Exporting with a CryptoMatte-Write Node

Once all the Port Names are applied, the main composite can be linked to a CryptoMatte-Write Node. This node can be found in the Node library.

  1. In the Node library, search for CryptoMatte-Write Node.

  2. Drag CryptoMatte-Write Node into the Node view.

  3. Link to the composite with the assets you wish to export as an EXR.

Unlike with Port Filtering, you do not need to use Port Filters or link a port for every Port Name. The CryptoMatte-Write Node will search all accessible nodes connected to the right-most port and will create mattes and IDs automatically. The CryptoMatte-Write Node can also be used to export custom named outputs by creating new ports and attaching other image connections. These other ports will not be considered in the CryptoMatte, but can provide a custom name in the Layer Properties.

In order for the CryptoMatte-Write Node to recognize the other connections, it can be linked one of two ways.

  • Link to the main composite and apply a Port Filter on the input of the CryptoMatte-Write Node linking the desired Port Name.

  • Link the asset directly to the CryptoMatte-Write Node.

CryptoMatte-Write Node Export Settings

Once the CryptoMatte-Write Node is linked to the composite, you are ready to adjust the export settings. You can access the settings by clicking on the yellow square on the CryptoMatte-Write Node.

When the Layer Properties are opened, there will be three tabs.

The three tabs are the following:

  • Inputs

  • Outputs

  • Enabling

Inputs

The Input tab will display all the input connections that are linked to the CryptoMatte-Write Node. The input ports will be listed from right to left. When exporting an EXR, the right-most port will compile all the layers to create the CryptoMatte for the EXR file.

NOTE The rightmost port will appear in green and be named composite. This name cannot be changed in the Inputs tab. This rightmost composite output will be used to create the default RGBA composite in the EXR.

For more information about Inputs, see: Multi-Layer Write Nodes.

Output

The Output tab can be used to configure the path, file naming pattern and file type of frames exported by the Write Node. The CryptoMatte Node only supports the EXR output format, and it cannot be used to export movies.

The Colours section is going to be set by default to Colour + Alpha. When importing your exported EXR into another software, it is important to remember that Harmony will author the CryptoMatte with a transparency Premultiplied with black. This setting cannot be changed.

In addition, there are two additional options in the CryptoMatte-Write Node that differ from other Write Nodes. The CryptoMatte Name and CryptoMatte Image Count.

  • The CryptoMatte Name allows you to rename the CryptoMatte channels in the rendered image.

  • The CryptoMatte Image Count defines the number of CryptoMatte images that will be considered when creating the CryptoMatte in the rendered image. By default, this value is set to three, which will provide three separate CryptoMatte passes in the final rendered image. Three CryptoMatte images will provide six levels of alpha coverage for the CryptoMatte. A higher value will provide more coverage and may be needed if the render contains many overlapping translucent layers.

NOTE For more information about Outputs, see: Write Nodes.

Enabling

You can create several Write nodes for a single scene and, by default, when a scene is rendered, all of its Write nodes will perform their render. However, using the options in the Enabling tab, you can set up some Write nodes to only perform their render if the scene is rendered at a specific resolution. This is mostly useful on Harmony Server, as Harmony Server allows you to select the resolution at which to render a scene when sending a scene for rendering by the Harmony database's render farm.

NOTE For more information about Enabling, see: Write Nodes.