Rendering comped vfx shots with matte in alpha channel

[ScottJG27]

I need to deliver ProRes 4444 Quicktimes of final vfx shots with a matte in the alpha channel so that foreground and background elements can later be color-corrected independently of each other. The post facility requested that the alpha be set to ‘none’ instead of ‘straight’.

In the past I’ve delivered shots as DPX or EXR image sequences, and mattes as separate image sequences, this is my first time trying to combine them into one ProRes Quicktime delivery and can’t figure it out!

Any help anyone can offer would be very appreciated, thank you!

[Rick Gerard]

You have to render an RGB copy and another Alpha Only copy. They will need two copies of the shot. I'm not sure why they want a separate alpha because every editing and color correction tool I know of can pull a matte from any other layer, but if that's what they want, just selecting Alpha Only will do the trick. It will just increase your render time.

[ScottJG27]

Figured it out, I had to render ProRes 4444 XQ and not ProRes 4444. Now when I import the XQ render and Ignore Alpha, I can see the bg plate when viewing "Straight Unmatted" in the channel viewer, whereas with regular ProRes 4444 it wasn't showing up.

It's very handy so now I only have to deliver one matted shot instead of two shots, an RGB and a matte. Saves delivery file size heaviness, and time having to line-up a separate matte layer in color-correction.