Sub Surface



The SubSurface Environment entry is used by the DreamScape: SeaMaterial to determine the underwater color. This feature is especially useful for rendering a shallow water effect.


This is also used by the SeaMaterial and 3ds Max to calculate the effects on underwater scenery. When you first add the DreamScape SubSurface atmospheric, you are provided with 2 options for how to calculate the underwater volume - the Simple Model or a Physically Based Model. Both can be used to great effect.



Common Parameters

Sea Level - This parameter will specify the sea level. It is important to enter correct values as the SubSurface Atmospheric does not know where the actual sea level is.


Density - Controls how fast the visibility will drop by the depth and distance.


Density = 1.0

Density = 15.0



Simple Model

Max. Step Size - To calculate the color of the pixel, the SubSurface atmospheric has to perform numerous steps through the sea volume. By default, SubSurface will perform 10 steps, which is enough for most cases. However, in some scenes you might notice rendering artifacts, especially when looking straight down into the ocean. By lowering this parameter, SubSurface will perform more steps through the large volume and thus correct the final image (at a cost of some rendering speed).


Shadow Falloff - This spinner controls how quickly the subsurface volume casts into shadow. Higher values produce more realistic shadowing.


Note: If you have objects going into the water and have high Density settings, be aware that low settings can produce odd results here. Crystal clear water will have a low Shadow Falloff AND Density spinner


Color - The color of the undersea volume.



Physically Based Model

Automatic / User Defined - When you activate the Physically Based Model for sub-surface scattering of the water volume, you are presented with two options - Automatic and User Defined. Be aware that both offer the same controls, only presented in slightly different manners. Automatic uses standard physically based sub-surface scattering to produce its effects, while the User Defined method lets you start with an Automatic setting and tweak it for more stylized effects.


Turbidity - This spinner defines the amount of particulate matter suspended within the underwater volume. This spinner goes from 0.0 to 7.0, with 0.0 being completely clear water, and 7.0 being very dirty, murky water.


">" - If you want to see the coloration and Back Scatter values associated with the Turbidity spinner, click on the small arrow button ">" to the right of the spinner. This will pass the values to the User Defined section of the rollout.


Note: By adjusting this spinner's value, you are not only modifying the amount of particulate matter in the water, but you are also adjusting the coloration as well as shown below.


Turbidity = 0.0

Turbidity = 7.0


Scatter Color - When the User Defined option is active, this color swatch will become active and have an impact on the physical model. This is the color that the underwater volume with scatter light with. The result is that the water color set within the Sea Material will be affected by this sub-surface color.


Back Scatter - This spinner represents how much scattering is done within the underwater volume. Higher values produce more scattering and therefore more murkiness to the water. In the following example, a green color was chosen as the scatter color, and the values of this spinner were adjusted to show the results.


Back Scatter = 0.1

Back Scatter = 0.8