Combining channels from different tops in a dynamic way over time

Beginners
1

Good day :slight_smile:
Say I have
a) A png image in a top, with alpha transparency
b) A ramp on another top

I want to combine the R,G,B channels of b) with the Alpha channel of a) , and get the output on a null

I use a composite node, with the “atop” setting. My question is that I want that combo to happen gradually over time. Meaning:

  • At the beginning of playback I would like the null to have only the channels of a). Over time, as time progresses, I would like to get the r,g,b channels of b) progressively take over the r,g,b of the null. How could I do that?

thank you :slight_smile:

2

I usually fade the image with an operator before it goes into the composite. This can be done a lot of ways, but the most obvious is probably the Opacity parameter on a levelTOP, which can be found on the “Post” parameter page.

1 Like
3

@Ivan thank you very much, will try that and report back :slight_smile: