Nuke Compositing Help

#1

I’m working on an indie feature and they use nuke, so this is pretty much my first time using Nuke (I’m an AE artist/Compositor on most projects), except to familiarize myself with the interface. I had a few questions though:
1: As you can see in the image, the Read 1 is being stretched so that it fits the size of the Read 3, but I want the overall Comp size to be from Read 1, how do I do that?
2: The original plate was shot with the background completely black and no tracking markers (because there was no VFX Supervisor on the project until the post stage) so how can I do a manual track so the image that is being used in the background is tracked correctly?

All help is greatly appreciated guys!

HERE IS THE LINK TO THE IMAGE: http://i183.photobucket.com/albums/x297/DaMaher/shot4_46.jpg

#2

Hey Demaher,

Welcome to the Nuke club :slight_smile:

  1. You have to resize the background plate with a “Reformat node” to match the forground plate. If you just want to get rid of the stretching, attach a “BlackOutside” node to the image with stretching and it should dissapear.
  2. I really need to see your shot to be able to help you with this one.

Hope this helps!

#3

See answer above.

Nuke uses the “B” input (as in “A over B” or in other words “FG over BG”) to determine the size of the merge node - your best bet is to reformat/crop the BG so it’s size is the same as the FG.

If you really want to reverse this you can use an “under” operation within the merge node which will effectively reverse the layering operation (“A under B” or “FG under BG”) - you’ll need to plug the BG into A and FG into B so it becomes “BG under FG”. Because the FG is plugged into B it’ll use the FG node to determine the size of the merge.

No2 is tricky. How much camera movement is in the shot? What type of movement - pan/tilt, dolly, handheld, steadicam? Any static features in the shot you can track?

#4

This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.