Really struggling with figuring this one out! I have some transparent/translucent materials I'd like to render on different passes. I am using some mask holdouts to get around misbehaving booleans for a faux "fluid sim" that involves filling a complex shape (deserves another post..) From the display inside Blender, they appear fine. However, when saving as a PNG, EXR, or multilayer EXR, the alpha channel is speckled.
Funnily enough, this is the same alpha I get when checking "convert premultiplied" in the compositor when I try using the alpha over node. Same speckled appearance when I have the alpha convert set to premultiplied. Note that I dont want to use the blender compositor for my final file export.
Blend - https://we.tl/t-ijQ126oytW It just seems that blender's viewer is handling the alpha channel differently then when you try to save a file out of it. Thanks!