Maybe this is an obvious question: I've found that using a layered shader that has a mask that isn't pure black or white increases render time. Would it be a fair assumption that each material on a layered shader increases the render time because of more calls to calculate the final surface are required?
I've seen render times decrease when I use the mask on all of the individual component maps the go into a single CoronaMtl. I know this probably won't be a 100% perfect match to a layered shader, but I'm getting results that are pretty damn close. And if that means that I have to deal with a bit more of a messy shader network that produces a result that is a 95% visual match for an average saving of about 30% render time (sometimes much more!), then I'm happy with that.
