Overview

God rays is a volumetric effect, often used by 3D artists to achieve a more dramatic effect to a 3D scene. This effect is caused when direct pointed light (such as a sun) passes through dusty or foggy atmosphere.

Creating God Rays in 3ds Max

To create God Rays effect in V-Ray for 3ds Max, follow the steps below.

Video tutorial can be found here.
Example scene can be downloaded from here .

1. Create a camera, e.g. V-Ray Physical Cam.

2. Create a light, e.g. V-Ray Sun.

3. Add VRayEnvironmentFog effect from: Rendering menu > Environment > Atmosphere rollout > Add button > VrayEnvironmentFog

At this point Environment Fog should be visible in the rendered image. To achieve a more convincing effect, adjust Fog Color, Fog Distance, and Fog Height parameters accordingly.

Fog Distance and Fog Height parameters operate in Scene Units . For easier setup it is recommended to know the size/scale of the scene.

4. The fog color parameter determines the color of the fog.

5. The fog distance parameter controls the fog density. Larger values make it more transparent, whereas smaller values make it more dense.

6. The fog height parameter determines the height of the fog.

When multiple lights are present in the scene but you want only some of them to be responsible for the god rays effect, you can include or exclude light sources by disabling the Use all lights option in the VrayEnvironmentFog nodes rollout and clicking on the Add button.

For a more realistic effect, set the fog height to be higher than the position of the camera, and if the scene allows it, to cover any visible part of the scene.