Creating God Rays Effect

"God rays" is a volumetric effect, often used by 3D artists to add a more dramatic effect to a 3D scene. The effect is achieved when a directional light (such as V-Ray Sun) passes through a dusty or foggy atmosphere.

In this tutorial we explore the steps on how to get the effect.

Firstly, make sure you have a directional light like the V-Ray Sun in the scene. Other types of lights also work, for example a V-Ray Rect Light when the Directionality parameter is increased.

Then, create a VRay Environment Fog.

To do so, navigate to Render Settings > Overrides > Volumetrics and enable the Use environment volume option. As an Environment volume map select the VRayEnvironmentFog volumetric.

The fog now renders in the scene, but the default settings do not suit our scene's measurements well.

Let's explore the Fog Distance and Fog Height options. Both of these parameters work in scene units. It is recommended to know the size/scale of your scene in order to input the right values.

The Fog Distance parameter controls the distance of the fog from the camera, essentially controlling the fog density. For this particular scene, a value of 10 makes the fog extremely thick, so we increase the Fog Distance to something like 800.

The Fog Height determines a point along the Y-axis from which the fog starts and goes downwards. A value of 100 is lower than the mushroom's height, so let's also increase it to 800.

Now it seems to cover all of the greenery in the scene.

The fog color parameter determines the color of the fog - see how changing it affects the overall mood.

To make the scene look faerie, we can play around with the Fog Color. For this scene, we settle with dark blue.