Cryptomatte

This page provides information about the Cryptomatte render element in V-Ray for Rhino.

Overview

Cryptomatte is a method developed by Psyop for efficiently encoding accurate mattes. It typically uses three to five automatically generated render channels stored in a multichannel OpenEXR file which removes the hassle of creating dozens or hundreds of Multimattes.

The Cryptomatte render element works with both Progressive and Bucket Image Sampler.

Compared to the Multimatte Render Elements, Cryptomatte offers the following:

• Does not require a setup with object IDs, etc.
• Only requires a fixed number of additional render elements, typically four.

The Cryptomatte render element can be used for post-production using 3rd-party software plugins, such as the Cryptomatte plugin for Nuke or Fusion and Exr-IO for Adobe Photoshop.

UI Paths

||V-Ray Asset Editor|| > Render Elements (right-click) > Cryptomatte
||V-Ray Asset Editor|| > Create Asset (left-click) > Render Elements > Cryptomatte

Parameters

ID Type – Specifies how the ID mattes are created.

Object Name – Creates mattes based on object names. Note that object IDs are used in case no scene name is specified.
Material Name – Creates mattes based on the materials in the scene.
Object Name with Hierarchy – Creates mattes by object names with full scene hierarchy path.
Layer Names – Creates mattes based on the layer names the object belongs to.

Common Use

After producing a multichannel exr image with the Cryptomatte layer, we can use it in a compositing application, such as Nuke, to color correct the image. This example shows the before and after color correcting.