General Stereoscopic 3D and greenscreen

W

WhiteMonkey

Well-known member
Hi all. I'm interested in stereoscopic 3D and I've got two 7Ds to use. If I shoot against a greenscreen how do I set up the background and foreground in Post?

Do I use the 2.5D camera in AE to create the 3D environment with and set up a virtual 3D two camera rig and then composite the live action footage after rendering?

I'm trying to figure this all out in my head and some help from someone with experience would help.
 
I think a better explanation of a specific shot you're trying to accomplish would help. What you mentioned regarding AE doesn't sound like what you're going for, but then again, I'm not exactly sure what you're trying to do.
 
Handsome Pete,

What I'm trying to do is add background and effects and they need to be in the same 3D space as the live action footage. For instance, how would I add an explosion to the background?
 
While I haven't done it, your first idea sounds roughly correct.

Make a comp with your 3D environment to scale, and two cameras matched to the IOD and convergence of the 7Ds you shot with. Dupe that comp and switch the camera layers so the other eye renders, and then composite each behind their matching eye from the keyed 7D footage (as 2D layers). Then make a new master comp with the two individual eye comps channel-mixed for whatever kind of glasses you need (or side-by-side for youtube).

Having said that, I think you're in for a lot of trial and error getting the convergence to match just right and not cause all kinds of headaches and depth issues. And get a really clean key from the greenscreen footage (no small feat on its own with the 7D), since I'm sure keying artifacts don't look any better in 3D.
 
Thanks MaxThomas. I think you're right and it's going to be trial and error to get the convergence to match. My main issue is not to lose the depth in the live action footage. I thought I would lose that by turning the stereo layers into 3D layers and probably would. It never occured to me to use the live action footage as a 2D layer in AE.

As I do this, I'm sure the whole 3D thing will go away again and this will end up being another useless skill I have acquired. Funny thing, I'm an Andrew Kramer disciple, www.videocopilot.net, and he's all into stereoscopic 3D now. I've been trying to figure this out for a month.
 
Shoot your green screen with lots of tracking markers. Track the shot footage in a 3D camera tracking program, PF track, PF Hoe, Bijou, Sythneyes ect.
Export the camera data and track it gives you to a 3d program or as an After effects camera. Bring in your explosion footage and move it back in 3d space, Z depth, and comp it in.
In a but shell you have to recreate what you shot in 3d in After effects. And you'll have to roto out all the tracking markers. Painful but doable.
 
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