need to you can just bake the current take in to story and use it then plot it back to the main timeline with out having to save out the file to .FBX first.\

Hope that helps,
Brad
CgWannabe999
07-29-2011, 03:40 PM
There are places where feet seem to move up and become part of the leg. Could this be a rotation issue fixable by changing from Euler to Quaternion - and can MB do that?

Motionbuilder can fix flipping with filters or you can check the fcurve and fix it by hand.

Thanks for the great advice!

How do you fix flipping with filters?

I saw one tutorial
Foundation Learning Tool\12_Apply_and_Correct_Motion_Capture_Data.flv
on using an Actor and 'rigid bodies' with optical to fix flipping. Could that technique be used with BVH?

BTW - there's an excellent technique in this thread for batch converting BVH to FBX:
http://area.autodesk.com/forum/t58138

Thanks!