Realistic Water with POV-Ray

A Hole in the Water - Whirlpool

This tutorial shows how to make a hole in a water plane by simple CSG. At last we have to put a texture with an according "normal" component on the plane to simulate the wirling of the water.
For making it easier to see what happens a quater of the plane is cut off.

Hole in the water:
Description of this scene for POV-Ray: .pov file or .txt file

We take a xz plane and a cylinder as deep as we want our hole to be. The upper end must be a little bit higher than the plane to avoid coincident surfaces in difference.

We subtract this cylinder from our plane.
We've got a hole with a sharp edge.

To get a round edge we have to take another cylinder of the radius of our first cylinder plus the edge radius which we want.

Once again we subtract it!

Now we add a torus with
the major radius = radius of our first cylinder
and the minor radius = our edge radius.

This is all we need for a hole with a rounded edge.

At last we have to add to our water texture
a normal like this:

   normal {spiral1  20  0.25
           sine_wave
           turbulence 0.1
           rotate<90,0,0>
           scale 0.5 }

That's it!

part I | part II | part III