Hey guys,
anyone know how to clean mocap data in quick way ?
now I have .c3d/.csm mocap data, i use 3DSMax’CS and MotionBUilder to clean it. but the
jitters almost can’t be clean out in CS. I find it’s a slow way and don’t work right. so,
any suggest is welcome!
to Headless:
i had read some your suggest about mocap and MB, and learn much through that. if you don’t
mind, could you give me some suggestion about mocap data cleaning?
thanks
Well, not sure what version of MB you have, but I’m gonna take a guess that the help didn’t change much between versions.
Help -> Motionbuilder Help
Webpage should pop-up (At least it does in version 7). Look under the contents for “Motion Capture” and expand this section by clicking the box next to it.
The “Optical Motion Data” “Magnetic Motion Data” and “Motion Capture Devices” sections are the one’s you’ll most likely want to examine.
This information is a start. Give some more details about what you’re trying to do and what devices you’ve used to capture data and we might be able to help you further.
-b
mummey, thanks for your reply
I use MB 7.0 pro now, and had studyed the MB help document on mocap . i want to know how to clean up mocap data in a quick and effective way.
we use Vicon 612 to capture motion data. so we can get .c3d and .csm motion data. Now, I use 3dsMax’s CS to clean it. but I can’t familiar with it, and can’t stand its motion curve edit mode. so could you help me…
thanks a lot for your reply
guans
Since I don’t have Motionbuilder on this computer, any tips I give you will be from memory, so you might have to do some digging to find where some tools are.
Ok, so what i’ll do with mocap is clean up the marker data as much as possible actually in Vicon. After i’ve labelled everything up, i’ll run a pipeline on it to fill gaps with rigid body, filter the curves with a butterworth filter to try and get rid of any jitter (this doesn’t work all that well i’ve found), and then trim tails. I’ll then look in the 3D view and at the curves to see if I can spot any jitter. If I see some then there’s a bunch of different ways i’ll look at sorting it, but usually i’ll either select the section that’s jittering and run a weighted average filter on it, or i’ll delete the area with jitter and relabel it with say, rigid body or associated. It’s really just a matter of learning the tools and then coming up with your own solutions to fit the circumstances.
Once i’ve done all that and exported it to C3D, i’ll load up my pre-made actor setup, and import the C3D file by dragging and dropping it into the scene. If you do Options, then Import, it should essentially merge over your existing marker setup and your character will switch to the new motion. If you don’t know how to set up an actor to be driven by markers, and then a character to be driven by an actor, that’s all in the Motionbuilder tutorial files.
When that’s done, there’s a few things you can do before you plot the character from actor input to control rig input, that’ll save you problems later. First of all, if your character and actor don’t match up perfectly, you want to look at the Reach T, Reach R and Pull sliders in the character control window. With these you can force the character to match up to the actor based on body parts. You’re best to make sure the feet and legs match up as well as possible so that walking and floor contacts need alot less work. The upper body and arms you can make a judgement call on, depending on the motion: For example, if the actor is smaller than the character you won’t want to try to match the upper body perfectly cause otherwise you’ll get a crooked spine.
You should also look at the drop down menus in the Character Settings tab while the character is still on Actor Input. I forget exactly what it’s called but i think it’s something like ‘Roll Extraction’, and you want to turn all the checkboxes for each of the body parts in there on. Basically that stops any rogue ratations in the limbs and can help reduce jitter by quite a bit. You might also want to look at the Motion Reduction sliders, as sometimes you might, say, not want to move the shoulders around quite so much, so you can do that in Motion Reduction. When you’re happy with that, plot the motion to the control rig.
From here things are very much down to the individual file. Chances are your hands will be like paddles, your feet will be messed up, and you might well still have jitter. Besides that you might want to make other small little changes to the motion, like make a kick go higher or make the head look it a different direction. These are all things that you really need to just learn the software for, as they all depend on the individual situation.
What i’d suggest with hands is that you create a file with a relaxed hand pose in it, save out just the pose, and then you can merge that in to any future mocap files and apply it on a new layer to your character. You’d still need to animate the hands but it’s often a better starting point having the hands looking relaxed rather than flat and unnatural.
Feet are always tough to sort out. The most straightforward way of fixing them is to just do it by making manual readjustments on a new layer, but that can be time consuming and it still doesn’t ever plant the feet perfectly. There’s another way of doing it that a guy at my work came up with that involves ploting the foot data over to auxiliary effectors then deleting the translation keys on the auxiliary effectors at the points the feet should be planted, but that sequence is like an article in itself, so i won’t go into it.
Other stuff I might do to get rid of any remaining jitter, is mostly in the curve editor. I usually sit my filters window alongside the curve editor and then go through and nuke most issues by selecting problem areas and then using a mix of peak removal, smooth, and key reduction filters. Also, you can sometimes solve issues with unwanted rotations that don’t seem to shift by plotting to skeleton, deleting your control rig, then plotting to an IK only rig, but that’s not always the best solution. Of course there are times when there are jitter errors or unwanted rotation that just refuses to go no matter what you do, so in those cases you may just have to delete the animation on that limb and re-animate it.
Another quick tip: Sometimes if there’s too much motion on say an arm, a good way to reduce it is to create an auxiliary effector at the wrist and constrain that to the top of the spine, then play with the auxiliary effector influence. Other times it’s best to just solve all these things manually, by working on a new layer.
As I say, in the end you really just have to learn the software and employ whatever tools you think will help solve the issue, but for now this has hopefully given you some ideas to work with.
Headless, thank you very… very… much. i will try it later today .
I got a correct way in cleaning mocap data from you, .i hope one day i can thank you in any way.
THANKS…
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