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3D camera animation matching foreground

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Charles Hennegrave
3D camera animation matching foreground
on Mar 18, 2010 at 6:55:49 pm

Hello everybody,

I need serious help and I hope you’ll be able to help me… Here is the situation :
I’ve been asked to make a music video with a very short deadline (25/03/2010)! So far so good but where it gets complicated and real time consuming is that they’ve delivered me the footage shot in PAL HDV and, most of it was shot on a poor quality green screen with poor lighting making it very difficult to make a good keying job. That’s the first problem!
The second problem is that it was shot not using a stand resulting in a quite shaky footage with quite a lot of motion.
Here is what the band would like knowing that the budget is close to €0:
- Me to create a virtual rehearsal studio set (done with After Effects)
- Me to create a virtual office (done with After Effects)
- Render the whole video in Full HD (not difficult)
Here are my problems:
- The keying is not great so I opted for quite dark rehearsal and office 3D sets
- As the band what shot with a lot of motion, I end-up having to key-frame every frame to match the movement of the camera. This is the opposite of what I usually do, in this case I have to animate the background according to the foreground and it is taking ages to get it right.
My questions:
- How can I get a better keying?
- Is there any way I could track the foreground in order to match the movement of the camera and apply it to the sets in After Effects respecting perspectives…?
Here are the software I’m using :
- Adobe Master Collection CS4
- Boujou 4.1 (only started learning it though)
- Moka for AE
I could send you a sample (15 sec. or so) of the footage if you’d like in case my English is not good enough for you to understand my problems… I’m French, nobody’s perfect.
Thank you very much in advance for your answers

Best regards,

Charles


Charles Hennegrave
Vice-President of JC Dream none profit association
London


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Bruce Wainer
Re: 3D camera animation matching foreground
on Mar 18, 2010 at 7:46:12 pm

I think your first step should be to stabilize the motion, if possible. You say the band moves around a lot, does the camera move (other than shaking), or is it pretty much shot from the same direction and position? (relative to the green screen). If the camera moves, Boujou or another 3D tracker may be your only option (I don't know what is or isn't possible in 3D trackers). If the camera stay still, you should be able to use the 2D tracker in AE to stabilize the motion. Either way, You'd need some stationary equipment in the frame to track. If there is none, then ignore everything I said be cause it is irrelevant. Good luck.


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Charles Hennegrave
Re: 3D camera animation matching foreground
on Mar 18, 2010 at 7:52:02 pm

That's the problem, not only the shot is shaky but the camera also moves. Thanks for your answer. If you have other ideas, don't hesitate!

Best regards

Charles Hennegrave
Vice-President of JC Dream none profit association
London


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Michael Szalapski
Re: 3D camera animation matching foreground
on Mar 18, 2010 at 8:43:00 pm

Geez, I hate this kind of thing. People think just because they're standing in front of green that we can do anything. It absolutely must be planned out ahead of time. It absolutely must have good lighting. WE ARE NOT MAGICIANS!!! GAH!!!

Terrible source footage (in HDV, no less!), not planned out first, almost no budget and an impossible deadline? Somebody's getting screwed and I think it's you. (And not in the good way.)

Right, rant over; let's try to help you be a magician.

The camera moves...and is jittery. Actually, that will really help sell the fake set, IF you can get a good track. You will probably need to use SynthEyes, Boujou or another 3d tracker to get the correct camera data into After Effects. Although, considering how poorly they've obviously done on the planning end of things, it's likely that they didn't give you any good tracking markers either.

Useful info on better Keylight key here and here. Also check out this tutorial; no matter what kind of keyer you're using this can prove very helpful.

Also something to keep in mind when working with HDV footage is this sage advice from Dave LaRonde:
Dave's Stock Answer #1:

If the footage you imported into AE is any kind of the following -- footage in an HDV acquisition codec, MPEG1, MPEG2, mp4, m2t, H.261 or H.264 -- you need to convert it to a different codec.

These kinds of footage use temporal, or interframe compression. They have keyframes at regular intervals, containing complete frame information. However, the frames in between do NOT have complete information. Interframe codecs toss out duplicated information.

In order to maintain peak rendering efficiency, AE needs complete information for each and every frame. But because these kinds of footage contain only partial information, AE freaks out, resulting in a wide variety of problems.
And Adobe agrees.

I hope this helps.

- The Great Szalam
(The 'Great' stands for 'Not So Great, in fact, Extremely Humble')

No trees were harmed in the creation of this message, but several thousand electrons were mildly inconvenienced.


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Joey Foreman
Re: 3D camera animation matching foreground
on Mar 18, 2010 at 8:43:49 pm

Is there any gear like a light stand or a shoe or anything outside the frame of the screen?

Does anybody in the band keep one foot planted in position?

If not, you'll never be able to stabilize the shot. If you can't stabilize it, you cannot match a background plate.

You'll have to go for some sort of crazy random moving abstract background, assuming you can even pull a decent key.


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