Overview

The VRayVolumeGrid Atmosphere settings rollout is available in the Environment and Effects window after a VRayVolumeGrid object is created. The Environment and Effects window can be accessed by choosing Rendering Menu > Environment, or by pressing the shortcut key 8.

To display the rollout, access the Environment tab in the window, and in the Atmosphere rollout click VRayVolumeGrid to select it. The VRayVolumeGrid Atmosphere settings rollout then appears at the bottom of the window.

UI Paths

||Environment and Effects Window|| > Environment tab > Atmosphere rollout > Effects > select VRayVolumeGrid

Parameters

Gamma Correction – Applies gamma correction to the volume effect. This option only has an effect if Mode in the Rendering rollout on the Modify panel is set to Volumetric, Volumetric Geometry, or Volumetric Heat Haze.

Note: This value should only be changed if needed for specific obsolete linear workflows. In newer versions of 3ds Max, this value should be left at the default value of 1.0 for correct results.

Use Probabilistic Shading – When enabled, the volume grid will select a few samples along each ray based on the smoke density, and evaluate the volume lighting at those points. When disabled, the volume grid will evaluate the lighting at each step of the ray marching algorithm. The probabilistic mode is particularly useful when using the Progressive sampler in V-Ray, as well as when using complex lighting on the volume. This option applies only when Mode in the Rendering rollout on the Modify panel is set to Volumetric, Volumetric Geometry, or Volumetric Heat Haze.

Samples – Specifies the number of probabilistic samples to use when Use Probabilistic Shading is enabled.

GI Samples – Specifies the number of probabilistic samples to use for GI rays when Use Probabilistic Shading is enabled. This should be kept as a relatively small number in order to speed up GI calculations.