mocap and biped

sir-knight

here's a question about mocap data and biped, I've never used any mocap data before but I've got some and I'd like to try it out. The example provided with the package has a very complex rig, mainly with twist links in the rig, how important is it to retain the exact same rig from the example to my own work? Do I have to use the same rig or can I simplify the biped from 3 twist links in the arms to 1?

using max 8 of course.

Rick Stirling

The mocap data will only be for the underlying biped I suspect - all the other bones are very likely to be procedurally driven so you should be fine.

sir-knight

okay cool, I've spend a couple hours going through the mocap tutorials and bringing in the data for my biped, however it alters the biped I have in scene to match the one in the mocap data (1 finger instead of 5 on my biped)And it seems to change some proportions in the biped pieces, specifically the legs, will this be a an issue when I actually have a rigged character?

Eric Chadwick

Depends on the data format. I think a .BIP file will overwrite your existing structure. But if you re-import the source motion format instead, like BVH or CSM, then you can fit it to your own structure.

Takes some finesse to import raw data, been awhile since I had to do it. You use biped's FIG format to control how the motion is translated to your rig. It doesn't work great with extreme changes between captured structure vs. custom structure, like human bone lengths into extreme character lengths. You'll also need to generate footsteps to re-lock the feet, otherwise they'll slide around.

You might get some interpenetration and such, like if the character has a big belly but the mocap performer didn't.

sir-knight

There doesn't seem to be a tutorial in the max reference about this so I tried this:

Saved the biped .fig file

went to import mocap data .bvh file.

added under talent definition > figure structure my .fig file

And it throws up an error saying the structure in the bvh does not match the structure of the figure and refuses to import the mocap data.

Is this the proper way of attempting it or is there another method (one that works :P)

thanks.

Eric Chadwick

As I said, been awhile since I've done it, but in the Contents tab of the help file click on these...

1. character studio:
2. File Formats and Index of Procedures
3. Procedures
4. To import a motion-capture file

sir-knight

thanks, seems I figured a way to edit the biped after importing, but not adapt the data to the existing setup. I'll dig around some more.

Eric Chadwick

Yeah, typically you try to iron out the whole pathway before committing to a particular rig. But then things change during production, so often you have to force something to fit an existing setup (or re-do a ton of work).

sir-knight

it shouldn't make a whole lot of difference on the current project as there's so few verts on this model that I can just weight by hand and hopefully the joints are in the right places. Actual movement will be very limited, but for future use, I'd really like to know the proper workflow, especially when things get more complex.


edit:

I just tried this method:

bring in my biped as a temp, load the raw mocap data, save to bip, load my rig again, and reimport the bip to the scene... seems to use the proportions now

Eric Chadwick

Yeah, I think they mentioned something like that in the Help.

OK, yeah, here it is...

[ QUOTE ]

Tip: Use a biped that does not have a mesh attached to it with Physique. Import motion-capture data with the idea of then saving a BIP file that can be used for any character. If skeletal scale information is loaded from a motion-capture file, a mesh with the Physique modifier applied might deform unnaturally.


[/ QUOTE ]

sir-knight

btw, there was no mention of using skin anywhere in the tutorials that I saw, would it be alright to use skin instead of physique or will that make it self destruct?

Eric Chadwick

Skin is better all around. Physique hasn't been improved in years. Development has continued on Skin, it has good tools, better workflow, good scripting support, etc.

Either can be used, depending on what your game exporter supports. Good luck!

sir-knight

doh, what did I hit? I had key frames and the mesh was responding just fine, then I must've hit a key or something happened and the biped is now animating as before but the mesh doesn't respond. Envelopes are still there and verts are showing up with weights as before.

Using skin with biped on max 8.

edit:

I will also add that the light bulb is ON in the modifier stack before anyone thinks I hit that accidentally

Rick Stirling

Always deform is off?

sir-knight

it's on

sir-knight

arrrggg... I just wasted a good 45 minutes...

there was a sub object mode selected underneath in editable poly.... apparently you have to exit out of it by clicking 6 or just select the top of the edit poly stack... then close it and go back up to skin. wtf o_o

thanks for the help I'm still wtfing over it though.