This page gives an overview of the Global Illumination render element and explains how it is used in compositing.
The Global Illumination Render Element is a color image that stores indirect lighting information coming from reflected diffuse light in a scene (without direct light and reflection contributions) when Global Illumination is enabled in Render Settings. This element may be used directly incompositing and adjusted for brightness and color to control the final image easily.
For even more control of indirect illumination without re-rendering the scene, the Global Illumination render element may be re-assembled by multiplying the Raw Global Illumination Render Element by the Diffuse Render Element:
||out Network|| > V-Ray Render Elements node > V-Ray > Render Channel > Color Channel > Type > GI
The parameters for this render element appear in the V-Ray RenderChannelColor render channels node.
Denoise – Enables the render element's denoising, provided the Denoiser render element is present.
Consider for Anti-Aliasing – When enabled, anti-aliasing will be used where possible.
Color Mapping – When enabled, the Color Mapping options in the render settings will be applied to the current render channel.
Derive Raw Channels – Generates data in the raw channels by combining the respective color and the filter color channels.
VFB Color Corrections – Applies the post render color adjustments made from the VFB.
The Global Illumination Render Element is useful for changing the appearance of Indirect lighting after rendering, using a compositing or image editing software. Below are a couple of examples of its use.
Tinted and Brightened GI