Volumetrics

This extension actually consists of 3 types of volumetrics:

• "Constant density" - creates a cube shaped volumetric area in your scene which has a constant density. This is useful for very large atmospheric haze effects for example.

• "Noise3D" - this also functions as the constant density type except it also adds an adjustable 3D noise to create density variations in the volume.

• "Particle based" - this lets you use a particle simulation to define the volumetric density. You can either use particles directly in supported applications (such as Maya, 3ds Mac, Cinema4D, Softimage), or load an external particle file in several formats (.abc, .bin, .pxy, .prt, .rpc).

Constant density

This will actually be a separate cube shaped object in your scene, which can be manipulated like any other object (translated, rotated, scaled). The volumetrics will be visible only inside this cube shape. Please see your plugin documentation for specifics on how to add a Constant Density object to your scene. In Maxwell Studio, you can add it by right-clicking in the Object panel and choosing Create Extension Object>MaxwellVolumetric.

An example mimicking heavy atmospheric haze using the Constant Density cube encompassing the scene, and the resulting renders with/without the volumetrics. Note that a very low density of 0.003 was used since the Constant Density area was so large in this case (1km). The Maxwellsea extension was used to create the terrain.

Noise3D

As mentioned above, this type also uses a cubic shape to define the volume, but adds a 3D procedural noise to add some variation to the density. In the following examples, the density has been set very high to make it easier to see the changes to the noise parameters.

Seed

Define a starting seed for the randomization of the noise pattern

Detail

Create larger or smaller sized noise detail. In other applications this parameter is sometimes referred to as "frequency".

Detail parameter from left to right: 2, 4, 8

Octaves

The number of times that the initial noise pattern should be repeated. With each repetition (octave) the noise will be half the size of the previous octave. The effect will look similar to having an initially smaller Detail, but the difference is that the larger initial Detail will still be visible, and the Octave parameter will add smaller noise to the initial larger noise pattern.

Octaves from left to right: 1,2,3. Detail level was kept at 3 and Persistance was kept at 1 for all renders.

To better visualize how the Octave parameter affects the noise pattern, lets look at it through a 2D cross section:

Octaves 1-5. Notice how with each octave, the noise gets finer and finer while still retaining a part of the original large noise created in the first Octave