Blackmagic Forum

Hey!
I have footage of a falling DIN A4 paper. Of course it is rotating around.
I would like to track it, to place an image on it.
My idea was to use the planar tracker. That works fine as long as the paper is not rotating.
When it rotates, the planar tracker aborts. What is okay!
I would like to continue the motion by keyframing the left frames manually. And then use that completed tracking for creating the planar transformation node.
But how?
Or how would you track a falling paper to place some graphics on?

Any chance we can see the shot? It all depends on a per case basis. The planar tracker is a bit of a black box, so adding keyframes manually - from within the planar tracker - isn't going to happen.
Depending on the shot, you might want to use the planar transform until it runs out and then use for example the grid warp to match move the remaining frames.

Yes of course!
I have recorded a quick screencast:
https://www.dropbox.com/s/f8j1l7jziezc7 ... r.mp4?dl=0

I posted this on the video, but I'll post it here as well:

At 1:06 when the paper starts dropping, you will most likely need to take over with a different method of matchmoving. I think you will have the best result with the gridwarp tool. since - as I can tell from your polyline attempt - it's a relatively easy object to roto. Just take the last frame of the planar transform tool that works and use that as the input of the grid warper with x/y segments set to 2. This will give you two additional 'warp points' down the middle of the paper that should cover the bending of the paper.

If you really would like to 'automate' this process you could use the regular tracker - this will interpolate between missing frames, so you could manually correct for it using the wrong corner when the paper flips over (as you mention at 1:18) , but since it's a relatively short shot, it's probably quicker to hand matchmove it to begin with, instead of 'automating' it and adjusting it afterwards anyway.

So if you use the gridwarp the way you used the polygon tool, you will get fine results.

If you're really happy with the polyline animation you could even link the points of the gridwarp to the points of the polyline, but again, this is probably more work than it's worth.

Amazing! Thank you for that detailed answer.
I will have a chance to try this in the next days.

Something i also did now: I have used Blender 3D and made a real 3d-paper that follows the original footage as close as possible (manual animated).
I think this way i am most flexible in creating VFX for this shot.

Using Fusion to composite it.

The next thing would be: Is it possible to remove the paper from the footage?

Somehow I'm not surprised you turned to Blender

Of course the question is: if the 3d paper is matched to the original, is there still a need to remove the paper or can you just layer on top of it?

Of course the camera is static in this shot and the movement of the actor is limited, so you could probably clone away the paper relatively easily. Of course that will be quite labor intensive as well.

I can't decide for you, but personally in this case I'd go the 2D route, since it's a relatively short shot.

Or you can render out whatever you need to be on the paper in 3D and put that on top of the original footage. There are so many possibilities.