GI tab

This page provides information on the GI tab of V-Ray's Render Settings.

Overview

Global Illumination (or GI) is the illumination in a scene that effectively comes from reflected (or bounced) light as opposed to coming directly from a light source. This enables more naturalistic and accurate lighting solutions.

The indirect illumination controls in V-Ray are divided into two large sections: primary diffuse bounces and secondary diffuse bounces.

• A primary diffuse bounce occurs when a shaded point is directly visible by the camera, or through specular reflective or refractive surfaces.
• A secondary bounce occurs when a shaded point is used in GI calculations.

UI Path: ||Properties Editor|| > Render > GI tab

Global Illumination

On – Enables/disables indirect illumination.

Engine – Specifies the method to be used for the secondary diffuse bounces. This option determines the contents of the next rollout. Follow the link for each GI Engine, to see its options.

None – No secondary bounces will be computed. Use this option to produce skylit images without indirect color bleeding.
Brute force – Selects the brute force method (direct computation) for secondary diffuse bounces. See the Brute Force Engine section for more information.
Light cache – Selects the light cache method as the secondary GI engine. See the Light Cache Engine section for more information.

Use Light Cache for Interactive Rendering – When enabled, the Light Cache method is used for calculating global illumination in Interactive Rendering. Production rendering is done using the method specified in the Engine parameter.

Caustics

Caustics is an effect that is produced when light rays are reflected or refracted by materials, producing visible light patterns. See its options on the Caustics Rollout page.