This page provides information about the Refraction Render Element in V-Ray for Cinema 4D.
Overview
The Refraction Render Element stores refraction information calculated from materials – such as glass or water – that refract objects behind them in the camera's view. This means the brightness, coloration, etc., of the refractions can be adjusted without the need to re-render.
Any material in a scene with a value set for its Refraction parameter generates refraction information that can be seen in this render channel. A surface with no refraction values set in its material(s) contains no information in the render element and, therefore, renders black.
The Refraction Render Element is a key component in the main Beauty Element and can easily be used to control the refractions in the Beauty composite.
The Refraction Render Element itself is already a composite of the V-Ray Raw Refraction Render Element multiplied by the V-Ray Refraction Filter Render Element. When finer control over refractions is needed in the composite, add these additional two channels to the output along with the V-Ray Refraction Render Element.
This render element can be used to enhance the refractions of a scene after the render is complete. See the example.
UI Path: ||V-Ray|| > Render Elements > Refraction
(How to add a render element to a scene)

Properties
Enable Deep Output – Specifies whether to include this render element in deep images.
Color Mapping – Applies the color mapping options specified in the Color Mapping rollout of the V-Ray tab in the Render Settings window to this render element. This option is enabled by default.
Consider for Anti-Aliasing – When enabled, anti-aliasing is used where possible.
Filtering – Applies an image filter to this channel.
Vfb Color Corrections – Applies the post-render color adjustments made from the VFB.
Denoise – Enables the render element's denoising, provided the Denoiser render element is present.
Example: Enhance Refractions
In this example, the refractions of the windows in the scene are enhanced using the Refractions render element. The objects are isolated using Cyptomatte masks, and their refractions are enhanced and tinted blue.
