What about Synfig provides a new blend method? It would be similar to “Alpha” blend option, but with a twist. Where shapes overlaps, region is transparent; where they don’t, they are drawn.
Example: One ‘yellow’ circle overlaps a red rectangle.
Composite blending:
Proposal:
Few questions:
What should it be called? The blending works similar to “Exclusive-OR” (aka. “X-OR”, “XOR”), a mathematical/boolean logic operation. But maybe it’s too technical?
How amount should affect it?
Should it exist?
Motivation:
To provide a feature SVG format does (multiple subpaths in a path element):
(Please note that it won’t change/improve SVG importing)
How about naming it Alpha Inverse? I’m constantly forgetting exactly what gets hidden with Alpha compositing. With Alpha Inverse, it’s one or the other.
Following the inverse logic for opacity, if the bottom layer, outside area fades in for Alpha compositing as the amount decreases, then the top layer, intersection area should fade in for the same circumstance with XOR compositing. The bottom layer, intersection area would always be hidden which is inverse to top layer, outside area for Alpha.
@GregorysonofCarl@Kai Sorry, I forgot amount was renamed to opacity in GUI.
So, opacity/amount1 must mean full transparency in intersection area.
What should mean opacity 0.0?
What should mean opacity 0.5?
@GregorysonofCarl proposes opacity for top layer (yellowish circle) does not affect bottom layer (red rectangle). The outside area of top layer should behave as in Composite mode. I understand @Kai has the same opinion.
But what about the intersection area when opacity is 0.0? Should it fully show the yellowish circle?!
So it’s basically “Alpha Over” except it keeps the overlapping shape intact? Then maybe “Alpha Composite”?
Also, I think that “amount” should affect the outside area too. It’s what user expects when changing “amount/opacity” for it to affect the whole layer, not just part of it.
In my opinion, i don’t think the person who created the issue was looking for halftone like feature. He basically wanted to create those grainy shaded effect. Like in this pic he posted…