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vlad74
04-29-2011, 10:14 AM
Hi guys
I am working on a project and I have to incorporate some CG element into live footage. The camera is static all the time. What is the best way to match softimage camera with real one - what kind of info I would need. I guess the distance between the floor and the camera, the distance between the camera and the objects that need to be filmed, the lens of the camera.

Your input will be appreciated.

Thanks

oktawu
04-30-2011, 06:56 AM
since the camera is static, you could even approximate everything by eye. simple survey data might help, but if there is no movement, you could get away with it manually. in case of animation, just run the sequence through a solid tracker (like syntheyes), and about 80% of the time, you will get great results, with the occasional manual fiddle. (depends alot on the quality the sequence itself, and the amount of motion)

bravmm
04-30-2011, 09:09 AM
During the shoot, record all available camera info, e.g. camera height, lenses used, distance to lens, camera angle etc. Also measurements from the set would help a lot later on getting a proper match.
If you have all that info, it's the first step to quickly match the scene.

If all goes pear-shaped and there's just no time (happens a lot), just scribble notes as fast as you can during the shoot, and eyeball it when back.
If you have access to SynthEyes or PFTrack you can figure out the camera/lens, and even export the result to your 3D app.

rob

vlad74
04-30-2011, 09:34 AM
Thank you guys. That info was really helpful. The camera is static all the time.
Vlad

bravmm
04-30-2011, 09:57 AM
just remembered about this one, an oldie but still useful:
http://www.computerarts.co.uk/tutorials/premium_content/3d__and__animation/supervising_a_vfx_shoot
There's a pdf link at the bottom of the page.

rob

vlad74
05-01-2011, 12:04 PM
Thanks for your help Rob. That is really useful.

bravmm
05-01-2011, 12:52 PM
You're welcome :-)

Good luck on the shoot and the project!!

rob

vlad74
05-01-2011, 10:05 PM
Thanks man :)

calmasacow
05-10-2011, 08:00 PM
yeah Unfortunately Softimage's camera lacks a lot of the standard conventions that real world cameras. I guess the key thing is calculating the FOV since that is pretty much the only setting in the SI camera.

this site has a good FOV calulator: http://imaginatorium.org/stuff/angle.htm

Using this all you need to know is the resolution of the frame and then the focal length used on the camera at the time of the shoot. Then you can get the FOV from the calculator. once you have that you should be able to get it pretty close.

But let me say this. IT IS NOT GOING TO MATCH UP EXACTLY! once you get it close you are most likley going to need to remove the lens distortion from the image. This can easily be done in any compositor like AE, Nuke, or fusion or even composite.

Then load them back in and everything should be VERY close if not dead on.

Hope this helped.

bravmm
05-11-2011, 06:54 AM
There's a nice little plugin that will help a bit with setting up the camera, it's called Paparazzo. You can find it here:
http://www.sajjadamjad.com/plugins.html

rob

vlad74
05-12-2011, 03:55 PM
Thanks very much guys. Really helpful stuff.

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