Blend a slab / videoplane and a qt movie?

Mar 13, 2013 at 8:12pm

Blend a slab / videoplane and a qt movie?

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.

#67066
Mar 13, 2013 at 8:43pm

you just have to chromakey the results of your first chromakey with another:

– Pasted Max Patch, click to expand. –
#241369
Mar 13, 2013 at 9:01pm

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.

#241370
Mar 13, 2013 at 10:21pm

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

#241371
Mar 13, 2013 at 10:37pm

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

– Pasted Max Patch, click to expand. –
#241372

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