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ajax
10-30-2004, 12:08 PM
hi,

can someone explain what is "Motion Capture", and how it is related to LW in particular, and animation in general???
thanks

Dave Davies
10-30-2004, 12:39 PM
"Mocap" is a method of animating your characters by external means - that is, not keyframing. Data is collected for each main joint, - neck, shoulders, elbows, hips, knees, ankles, etc., and key body parts - head, spine, pelvis, etc. That data is then attached to your animated character, assigning it a position in 3D space, at a particular time.

There are several ways of collecting the motion data - some systems use radio telemetry, others use optical. some use a complete body suit, others just put sensors on the joints. Some connect the actor to the computer with wires, others are wireless. The more sensors - the more data. Basically, they all just collect data for a certain XYZ position at a certain moment in time.

Let's say you want to capture some karate moves. Your actor puts on a suit that has data collectors at the main joints and key body parts. Everything is set to 0,0,0, and you startt o record his moves. Voila. Actual karate moves.

There are preset mocap files available from BVH and others that have walk, run, dance, fight, etc., motions ( and much, much more), saving you the expense of the mocap system.

The "Poor Man's" motion capture achieved by strapping ping-pong balls or something equally visible on the actor's key joints, and videtaping their motions. Then, with the video in the background, you line up the 3D character's joints with the ping-pong balls.

There's two schools of thought on which is the best method - some people prefer keyframing to mocap - it's been said that mocap gives more realistic motion than keyframes, but it takes longer to clean it up. I can't speak to that, but I think that the big kids like Disney, Pixar, etc., combine the two methods.

Dave

ajax
10-30-2004, 03:18 PM
thanks dave,

you put a very complicated, and difficult (to a novice like me) subject in perspective for me.

lotta smart guys here. i am impressed. i wish there were more of you all.

ajax

dean080580
10-30-2004, 08:09 PM
well just to simplify,
Its just the process of animating a character without the usual manual method but a quicker one that is by capturing the movements of real life forms,,lets say humans and then tranfering the movements in terms of computer data and assigning it to a completely modeled human character thus creating an animation sequence.

hope this can help

cheeerssssss

ajax
10-31-2004, 01:44 AM
dean

thanks for your help.

cresshead
10-31-2004, 08:19 AM
pixar hand key their animations...the do not load up motion capture files onto their chracters ....they do however "act out" the motions to either a mirror or tape it via a camcorder and use that as reference when rotomatting the 3d character in 3d.


lw has no data thinning capability when loading/editing mo cap data so you'd be better off using motionbuilder to thin data out so you can edit it before using the data in lightwave.

character studio for 3ds max can data thin and convert mo cap to footstep driven animation where you can edit it as though it were hand keyed...i'm hoping that lightwave can one day take a look at this and do somthing similar as this would really be quite useful.



steve g

ajax
10-31-2004, 09:13 AM
thanks, Steve

cresshead
10-31-2004, 12:04 PM
since hearing back from splinegod about how difficult it is to handle motion capture files nativly in lightwave i'm tryng to find a workable solution by using character studio in 3ds max to load and "data thin" the mo caps then export a bone rig to drive my characters in lightwave as i prefer to render in lightwave as it looks so much better and is simpler to setup a render...

i'm using fbx export from max but "biped bones" are not supported so i'm working on a way around that shortcoming of the fbx file format by driving 3ds max native bones via the biped rig instead of the actual biped bones....
i'll let you know it it works or not!

problem solving!...fun fun fun!

steve g

SplineGod
11-07-2004, 02:53 AM
pixar hand key their animations...the do not load up motion capture files onto their chracters ....they do however "act out" the motions to either a mirror or tape it via a camcorder and use that as reference when rotomatting the 3d character in 3d.


lw has no data thinning capability when loading/editing mo cap data so you'd be better off using motionbuilder to thin data out so you can edit it before using the data in lightwave.

character studio for 3ds max can data thin and convert mo cap to footstep driven animation where you can edit it as though it were hand keyed...i'm hoping that lightwave can one day take a look at this and do somthing similar as this would really be quite useful.



steve g
Rotomating is a quick n dirty (but easy and effective) way to copy motions.
Lightwave actually does have tools for thinning and filtering keyframes. What it lacks are tools to easily scale the data to fit the character. :)

SplineGod
11-07-2004, 02:57 AM
There's two schools of thought on which is the best method - some people prefer keyframing to mocap - it's been said that mocap gives more realistic motion than keyframes, but it takes longer to clean it up. I can't speak to that, but I think that the big kids like Disney, Pixar, etc., combine the two methods.

Dave
The reason mocap is used on pretty much every feature film that has lots of CGI characters is cost. Theres just no way that LOTR or Star Wars :AOTC for example could be done without mocap. Its just too much work to be animated by hand. :)
Mocap is never perfect so its important to have a rig that allows the motions to be tweaked or overridden. :)

prospector
11-07-2004, 05:09 PM
The "Poor Man's" motion capture achieved by strapping ping-pong balls or something equally visible on the actor's key joints, and videtaping their motions

Yep.
Did a step by step how to on another thread