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KakCAT
01-01-2011, 12:19 PM
Hello, happy new year everybody :)

I'm a coder trying to write a converter from Kinect data (via OpenNI) to BVH files in order to use them in MotionBuilder. I've reached a point where the data seems to be correct (for torso and legs) however I'm absolutely unable to correctly map the BVH into a character done by me in 3dsmax.


As you can see, my char has one stance and the equivalent BVH has another different one

http://img191.imageshack.us/img191/2068/testkhj.jpg (http://img191.imageshack.us/i/testkhj.jpg/)

it's worse with Edward :) His legs are bent 180º at the start

http://img12.imageshack.us/img12/8519/test2ri.jpg (http://img12.imageshack.us/i/test2ri.jpg/)


I've used correctly some BVH (the CMU database), so I think the problem is in my data (I don't know why because the BVH skeleton is shown well) or maybe I'm not doing the T-pose correctly.


Could somebody please take the BVH and check if it's working for him? If not it'd be very valuable if he could point me where the problem is (i.e. some limbs rotated 90º, or whatever it is). I really don't know how to use motion builder (I'm on a 30 days trial right now and it's day 2 :^) )

http://rapidshare.com/files/440236383/bvh_and_naming.zip

(the BVH is always facing negative Z, so my first step in T-stancing it is rotating it 180º to face positive Z. Only the legs have correct data, I'm having some problems with the upper body part
)

Many many thanks!! :)
Buexe
01-04-2011, 10:24 PM
I have quickly checked your bvh file and it seems to me that this is not a joint structure like you would typically use for a mocap file. For example there is a chest joint and then both arms are pchildren of this joint. Typically there would be clavicle/shoulder joint inbetween. So I guess taking a look at the joint hierarchy could be worthwhile but it is just a quick guess. hope that helps a least a little bit.
KakCAT
01-06-2011, 11:32 AM
I have quickly checked your bvh file and it seems to me that this is not a joint structure like you would typically use for a mocap file. For example there is a chest joint and then both arms are pchildren of this joint. Typically there would be clavicle/shoulder joint inbetween. So I guess taking a look at the joint hierarchy could be worthwhile but it is just a quick guess. hope that helps a least a little bit.

Hi Buexe,

thanks for taking the time to check the BVH :)
What you say makes sense, I'll try to match the skeleton from the CMU mocap BVH files, it will probably lead to better results.

I've been playing around with MotionBuilder and BVHs and I've realized that the BVH skeleton must match the character bones almost exactly to get good results. I've almost fixed the legs but I haven't fixed the arms: Will try to match the typical mocap skeletons as you said
The problem is that every character and BVH I generate is unique, making the process too complex. I'll work on it :)

(I have some questions but I'll open them in another thread)
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01-06-2011, 11:32 AM
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