Submerge

As light moves through murky water it is scattered by a myriad of tiny particles, causing the water to slightly glow. Because the light loses intensity as it is scattered, deeper water glows less than shallow water.

Submerge simulates this scattering effect, giving a realistic coloration to underwater scenes.


Procedure

When the camera is below the water -

Choose Atmosphere->Depth Fading.

Select Submerge as the atmosphere shader.

Edit Submerge's parameters.

When the camera is above the water -

In the water surface's material dialogue, select Submerge as the volume shader.

Edit Submerge's parameters.


Parameters

Surface Height sets the position of the top of the water. It is measured in SoftImage units from the world center.

Vertical Gradation controls how quickly the water becomes dark. Lower values will cause the water to be nearly uniform in color, while higher values will cause an abrupt change in water color, from the lighter areas towards the surface to the darker regions below.

Density controls how murky the water is, i.e. how quickly objects disappear as they become more distant. (Density is identical to the Density parameter of the Mist shader.)

NOTE: If banding occurs when using Submerge, simply turn on "Dithering" in the Render dialogue box to correct it.