Cryptomatte

Cryptomatte in DaVinci Resolve/Fusion is a native Studio workflow for post-selecting objects and materials from CG renders. Resolve 20 introduced native Cryptomatte support that reads embedded mattes and metadata from EXR sources.

The source must actually contain compatible Cryptomatte layers plus manifest/metadata. A PNG, JPEG, H.264 file or ordinary EXR does not become Cryptomatte merely by connecting it to this node.

Cryptomatte is not object detection, semantic segmentation or tracking. Names and coverage are authored at render time; Fusion interprets that stored data.

In Resolve 21, Renderer3D using the Hardware Renderer can generate object/material Cryptomatte layers and metadata. That is an upstream render step; the Cryptomatte node remains a downstream reader and selector.

The node has one 2D image input and one 2D image output. Even View Mode = Matte remains an image representation until you explicitly convert it to a mask or use an alpha workflow.

When a downstream tool expects a real Effect Mask, a clear topology is Cryptomatte in Matte mode into Bitmap, then Bitmap.Mask into the blue Effect Mask socket.

View Layer chooses the Cryptomatte layer/matte type used for inspection and selection, such as Object or Material when those namespaces were written by the renderer. The Resolve 20 guide described this control as Layer.

If the expected Object or Material layer is missing, diagnose the source, metadata and render settings before trying to repair the problem with Pick or View Mode.

View Mode = Colors displays ID regions as technical colors. Those colors are for selection and diagnostics; they are not beauty RGB values.

View Mode = Edges shows the source image with Cryptomatte boundary diagnostics. It is not an edge-detection effect such as EdgeDetect.

View Mode = Beauty displays the normal source beauty and is useful for locating the subject, but it does not prove matte quality.

View Mode = Matte displays current selected coverage. Gray values around antialiasing, motion blur, depth of field and transparency can be correct and should not be clipped automatically.

Output to Alpha routes the selected Cryptomatte into alpha in the captured current Inspector. Verify the exact RGB-plus-alpha behavior on the target build before production automation.

Pick maps a visual Viewer location to a Cryptomatte entry. Blackmagic also documents an eyedropper-style drag workflow; always verify the result in Selected Matte List.

Mode = Add includes the picked entry in the current matte and can assemble one selection from multiple objects or materials.

Mode = Remove excludes the picked entry. It changes selection membership rather than globally inverting the matte.

Selected Matte List is the authoritative list of included entries and the clearest audit trail for manual Pick/Add/Remove work.

Clear removes selected entries, while Clear All empties the complete Selected Matte List. They are different reset scopes.

Clear Selected Layer removes all selected mattes that belong to the current Cryptomatte layer. It is not a command for deleting one current list row.

Resolve 20.1 added Expression for regular-expression based selection, which is useful with stable production naming such as car_body_*, glass_* or crowd_*.

Expression is best understood as regex selection over named Cryptomatte entries rather than a generic field for typing raw hashes or IDs.

Matte Layers = Selected/View/All changes the scope used for selection and inspection. It does not change the physical type of the output port.

A major Cryptomatte advantage is renderer-authored coverage: antialiasing, motion-blur and depth-of-field contributions are generally more useful than a hard object-ID mask.

Preserve multilayer EXR data and metadata through the pipeline. A transcode can look identical in beauty RGB while silently destroying the data Cryptomatte needs.

For EXRs from an external DCC or renderer, inspect the actual layer names and manifest. A filename or renderer checkbox alone does not prove that compatible data reached Fusion.

Stable meaningful object/material names make Pick, Selected Matte List and regex Expression reproducible instead of opaque technical selections.

Colors, Edges, Beauty and Matte are diagnostic representations of the same workflow. Do not accidentally deliver a diagnostic Colors or Matte view as final beauty.

When a correction needs beauty RGB and a matte separately, keep the beauty branch independent and convert the Cryptomatte selection through Bitmap or a deliberately verified alpha workflow.

For scripting, never guess internal control IDs from display labels. Confirm serialization by exporting a .setting/.comp on the target Resolve build.