I guess that this topic has been covered here but I couldn't find an answer on search so if you could point me in the right direction, it'd be great.
I have multiple shots of a room and I want to project animations and motion graphics made with cinema 4d onto the walls as if they were happening there. So I guess that I'll have to do some sort of tracking but I don't know if this tracking should be done in a 3d tracking program (boujou?) before I make the animations in C4D or in After effects? I don't know if I explain myself correctly but the effect should look as if you were playing a projector on the wall.
Also, how do I make it look as if the animations are painted underneath the wallpaper. Just a blending mode?
And if i wanted those 3d animations to come into the real world and 'interact' with reality, would it be the same workflow?
I have done something similar using Maya. Although I am relatively new to all of this, I'll try to answer your questions (others feel free to correct if necessary).
- As long as the "wall" in AE can use textures, there shouldn't be a need to track anything. In c4d, render your projection as a Tif sequence with an alpha channel. In AE, the wall should be a 3d object. Then import the tif sequence and make it a 3d object as well. Align the two and you should be good to go.
- You can change the opacity of the c4d animation OR the wall in order to have the wall color/texture show through. Playing with the opacity of both should yield the results you want.
- In order to accurately interact with "the real world", then the easiest thing to do would be to animate ALL objects in c4d. That way you have complete control over timing, etc. But if you want to interract with actual, live humans, then your timing will have to be carefully orchestrated. The only help I can give here is to have the "live" footage loaded in AE, and then adjust and render your animated footage to match. It will likely require many test renders, but is certainly do-able.
Ah, you're talking footage of walls that you want to composite your images on in AE?
If the camera moves, you might be able to get away with a 2d track using AE's built-in tracker or Mocha.
However, if it's not just a pan or tilt, but actual moving in 3d space, you will probably need to use SynthEyes, Boujou, or some other 3d tracker.
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If you just want the C4D renders to play on the walls as if projected, AE's corner pin tracker or Mocha will do the job if the wall has trackable features. I like the Soft Light mode for this sort of thing.
(Corner pin/mocha tracking works with 3D camera moves, but only if you're replacing a screen, or placing an image on a flat surface like a wall. It's when you need layers floating in 3D space with a 3D camera that you need a 3D matchmoving solution... or if the wall doesn't have trackable features.)
If you want the C4D 3D to interact with the talent, you should track the footage with Syntheyes or Boujou to create a 3D camera, then use the footage as a background in C4D and animate to the timing of the footage. You'll probably have to do some masking when real world objects come in front of CG objects.