Any one know of any links to info on really, really cheap mo-cap solutions? Cheers

I don''t know of any, but I know that the software and hardware cost a ton.
However there are a few sites that outsource already done motion capture data.
A search on google should turn them up...

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Black Hole Productions
http://bhp.e-chrono.net/
Resident expert on stuff
max621@barrysworld.com
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Dark room, couple of precisely position camcorders, actor in dark (preferrably skin-tight) clothing with white ping-pong balls stuck to critical joints and flexors. Record. Use video capture software to acquire positions of white balls and locate on 2D grid. Cross reference mutliple images, voila! Homebrew motion capture.

Interestingly, this is essentially what House of Moves, etc do. The difference is that they have about 12 evenly-spaced, high-precision laser cameras that work in lit environments, props and expensive actors. The data from the cameras is buffered during a shot and then fed to a computer for collation into a single 3D animation (with error correction and noise filtering).

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Thanks to Kylotan for the idea!

quote:

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Original post by Oluseyi
Dark room, couple of precisely position camcorders, actor in dark (preferrably skin-tight) clothing with white ping-pong balls stuck to critical joints and flexors. Record. Use video capture software to acquire positions of white balls and locate on 2D grid. Cross reference mutliple images, voila! Homebrew motion capture.

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Conceivably possible, but not without a lot of thorns.

• Synchronzing the frames.
  
• Even worse: frame #23 on camera #1 doesn''t necessarily match with, say, frame #26 on camera #2. More likely, it matches with frame #26.677 on camera # 2.
  
• Camcorders don''t necessarily provide shutter or aperture control. Just how long of a shutter exposure did you get on frame #26? How about that motion blur you did get? Lots of motion blur. You don''t want motion blur for this.
  

Good point. At the very least, it''s a cheap approximation (and explains why the professional quality stuff costs so much).

Several people at my university have done some interesting homemade attempts at motion capture..Probably the most publicized was Project Earthlight, where somebody utilized a web cam and track the (slow)movement of a neon colored lightsabre..Tracking specific colors works.

My ex-team leader did the same thing with tracking colored boxing gloves, still with a webcam, so it isnt necessarily as slow as may be thought.

So, I suspect with some flourescent clothing and time to burn by writing web-cam and networking software, one could get some low-yield automated mocap going. Would probably take a lot of work to get it working really really well, though.

[edited by - krikkit on May 10, 2002 2:18:27 AM]

Thanks for the replies guys...

I wonder if I can convince some of the fresh-faced fellows in my local Computer Engineering department that this would make a good project for their final year?

hmm.. just had an idea (lack of sleep is a great tool).. I wonder if I can avoid the need to have multiple cameras synced up exactly by using just one camera and some kind of mirror set up... say have the actor stand side on to the camera and then have a mirror set on a 45 degree angle to display the front view simultaneously... similarly you''d need an angled mirror above them to get the top view... it certainly wouldn''t be a perfect solution (or very portable!) but it might work... sort of...

hmm.. I think I''d better go to sleep and read this post in the morning to see if it makes any sense...

I have a couple of webcams sitting around so I thought I might give this a try. However i cant figure out how to record more than 1 stream (using the Quickcam software that came with the camera) I cant start 2 instances of the program.

I tried the webcam app from Game Programming Gems 2 but I couldnt get any picture at all.

Anyone know howto get both cams to work?

assuming they are usb cams and they both got the proper drivers installed. try using the filter graph to manually add the capture filters yourself. you can then route this to a compressor then file writer or just the video renderer. though compressing the data may be too intensive and i am unsure if mulitple web cams will work properly. i only have a single web cam so i cant readily test this, but i know its pretty easy to create the filter graph.

with some work you could even implement this in a realtime app if you can get the video processing fast enough (need very fast cpu and good algo niether of which i can help you with). this may be better then storing the data to disk because disk usages of compression of the video may slow things up as well.