Hide water surface in room

Hi all,

I have an empty room with a FPS-Camera inside. The room has windows. This room may fall into water and can sink. The player inside the room should stay dry. So what do i have to do, that the water surface is not shown for the FPS-Camera inside, but visible at the windows?

I found solutions for hiding the surface from a top view on a boat (depht mask), but not for a moving surface that can be over, under and directly on the camera. I tried to hide the complete water object for the FPS-camera and used render texture with other cameras for the window. But as render texture is only a 2d image, this solution doesn’t work for me.

Do you have any ideas? Thank you so much!

Maybe you could make a huge plane in blender, cut the size of your room as a hole into it and apply your water shader to it.

You can animate the window with no water at all just an image that changes as if the water was reaching the top, you could make it change with time or something