Cryptomattes - originally devised by Jonah Friedman and Andy Jones from psyop - allow you to store automatically generated mattes for all items or surfaces in a single OpenEXR image.
The levels determine how many different mattes may be stored per single pixel. 6 is usually a sufficient number.
You can also decide if the manifest - the file containing the names of the mattes - is stored embedded in the EXR image or as a separate file. exrTrader also allows you to select any of the OpenEXR compression types that are compatible with Cryptomatte.
This tab contains all Cryptomatte related functionality and is available with an exrTrader Pro license only.
Unfortunately, not all features of LightWave 3D can be used to create Cryptomattes. Currently there are two main limitations to the implementation 1):
While Cryptomattes will be generated with settings other than these, they may not match perfectly.
This defines the base file for the Cryptomatte export. This is a separate file from the main, layered, export. It supports the same varaibles as the Layered File control.
A selection of compression modes to use for the Cryptomatte file. This selection has been limited to lossless compression modes that will not destroy the Cryptomatte data.
exrTrader Pro can create three types of Cryptomattes:
The settings following the type are used for the currently selected Cryptomatte type only.
Removes any trailing numbers from an item name prior to using it to encode the Cryptomatte. This allows for items that use an object sequence to have an identical name throughout a scene.
This removes the (##) after a cloned item before encoding the Cryptomatte. This way, all clones of an item will use the same name as the original item and can be selected as one item in the compositing application
This defines how the current Cryptomatte Type will be saved:
This settings defines how many different mattes the Cryptomatte will be able to store per pixel.
The default of 6 is usually more than enough for most cases, you might want to increase this if you have many different overlapping mattes.
The name of the current layer. This will be used later in the compositing application to select the layer to work with in the extraction plugin.
This is the file name if you decide to save the Cryptomatte as a separate file. This supports all the variables.
This is the compression to use for the separate file, the options are identical to the compression settings for the main Cryptomatte file.
The Manifest stores the metadata that allows the extraction plugins in the compositing application to match individual mattes to their names and vice versa. It may be stored within the OpenEXR image, or as a side car file next to it.
You have four options:
This external file needs to be written manually using either the Write All Manifests or the Write Manifest button.
The file name for an external manifest, used if the manifest is either External per Frame or One External File.
Writes the manifests for all Cryptomatte types that are set to One External File.
Writes the manifest for the Cryptomatte type if it is set to One External File.