I need to export some comps with matte passes to hand to another artist. We can't add an extra output in connect fx like we can in batch. I had to render each pass twice for front and matte and then export separately.
is there any better way of exporting front and matte from a connect fx in one render pass?
I think this is what you are looking for. Tip courtesy of BKM...
From his forum post...
5. Once you exit the Modular Keyer your MK node has a result and matte outputs. Pipe those in the CFX result and you will create a CFXa clip. Marrying the front and alpha.
6. Exit CFX.
7. Right click on Clip and COMMITT>COMMITT CFX -- this will render and create a Matte container clip, however, it will wipe out your raw CFX effect so I suggest you make a copy of the seqence before doing the commit process.
8. Once rendered you can close the seqence and export the clip as a Prores 4444. Since it is a Matte container the alpha will be embeded.
if you want to check you key along the way you can do that by pipeingina background clip in to the Modular Keyer node or by placing a clip below the CFX clip on the timeline. You may need to add an AXIS effect to the CFXa on the timeline to activate the alpha and Key.
From memory I think that will get you there. Let me know if you have any issues along the way.