Matting Out Background / Green Screen Assistance

Support Compositing and Post Processing
1

I’m using the video sequence editor and trying to achieve the general effect shown in the attached sample graphic.

  1. In the 3D View, I have a simple mesh of an HDTV (gotten for free as a .SVG from OpenClipArt.org).
  2. In a separate Scene in the Video Sequence Editor, I have a Star Wars video (not the one shown below, but that conveys the idea.

The goal is, obviously, to have the HDTV overlay onto the video, but to matte out the entire background from the HDTV layer. However, I’ve been fiddling with it and haven’t been able to achieve it yet. The tutorials that I saw all indicated that using Nodes was the best way to matte out a background, but I was hoping to avoid that since I don’t know how to do that yet. So any help is appreciated.

SW-Sample.png710×344 123 KB

Most people would probably have done this to start with, but I got around it like this:

  1. Used a .PNG instead of the .SVG graphic.
  2. Inserted the .PNG into the Video Sequencer Editor timeline
  3. The imported .PNG was distorted (automatically stretched to the corners of the screen). So, I added a transform (Add > Effect Strip > Transform). In that transform, I made sure to adjust the Alpha, and I also adjusted the image’s scale so that I squished it back to normal dimensions.
  4. However, now I had TWO TV images - the first imported one and then the second one from the Transform. So, I went to the initial imported .PNG and set its Opacity to 0.00 so that it was invisible.

Somewhere in there, I also had to add a Transform for the video, too, so that it could be scaled to fit inside the screen, and I had problems with the alpha channels and stuff, but overall it seems to be fixed now.

2

Check for a Picture in Picture or PIP effect blog entry in my sig.

3

I went to your blog and, I think, found the PiP page that you were mentioning: http://blendervse.wordpress.com/2010/10/19/vse-picture-in-picture-pip-effect/

I left this comment, which touches on an issue that others might have if they’re skimming through these message boards in the future, so I’ll post it here, too:

Thanks for the tips.

To Paul K and others who were having problems with the duplicate video/picture that results when you add a Transform to the original, my solution was to go to the original video/picture and lower its opacity to 0.00.

(I’m not sure that this was the problem that people were talking about, though.)