Merging multiple transparent textures/images ?

Shrike

Hey, so I have render out sprites for our game and the problem is that I have the shadows separated, and the renderer cant give them out together.

Its basically this; only that I have animations that go up to 100 frames.
(I have them in transparent PNG in the same image size but other formats are possible.)


The green is only to show transparency, its not in the images
Now im looking for some sort of way to combine them easily, as doing them frame by frame in photoshop is near impossible. I imagine it can be done in aftereffects somehow, but I couldn't really find out a way so far.

Maybe some sort of tool exists that combines two images ? As both are non overlapping and the same size, that should work.

Any ideas or software I don't know about?

EDIT: FOR ANYONE READING THIS THREAD - GAME MAKER STUDIO 1.4 Has a feature in the image editor called overlay which allows this and exports as a sprite sheet although not in individual sprites 

Scruples

Load into After Effects, each image sequence as a separate layer and render out.
I think the alpha should be set to pre-multipled in the properties of each image sequence but it's literally been like 10 years, so I could be wrong. (if it looks wrong ie. you get some fringing then it's wrong).

Shrike

Alright thanks, I will give it a try with after effects then again

cryrid

Softimage has a built in compositing tool for combining various render passes together, I imagine other packages would too (blender seems like the kind of program that would). Otherwise I imagine flash would handle it easily enough as well zero but if you have access to AE and are comfortable with it then there's probably no solid reason to switch.