I've just started using DMC and have found certain portions of it to be very frustrating or confusing. I feel like I'm having to spend hours doing things that should be fully automated.

After calibration DMC set my Camera 4 to 0.5m off the ground (in reality it's about 0.9m off the ground). Other camera positions seemed about right once I applied the scale. What do I do here? Do I manually move the camera into position and use that as my calibration data? I tried clicking Calibrate again after moving it manually but it just stuck it in the wrong place again.

I tried tracking and found that the system had a very hard time tracking one of my arms in a relatively simple movement. I was also unable to manually pose the skeleton to fit what I was trying to do. In the video my arm was in front of me, elbow bent somewhat like how you would lift a barbell (palm and shoulder on the same horizontal plane, elbow below). But when I tried to pose it the Inverse Kinematics kept trying to move the skeleton's arm into a motion more like swimming freestyle (elbow above the palm and shoulder). I also tried starting from a T-pose and moving into the beginning of my movement from there, but the tracking quickly lost one of my arms and just left it poking into the body.

I read on another forum post that a T-shirt over a long sleeve shirt can help the arm tracking, so I tried that, but didn't have any luck. I accidentally bumped one of my cameras so now I have to start over with calibration.

Finally, on the subject of calibration, I'm having an especially hard time getting the ground plane to work. I set the ground plane after calibration, the scene looks good with the cameras at the right height and position. But then I move on to tracking and the ground plane superimposed on the video is a good 30 cm off the "real" ground.

Suggestions?
As I said, I'm feeling pretty surprised by the amount of manual setting and tweaking I'm having to do. I expected some of that, but not two full days' worth.

EDIT: I rewrote this post to be shorter/clearer, but in doing so took out one bit of praise: the calibration did a fantastic job of figuring out where my marker was going in 3D space. Didn't want to just sound like I was complaining. =)

You should not have to manually move the virtual cameras. If the calibration data is good, the software will automatically position the cameras with reasonable accuracy after calibration is complete.

When calibration is done, you need to set the scale of the environment by entering the actual height of one camera. For example, if Camera #1 is 1.8288 m up, you need enter this exact value for this camera. Assuming the calibration footage was shot correctly and successfully processed, the entire scene should now more or less reflect 'real world' scale. You might notice that the other cameras are not at exact heights but they should be pretty close.

You can't track successfully without good calibration data, so I would first make sure the calibration data is good before proceeding. Otherwise, you'd be wasting your time.

If you're interested, I've posted how I do my calibration video here:

http://www.youtube.com/user/LGDTestTube ... lG1_65s2_c

This pattern works every time for me.

For an example of an outdoor calibration session, I highly recommend viewing 1k0's Making of Danse Kabyle video:

http://vimeo.com/22036677

Hope this helps.

_________________
Greenlaw
Artist/Partner - Little Green Dog | My Demo Reels (2013,) (2015,) (2017,) and (2019)

Watch a one minute excerpt on Vimeo now!

Thanks Greenlaw, your comments are absolutely correct.

In addition to this, I can recommend the following:

1) Check the background ("Background" button on top) and first few seconds of your video. Actor should not be present in view of the cameras in the beginning of the video. This is a very common problem.
http://www.ipisoft.com/en/wiki/index.ph ... background
2) You should not move virtual cameras after calibration.
3) Please send us your video - this can help to track down the problem.
http://www.ipisoft.com/en/wiki/index.ph ... ch_support
If you cannot send the video, please consider sending screenshots. It can be hard to understand what is going on without seeing your environment and your actor.

Thank you both very much for your quick and detailed responses. I'll double check all the things you mentioned and try again.

My calibration from this morning finished with Camera 4 much closer to its real height, so I'll try tracking with this (hopefully more accurate) calibration data and see if I get better results.

Thanks.

EDIT:
Tracking is working much better now. I've got a couple hundred frames which look good other than the obvious jitter before post-processing. One thing that's still a problem is the ground plane. It's too high again by about 6 inches. The "ground height fine-tuning" slider only lets me adjust it about half as far as it needs to go. So I'm going without foot tracking for now.
Has anyone else had the ground plane too high problem? I'm certain my marker was no more than an inch from the ground in my calibration video. =(

FYI to others reading this who might be having similar problems, my capture area is lit by a very "yellow" overhead light. This seems to have reduced color contrast in the recorded video, so I had better luck changing into bluish colors to contrast with the beige and off-white walls and background.

Good calibration is a requirement. No capture will be done with out it. If you hurry or do not get good ground points, when you go to the renders for motion capture you will find the guy (DMC's rig) curling up into a ball then zooming off screen. Instant sign that you need to recalibrate.

Three things, I use a small level across the top of the PS3 cameras when setting them up.

Try to keep the distance of each camera uniform, then open DMC after calibration and look at each camera from a different camera view. Is the real camera and the software camera almost in the same position? If not try moving the camera on the next calibration. Not so much as height but position on the floor to where you think the software camera is.

More light the better, Get rid of the window or other lights that you have no control over. Sunlight can change from moment to moment. Try to keep it uniform so their is no dominant shadow.

Dale