I am rendering out a set of frames from 3DS Max Design that contain flame effects created in Phoenix FD. I was advised to render the flames separately to (for e.g.) TGA so that I could composite the actual image frames and the flame effect frames in After effects.
I rendered off both versions of frame 1500 of the animation (image and flames) and saved the image as TIFF and flames as TGA (making sure they are 32 bit and Pre-multiplied alpha is ticked). When I import the TGA into AE I get a message "item has an unlabeled alpha channel". When the frame is placed over its corresponding image the TGA has a black background and therefore covers the image.
There aren't that many settings for saving the TGA file but I have tried all permutations and none work. To clarify is this correct:
Targa image control dialog:
Bits per pixel 32. Compress, ticked. Alpha split, not ticked. Pre-multiplied alpha, ticked.
When I get the "item has an unlabeled alpha channel" message there are three options: Ignore, Straight - unmatted, Pre-multiplied - Matted with colour.
Q. Could someone please shed some light on these options and which I should be choosing (none appear to work!).
Q. Also, has anyone any ideas why the TGA has an "unlabeled" channel, and how I can rectify?
I don't have much compositing experience. This is something I have done once before and I had no issues.
Desperate for help, deadline looming!
Could you post one of the frames? It could even be cropped. Have you opened a frame in Photoshop?
I just got this solved. I was assuming that it was an alpha channel to give transparency so that the renders could be overlaid. However, the flames are ADDED (Blend mode) to the image in AE rather than laid over the top.