I have a few render layers mixed together to form my final image, as is rather customary. I'm using a mist pass and a couple of math and mix nodes to get a nice gradient to white the farther away an object is, also rather customary.
The problem is I'm having a little trouble tweaking the "mist" settings in the World panel to be quite right. I'd like to be able to change them and see the result...without re-rendering my entire scene.
Is this possible? Is it possible to replace only one single pass (such as "mist") for a render (across multiple layers) rather than re-rendering everything?