showing virtual cameras in other compositions

[Filip Vandueren]

Hi David,

there’s no need for expressions or 3D cameras, but it does require some careful planning.

First thing you need to do is create a comp “cropping setup” that visually represents the setup how it is going to look, this will probably not need to be as wide as 3840*720 because the two plasmas are much smaller than the projection screen, yes ?

Something like this:

Make sure the spacing and scaling of the 3 screens is as close to how it will end up in reality.
I started with a 2000 x 720 comp, and placed a solid of 1280*720 at the center.

I duplicated this solid twice and rotated, scaled and positioned them untill it looked OK. (it’s important that you start from a 1280*720 solid, even if the plasma’s are much smaller)

I placed a movie on top using “Preserve Transparancy” to preview how the cropping would look. (and some texts just for labeling this now)

I named the solids “crop 1-3”.
You should do your animation in another composition of this size, and visualize how the cropping will appear by replacing the movie-layer (4) with that precomp.

Once your animation is done, we are going to create a new Comp: “Uncrop”
This comp should be 3840*720, it is your final output.

Create three Solids of 1280*720 and place them perfectly side by side. (hold down command-shift so they snap to the edges of the comp). They will end up at positions:

[640,360] [1920,360] and [3200,360].
name them left to right: mask 1, mask 2, mask 3

now drag the Comp “Cropping setup” into this comp, and duplicate twice so we have three copies.

name the first copy “uncrop 1” and position it at the same pos as mask 1: [640,360]
Now, we will do the reverse transformation of what we did to the solids in step 1.

my solid “crop 1” had:
position: [180,360]
scale: [40,40]
rotation: -90°

first: anchor-point and position are the reverse of each other, so I’ll just enter [180,360] as the anchorpoint of “uncrop 1”
2nd, the reverse of a 40% scale = 10.000/40 = 250% scale
3rd the reverse of -90° rotation is of course +90°

Done. Place the “uncrop 1” layer underneath “mask 1” layer and enable TrackMatte: Alpha Matte “Mask 1”

For Uncrop 2 (which was unscaled, unrotated, and centered in my example) I end up with:
position [1920,360] (same as mask 2)
anchorpoint: [1000,360] (the position of layer “crop 2” in the “Cropping setup” comp)
scale= 100
rotation= 0°

Again, place underneath Mask 2 and apply track matte

Finally do the same for copy 3…

here’s my endresult:

I hope that was clear.

[David Denker]

Right, the two plasmas are much smaller.

Oh man, i could kiss your feets. Your understood exactly what I wanted.
The idea ist actually very easy, but i didn’t even start to think about that there might bei such an easy way i was just focused on cameras and expressions 😀

Thank you very very … very much for this detailed tutorial.

David

[Filip Vandueren]

You’re welcome.

I did think of a downside:

You may want to enable “collapse geometries” on the two Plasma uncropped layers:
in my example they were scaled up 250%, so that will mean some loss of quality.

You can regain some of that quality (especially if your footage is vector-stuff) but the only way to have the plasma cutouts razorsharp is to have the original animation at a much higher resolution.

I tend to not worry about that since spectators are going to stand pretty far away from the plasma’s so they won’t really notice a bit of pixilation/blurryness.

But just so you know…