Thinking of buying Optitrack system, please advise

[renderer]

Hi
I'm trying to make an animation with Daz/Poser characters and I'm looking to purchase a motion capture system to help me achieve this. I understand the 12 camera system will cost approx $10,500US with accessories like suits and tripods.
I've a couple of questions before I make such an expensive investment.

I live in the Caribbean but I'm willing to travel this year to an event/exhibition where I can see a demonstration. Any ideas on the closet or biggest event this year?

I currently use Daz, Poser and Lightwave 7.5
What should be my next animation software investment. Compatibility with Daz/Poser is a must. Not really worried about LW compatibility as I only use it for scene rendering and basic modelling. Would CD4 or XSI have any advantages with DAZ or OptiTrack integration/pluggins?

Reading the forums I've noticed some people complaining about shaky motions if the movements are slow. Is this true and can it be easily rectified using software/hardware.

Thanks

[VincentG]

I believe the next trade shows, that we currently have plans for displaying the system, are -

GDC - San Francisco - March

Siggraph - New Orleans - August

Currently the Arena software streams realtime data into Daz, via plug-in. Once the data is imported into Daz, you can save it, and export it via Daz, how you like.

I'm not aware of many issues, with shaky motion, with a good calibration, and the latest version of the software.

[bsteagal]

868

I have an 8 camera system which I use with Daz/Poser (mostly Poser) and 3ds max. I don't have any issues with shakiness, but one thing you will encounter is that every model is slightly different and every program deals with bvh differently. Poser seems to have the most amount of issues because of their bvh implementation.

Once you keep this in mind, and know how to correct whatever problems you do encounter, the system works wonders. No mocap system is perfect.. even 120k Vicon systems have issues you have to work around at times. 10k is a bargain in mocap..

and, like Vincent said, a good calibration is essential.

[dtaylor112]

[quote=868]Hi

Reading the forums I've noticed some people complaining about shaky motions if the movements are slow. Is this true and can it be easily rectified using software/hardware.

[/quote]

I was atually just getting onto the forum to mention this. I use Poser have the Optitrack 8 camera setup, I see that when the User/Skeleton just stands there (to create a generic stance) the torso jerks randomly, not often but that seems to be part of the "slow movement shakes" - maybe the NP team can address this or let us know if WE are doing something wrong. That could be the case.

Overall it's a pretty decent MOCAP system but when you look at the alternatives like Vicon (6 camera special for 50k last time I checked) this could be a worth while option based on what you want to do.

[bsteagal]

868, Koan

The only time that I've encountered shakiness is when your calibration is not great or if you have something that is generating noise when capturing (for example, in tradeshows when you have a lot of light issues, people walking into the view of cameras with something reflective in their clothing)

Another thing I've noticed that can cause problems is loose fitting suits or improperly positioned markers (markers shift, causing problems) or when your pc or laptop is being taxed by other software while you are capturing. Make sure that nothing else is running on your pc (disable virus scanners, anything else that is extra.

[farstar]

How about feet not staying on the ground plane at all times? you know like feet being off the ground or passing through the ground plane.

[bsteagal]

FarStar

Some of it may be how you have the foot and ankle markers positioned, sometimes it can be the character itself, I've noticed that poser sometimes has a lot of issues due the way that it imports bvh files. They have their own implementation of bvh (basically how it scales the data to the poser skeleton. Make sure you have IK turned off in poser and limits is unchecked before bringing in the bvh file.

Feet going thru the ground plane or lifting up could be the foot itself, or the hip rising... I have some characters that I use all the time that have this issue (mainly toon characters from 3duniverse) I have a python script that was given to me by the creator of the characters to correct this somewhat... (what happens is that data that is mapped to the hip is not scaled correctly, so that the hip translates widly on xyz, like if it was a bigger character)

One good way to tell this is by going into the xyz of the hip where you notice the issue and see if it is not this that is moving instead of your feet.

I usually end up manually fixing feet issues anyway...

NO mocap system is perfect, (especially optical systems) there will almost always be issues that have to be fixed or data that needs to be cleaned. Expensive systems like Vicon have the same exact problems, so it is not confined to just Naturalpoint. You have to get to the point where you learn how to fix any issue that crops up... (I will admit, Poser is a bear to fix sometimes, and seems to have a lot more problems than other software packages)

I've been at tradeshows where Vicon had so many problems setting up and getting good captures in comparison to Naturalpoint that it was downright funny (considering that a base 6 camera Vicon is about 50k)

One thing I've been playing with recently where you can really see how badly poser imports things is by using the DAZ plugin.. In poser, I can have a character that has the feet bent wrong and back and shoulder problems. When using the DAZ plugin (where it is streaming live) you don't see any of this... Besides, you can adjust markers and things like that and see the differences rather quickly...

[farstar]

Bryan thank you for the info on this I will be sure to look into it and see if I can fix the issues I have seen. I am not using poser but Max but I am sure it is user error on my part being new at this.

[bsteagal]

FarStar:

What problem in max are you having? I use it with max a lot also.. you having issues with the plugin or when importing bvh onto the biped?

[farstar]

When I did the test with the capoeria motion cap file provided by optitrack I noticed in my renders out of max that the feet were off ground plan and passing through ground plane but then when i look at the actual motion capture rig its feet are doing perfect so i am sure it was a mistake on my end being a new be with this stuff. But all in all the motion capture looked amazing in action on my model. Would love to show it but the project is under wraps at the moment. Thanks again for the tips to look for I am sure this is what the issue was that was causing the problem.