Orso

Install the app

Run the Orso installer and it places Orso in your Applications folder. The first time you open it, macOS confirms it's from an identified developer (Pixel Bear LLC) — click Open. The orso command-line tool installs alongside it.

Requires macOS 13 (Ventura) or later. Universal — runs natively on Apple silicon and Intel.

Open your footage

Three ways to load a shot:

• Drag a sequence folder — or a single frame — onto the viewer.
• File ▸ Open… (⌘O) and choose a folder or one frame.
• Click Open in the toolbar.

Orso scans the folder and groups frames into sequences automatically. If it finds several, it asks "This folder has N sequences" — pick one, or choose Open All in Tabs to load each in its own window tab. Point it at a single frame and it still follows the whole #### sequence on the timeline.

What Orso reads

Orso detects the kind of pass automatically and adapts the controls:

Cryptomatte EXR

The standard Cryptomatte format (Nuke, Blender, Arnold, Redshift, Karma, C4D…). You get a searchable object checklist of named objects, materials, or assets.

Puzzle / ID pass EXR · PNG · TIFF · JPEG · HEIC…

A puzzle-matte or object/material AOV of flat colors or channels. You select by channel, by keying a flat color (click it in the viewer), and tune a Color Tolerance.

Empty areas both modes

Turn on Empty areas (no ID) to grab the holdout / background — the blank regions where no object exists. It combines with your other picks.

Pick your objects

Tick objects in the sidebar, or click them right in the viewer. The click grammar is the same everywhere:

The status line echoes what you picked, and the sidebar footer shows the count with a Clear button. Use the Filter objects field to find a name fast in a busy manifest.

Preview & scrub

Toggle the viewer between ID Colors (the false-color object map, with your selection popped to white) and Matte (the grayscale coverage you'll bake). Step frames with the arrows, drag the scrubber, or read the frame / total counter. The whole sequence pre-warms in the background so playback stays fluid.

Choose the output

The inspector's Matte and Deliver As sections decide what gets written:

Style

Luma — a grayscale matte to use as a luma mask. Alpha — white with the matte in the alpha channel, plus a mode: Premultiplied (Black) (what Motion & FCP expect), Premultiplied (White), or Straight.

Deliver as — Movie

Pick a Codec (ProRes 4444 XQ / 4444 / 422 family, HEVC with Alpha, HEVC, H.264), a Container (.mov / .mp4 / .m4v), and a Frame Rate. For transparency, choose ProRes 4444, 4444 XQ, or HEVC (with Alpha).

Deliver as — Image Sequence

PNG (8-bit), PNG (16-bit), or TIFF (16-bit). Sequences carry no frame rate — Motion assigns the project rate on import.

Output folder

Bakes go to your global output folder (set in Settings, ⌘,) unless you turn on Override and choose a folder for this matte.

Bake

Click Bake Movie… / Bake Sequence… (⌘B), choose where to save, and Orso renders every frame and reveals the result in Finder. Working on several shots at once? Bake All Open… (⌘⌥B) renders every open tab — one at a time or all at once, set in Settings.

Menus & shortcuts

The toolbar's Objects and Settings buttons show or hide the side panels.

The orso command line

Everything the app bakes, the orso tool can do headless — ideal for render farms and batch jobs. It shares the exact same engine.

List what's inside a render:

orso list /renders/shot01/

Bake a matte — cryptomatte objects to a ProRes 4444 movie with alpha:

orso bake /renders/shot01/ \
  --objects "Hero,Ground" --out matte.mov \
  --movie prores4444 --style alpha --alpha-mode black --fps 24

Key an ID pass by color, to a 16-bit TIFF sequence:

orso bake idpass.png --colors "1,0,0;0,1,0" --tolerance 0.08 \
  --out mattes/ --sequence tiff16 --force

Run many jobs from a JSON file:

orso bake --jobs batch.json

Run orso help for the full flag list — selection (--objects, --all-objects, --channels, --colors, --empty), output (--style, --movie, --container, --fps, --sequence), and --force.

Install the plug-in

The Orso installer installs the Motion filter for you and registers it. If you install Motion later, run the installer again (or tick the Motion plug-in component) to add it. Restart Motion after installing.

The plug-in is a companion to the app — you can use either or both. It requires an FxPlug host (Apple Motion or a compatible Creator Studio host).

Apply the filter

In Motion, add the filter to your layer from Filters ▸ Pixel Bear ▸ Orso. It appears in the Inspector like any other filter.

Point it at your EXR

Orso needs to know which Cryptomatte sequence to read. Any of:

• Automatic — leave the path empty and Orso discovers the newest Cryptomatte sequence you have open.
• Choose EXR… — pick any single frame of the sequence; Orso promotes it to the full #### sequence and follows the timeline.
• Paste a path into or paste path here — a frame or a #### pattern.

Pick your IDs

1. Click ID Picker to open the picker window: a preview you click objects on, kept in sync with a searchable matte checklist. Filter with the search field, refresh the manifest with ↻, or Clear to deselect all.
2. Or pick on the canvas: with the filter selected, click an object to toggle its matte, or drag to paint-add several. A small cyan badge shows picking is armed.
3. Click a blank area to add the Empty / No-ID holdout to the selection.

Every pick is written to the Selected IDs list in the Inspector — one object name per line. You can hand-edit that list too.

The controls

ID Picker

Opens the visual picker window.

Choose EXR… / or paste path here

Set the Cryptomatte sequence to read.

Crypto Layer

Auto (First in File), or force CryptoObject, CryptoMaterial, CryptoAsset, CryptoMesh, or a Custom… layer name.

Output

Matte — the grayscale coverage. Cutout (RGBA × Matte) — the layer masked by the matte. ID Preview — the false-color map for picking.

Invert Matte

Flip the selection inside-out.

Flip Vertical

On by default — matches EXR row order to Motion. Turn off if your matte is upside-down.

Frame Offset

Nudge which EXR frame lines up with the timeline if your render and comp start on different frame numbers.

Selected IDs

The editable list of picked objects, one per line.

Clear Selection

Empties the Selected IDs list.

Notes & limits

• The plug-in reads the EXR from disk itself — Motion doesn't pass Cryptomatte layers through the filter, so it always needs a valid path (auto-discovered or set).
• On the current Motion build the rich UI opens in its own picker window rather than inline in the Inspector — that's expected.
• Rendered mattes are cached for smooth, looped playback; a change to any control re-renders as needed.
• For Final Cut Pro, bake your matte with the app (or the orso CLI) and import it — FCP delivery is the app's job, live matteing is Motion's.