handmade.network » Forums » Questions on Premultiplied alpha
boagz57
Jason
100 posts
#20824 Questions on Premultiplied alpha
3 months, 3 weeks ago Edited by Jason on March 29, 2019, 6:46 p.m. Reason: Initial post

I just finished watching the pre-multiplied alpha video and I'm still abit confused on it's applications. Does pre-multiplied alpha only apply to situations where you are using pre-composites? Or does it also give you advantages (besides performance) when just calculating everything and drawing to the screen every frame? I only ask because I'm currently in the latter situation (no pre-composites/pre rendered textures) and so far is seems like just linearly alpha blending everything gives me what I need. Though I've heard that pre-multiplied alpha can give you more accurate color information and better texture filtering effects in general (without pre-compositing).

I've been trying to experiment with pre-multiplied alpha with my current setup and I keep getting wrong outputs so just wanted to make sure this wasn't because pre-composites are a pre-requisite to using alpha blending (if not then my math is just wrong).