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Motion Tracking in C4D: Solved Camera Has Only Partial Keyframes
Hi all,
I’m tracking a shot in C4D. The motion tracking is going well- the motion track object has tracking points that it successfully follows through the shot.
However, when it comes time to do the Full 3D Solve, and create a Solved Camera, the camera it creates only has keyframes for part of the shot.
The shot is 1024 frames, right now the solved camera has keyframes for frame 777-1024. If I limit the footage, to try to break it into chunks, it still only gives me a camera with a random section of keyframes- sometimes only 5 keyframes, sometimes 155. I’ve tried changing the resampling rate, but that does nothing. I’ve tried doing a manual track, and the solved camera it creates also has a random chunk of keyframes (734-831)
So the issue doesn’t seem to be with the motion track object, because it’s tracking points well, but how it applies that data to the camera it creates, which is incomplete. I’ve had this issue with a couple shots now, so it doesn’t seem to be something specific to this shot. If any one has any advice, it would be greatly appreciated! I don’t have access to Syntheyes or 3D Equalizer, so they’re not really options for me.
Specs: I’m working in C4D R20. The footage was shot on a greenscreen soundstage on an Ursa Mini Pro with Zeiss lenses at 4k, ProRes 422, 30 FPS
replied 10 months ago 4 Members · 5 Replies
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5 Replies
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See that button on the 2d tracking tab that reads: “Create Auto Tracks”.
Don’t press it! You can but you’ll have to create them throughout the clip.
Instead just go straight to the “< Auto Track >” button below it. -
Thanks for replying! But the issue doesn’t seem to be with the track itself, it’s with getting the track onto the camera. I’m also doing a 3d track of the camera, not a 2d track (I’m actually confused about how the 2d track interacts with the 3d track, there doesn’t seem to be much use for it). Or am I missing something?
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You must do a 2D track of the footage first as that data is needed to solve a 3d camera.
The 3D solve will stop when there are no useful tracking points left to work with.The 3D solve should work but it does need 2D tracking data first. The 3D solve works by measuring the change of individual 2d tracking points frame by frame to determine surface information (parallax and spread) and then is able to generate camera vectors by averaging and negating the 2d track results. If there are not enough 2d tracking points per frame, the 3D solve will fail when it drops below a set threshold and assume the job is done.
Depending on the footage you are solving for it’s usually best to flood a bunch of tracking points from the start, auto track, then scrub through and delete the points you don’t want to evaluate in the 3d solve.
If you are talking about object tracking. That’s a different setup and you will need to correctly solve the camera motion track first.
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The best piece of advice I’ve read for ages! Thank you!
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Hi Emil,
Happy you found what you were looking for in the forum and thank you Emil for pointing out the importance of post, especially since the questioner did not comment on Sam’s answer. It was indeed a very useful post with accurately describes the solution to the camera solve stopping, and also provides a clear idea of the mechanism of tracking as a whole, Thank you Sam and Emil!
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