August 01, 2009
Masking & Smart Filters
When you’re using Smart (re-editable) Filters in Photoshop, you can apply a single mask to all the filters on an object. Why, then, doesn’t the app let you mask each one independently? This question came to mind when photographer Ellen Anon said,
But my main request is that each Smart Filter needs its own mask. PLEASE!!!!
I know. There’s no question about the desirability of this support. The details are tricky, however.
The fundamental problem here is how to make filters live-update as you alter their source data. If you’ve read my post on The Secret Life of Smart Filters, you know that we purposefully chose to impose some indirection, making it harder to feel like you should be seeing filters updating in real time as you paint.
Let’s say you’ve created a Smart Object, and you’ve applied Filter A & then Filter B. The source data that B will process depends on the results of A (including A’s mask, if one existed). If each filter had its own mask, then painting on A’s mask would demand one of two things:
- B either has to keep running/updating as you paint (read: slow, at least in a lot of cases) or
- B must be shut off while you’re painting, then later re-enabled (when?).
The more filters you stack, the more demanding they are, and bigger your brush and/or file, the more processing wallop would be required to keep things interactive. And even if it were all infinitely fast, there’s the big challenge of how to deal with filters that transform/offset pixels (see aforementioned post).
These aren’t impossible problems, but they aren’t easy to solve, either. We don’t want to set you up for a crappy experience.