This seems like it ought to be extremely simple to set up… I can think of a really complicated and hacky way of doing it, but I know there’s got to be a better way.
Basically, what I want is a translucent material which overlays everything inside of it.
So, you have a box with a translucent material for orange liquid, say. And from outside, everything is colored orange, and that works. But once the camera goes inside this box, that orange disappears; stuff OUTSIDE the box (through the planar surfaces) is orange still, but everything inside the box is normally-colored. I’d like to define the VOLUME has having a translucent hue, so that from inside everything appears orange.
This seems like such a rudimentary effect, but the only solution I’ve come up with so far has been to use a postprocess volume for the switch to the inside, and that seems like it can’t be the best solution…