Ok, here’s the situation:
I have a big reflecting plane, which is semi-transparent (let’s say it’s water). There’s another object, partially submerged. So part of it is above the water, and part of it below it.
Now I want to create the reflection of that object on the water. But, here it gets tricky!
Using the standard plane reflection, by placing an empty below the plane and using that as the source of the envmap, won’t work, because this will also reflect the part of the object that’s below the water.
Is there a way to solve this, without cutting my partially submerged object in half (which would be very tricky to begin with, but impossible once I started animating the whole)?