View Full Version : Mocap to Cat sytem tutorials needed.

05 May 2012, 10:52 AM
Just wondering if anyone has or knows of a good tutorial for importing mocap data to 3dsmax cat rigs. I've found a few online, but all found seem to pull erors, not import the mocap fbx into the scene and be written for max 2011 when trying them out. I would prefer soemthing set up for Max 2012 to cut out any confusion on where and what to use.

thanks for your time.

06 June 2012, 09:30 AM
Hey zwicker,

I am looking for similar information as all the workflows I have tried have come up a bust with an unknown system exception error cropping up with the capture part of the process.

My process so far has been that I have used vicon blade to capture, then I have used a combo of max and motion builder for clean up and for obtaining BIP and BVH formats. These plug into BIPED almost well enough but there are some discrepancies with limb spasms and the BIPED not quite moving as far as the original FBX when performing things like bending over etc. I assume this is down to FK/IK differences and proportions but this is not the worst thing as adjustment layers sort this out.

What we should be able to do is load the mocap directly into CAT but the farthest I've been able to get is to receive a bunch of CAT boxes I assume which animate but the "capture" feature refuses to work. We should also be able to capture animation from any rig which so far I have been unable to perform.

I'm not saying it's a bust but I do really hope I've missed something simple and this workflow is possible.

I've posted a thread over at Area and awaiting a reply, hope this comes in useful.


07 July 2012, 04:11 PM
Some questions:

1. You getting the .c3d data i'm guessing from blade, building the actor characterizing and solving to a skeleton in motionbuilder?

2. In max your loading this solve onto a biped. Does the biped need bvh data that matches its hierarchy exactly and if so did you export the biped to motionbuilder, characterize it and solve it to the vicon actor?

3. CAT's capture system is pretty raw, basically all it does is store the transform difference between its joints and a target set based on a mapping file:

'' 'targetJointName' (matrix3 transformOffset)

4. If your going from vicon to CAT why does it need to be loaded into biped?

So basically - the mapping feature of CAT right-click on the joint selecting 'map to' can be pretty damn frustrating. I infact wrote my own as its its a pretty standard format to right.

Things that ARE crucial is in your BVH creation - generally joint translations only happen on the root so you need to make sure translation is specified if you want joints other than the root to move.

The capture process is hierarchal, i.e if you write a tool to write the mapping to a file, it needs to be hierarchal - else it may crash.

CAT's capture is vanilla - its process however isnt so you have follow it by the book. When you follow its mapping process your target and source skeletons (BVH, and CAT) need to be in the T, A or default pose.

The other thing that can kill it is mapping joints that are under a system - e.g. limbs and spine, neck joints - just map the hubs, hands, ik targets, pole vectors - and you should be on your way. It'll plot it onto the fk anyway.

The rule is CAT is a rig basically not a skeleton in capturing so map its controls not its joints - unless there purely fk eg fingers, toes etc..


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07 July 2012, 04:11 PM
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