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facebookarchive / Surround360

Surround360 is Facebook's open source hardware and software for capturing stereoscopic 3D 360 video for VR. The repo contains hardware designs, as well as software for camera control and rendering.
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number of cameras and overlap #74

Closed cvaldesmol closed 8 years ago

cvaldesmol commented 8 years ago

I have been playing with i = r * sin( FOV/2 - 360 / n) My cameras have a vfov of 79 after distortion correction. I see I can work with 6 cameras (maybe 5 if I increase the r) but what about overlap? how do you take that into account? what is recommended? with 6 cameras I get 79*6 = 474 degree I heard that you need at least 720 degree if you want 3d, is that true?

fbriggs commented 8 years ago

With our software, you need to have i > 3.2cm. There is nothing about our software that relates to 720 degrees. 6 cameras is probably not enough, unless you have a very large r (which won't work well because it makes the optical flow problems too hard). For example our current rig has n = 14, FOV = 77, and r = 21cm.

cvaldesmol commented 8 years ago

I kept thinking and I guess that to get 3d you need full overlap of each camera. Maybe something like camera 1 overlaps 50% of camera 2, and camera 2 overlaps 50% of camera 3. So camera 2 has full overlap using camera 1 and camera 2. So for my 79 degree camera I need 10 cameras regardless of r. Am I right? If that is the case, is 10 good enough to get high quality 3d? or more overlap is required ?

fbriggs commented 8 years ago

It has nothing to do with how many overlaps or how much overlap you have. Its all about that formula i = r * sin(FOV/2 - 360/n).

10 cameras might be enough, but I suggest at least 12.