Blend a slab / videoplane and a qt movie?


    Mar 13 2013 | 8:12 pm
    Hi - I have a slab that is combining the output of syphon with a qt movie. I then want to alpha blend the result of this with another qt movie that will lay over the top and show the slab (syphon + qt) beneath using the alpha channel of the movie. I have the patch that renders the slab, and renders the qt movie, I just can't seem to find out how to combine the two.

    • Mar 13 2013 | 8:43 pm
      you just have to chromakey the results of your first chromakey with another:
    • Mar 13 2013 | 9:01 pm
      Is there a way to do this with an alphablend and not a second chromakey? Doing two chromakey operations doesn't seem to behave the way I want. All I want to do is have my video with alpha play over the top of my blended slab video.
    • Mar 13 2013 | 10:21 pm
      Why not use another slab with the co.alphablend.jxs shader?
      There's also a jit.gl.pix solution for alphablend unside the jitter-examples folder
    • Mar 13 2013 | 10:37 pm
      Oh, I got it. What you want to do is put your video with the alpha on a videoplane that renders on top of you background video, using the @layer attribute, and setting blend_enable to 1 on your videoplanes. See attached.
      M