I’m new to Continuum (2020.5) and my method thus far has been to create a Solid Color layer and add the Particle Illusion Effect, however I want the alpha of the layer to match the shape of the particles.
By default I get a solid alpha and have been working around it by adding a “Shift Channels” Effect and setting the Alpha to match the luminance - this seems to affect the RGB values (perhaps a premult issue).
By default Particle Illusion composites directly over the source media (in your case a solid). However back in the host you can use the Composite Style menu (in the Composite) group to change to Alpha + Apply Mode which gives you the raw particles with intact alpha channel and the option to choose between a variety of different apply modes if desired.
Brilliant! Thank you Jason. I normally use Nuke as a compositing package and I couldn’t figure out if it was a setting or something I was misunderstanding about AE workflow. Much appreciated.