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Re: please someone give me a clue?????!!!??

Posted: Thu May 05, 2011 12:28 pm
by NaturalPoint - Mike
Body is completely different.

For body motion capture you use multiple cameras to create a 360 degree field of view around a volume contained in the center. Also, you're looking at 5/8" markers spaced significantly farther apart than the 4mm facial markers.

Re: please someone give me a clue?????!!!??

Posted: Thu May 05, 2011 3:32 pm
by Seth Steiling
Hi Alessia,

A few thoughts, after watching your video and reviewing the data you sent in to support...

Regarding your custom marker template:

- While it is possible to create custom face templates, you are adding a pretty significant number of extra markers. This still might be doable--I don't know of anyone that's added this many markers, so I can't confirm--but in the event that you challenge the system with a more difficult point cloud, you're going to need to augment it with more tracking capability if you want to have the best chance of being successful with your custom arrangement.

- I can't tell which marker size you are using, but if you're tracking lots of markers, it would probably be best to go with the smaller 3mm markers.

- You certainly will want to use more than the minimum camera count. Sounds like you're going to try 12 cameras--this should give you a much better chance of succeeding.

- Narrower FOV lenses--like the 5.5mm lenses we sell with face packages--will offer improved resolution, which can greatly assist in resolving the small markers used in face tracking. It looks like you're using 4.5mm lenses, which might still work, but will not perform as well as the 5.5mm for this particular type of mocap. (If you're using 3.5mm lenses, I would definitely recommend swapping out, as they are not designed for face.)

- Camera aiming becomes especially important when you're stressing the system. The more you challenge it, the less margin you have for error. In the video (@ 5:10 or so), it looks like many of your cameras are not aimed directly at the actor's face--in some cases even cutting off part of the markers completely. You should re-aim accordingly, as others here have recommended.

- The cameras also appear to be spaced too far apart, and potentially a bit too high/low. This is indicated by the steepness of the angle at which several of the cameras are seeing the markers:

Image Image

If you were to bring the cameras closer together, or add additional cameras in between the inside and outside pairs, this should help. You want as many cameras as possible to see most/all of the markers, from slightly differing perspectives--especially at lower camera counts. You need at least a foot or so of distance between them, with 2 feet often serving as a nice distance, but 4-6 is probably too much. At that point, they don't share enough common coverage of the markers, which can result in the kind of tracking you're experiencing.

Hope this helps! While all of the above is especially important if you're taxing the system with custom, high marker point clouds, it all holds true when using a stock template as well.

Re: please someone give me a clue?????!!!??

Posted: Thu May 05, 2011 3:47 pm
by Seth Steiling
[quote=Alessia]Seems that we can have decent point cloud only at night, we never read nowhere that we need totally black room to see some markers but its ok[/quote]
Just a quick note on this--it's not that you need to be in a completely dark room. Most ambient light is totally safe. But open windows, in particular, can be a problem because of how much IR the sun pumps out. Halogen lamps can be just as bad, especially without an IR filter over the bulb. A dark room isn't needed, but you can't have IR streaming into your volume from external sources.

Re: please someone give me a clue?????!!!??

Posted: Fri May 06, 2011 3:12 am
by Alessia8086
thank you very much for the help, were' gathering all those information and trying to get the result we aim, at the moment weve try a configuration with 10 cameras ( we will ad 2 more )
as said before we have try with a 37 markers combinations plus a black background behnde actor to avoid any kind ot reflection/obstacle in the view behinde, so far the result its pretty decent, we're going to test the custom solution today to see if they are understanded, one single question, we've export the first "test" and ive noticed that fps shows 100 and if i change that to 24 the speed of the playback still its hyper fast, where i should set the correct frame rate?
thanks Again we will post some video soon..

Re: please someone give me a clue?????!!!??

Posted: Fri May 06, 2011 9:42 am
by Seth Steiling
The capture speed should have no impact on how fast the data plays back in Expression, so I would recommend keeping it at 100 FPS. However, it is possible to adjust the playback speed at the bottom of the Edit section. Make sure it's set to 100 as well.

Re: please someone give me a clue?????!!!??

Posted: Sat May 14, 2011 3:32 am
by Alessia8086
ok so....at the moment only the 37+4 marker setup its working with 10 camera used, no way we can have a setup with 53 markers to work in any conditions at any point, 37 markers its way not enough so, any clues, configuration as been fixed, black cloth behinde actor, no sun in the scene, 10 cameras, 3 mm markers and still nothing...

Re: please someone give me a clue?????!!!??

Posted: Mon May 16, 2011 4:20 pm
by NaturalPoint - Mike
Could you send the project, template, and pt2 files for the 53 marker setup to support@naturalpoint.com for some analysis?

Re: please someone give me a clue?????!!!??

Posted: Tue May 17, 2011 2:27 am
by Alessia8086
yes im sending it now

Re: please someone give me a clue?????!!!??

Posted: Tue May 17, 2011 4:22 pm
by NaturalPoint - Mike
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