Assets And Importing
Assets are reusable resources used by scenes and graphs. Images, audio clips, prefabs, character rigs, generated cutouts, and .ssb sprite sequence bundles live in the asset library so you can place them, assign them, animate them, or spawn them later.
Asset Library
Open the Assets dock tab. Use New for a scene, prefab, folder, or primitive; Import accepts files or an asset pack.
New assets are filed automatically when you import into the project root or save from a creation tool. Drop into a specific folder to choose a different destination.
| Folder | Typical contents |
|---|---|
| Scenes | Project scenes |
| Art | Images, baked frames, tiles, and editable .opix pixel documents |
| Animations | .ssb sprite sequence bundles |
| Audio | Imported or generated sound effects and music |
| VFX | .pfx particle effects |
| Characters | Rigged character assets |
| Prefabs | Prefabs and variants |
| Scripts | Imported script files; project and scene scripts are edited in Script Studio |
| Behaviors | .opbrain behavior assets |
| Definitions | .opdef definition assets |
| Backgrounds | Assets explicitly marked as backgrounds |
| UI | Fonts and assets explicitly marked for UI |
| Imported | Other file types |
The project root shows all assets. Folder links beneath grid cards show their location and jump into that folder. Use the folder tree for browsing and the search box for names or folder paths. Choose Current folder or Entire project beside search. Filter limits asset types; an empty result offers to clear the search and filters. Thumbnail sizing is available in Grid; List prioritizes names and metadata.
Drag assets into folders to organize them further. Saving or re-baking an existing asset keeps its current folder and ID, including custom folders. New copies use the standard folders unless you choose a destination. Existing projects and imported asset-pack folders keep their arrangement; opening a project does not automatically move its files.
Importing Images
Use the Add menu:
| Command | Result |
|---|---|
| Add -> Add Art | Import image files and place them into the current scene immediately |
| Add -> Library | Import image files into the asset library without placing them |
PNG, JPEG, WebP, and SVG are the safest image choices. Browser support decides the final set of image formats.
Placing And Assigning Assets
| Action | Result |
|---|---|
| Click an asset | Inspect its preview, details, and available actions |
| Double-click, press Enter, or use the primary action | Perform the displayed type-specific action: place an image, open a drawing or scene, preview sound, or edit supported content |
| Drag from the library | Place it or assign it, depending on the target |
| Select object and choose art | Replace the selected object's image |
| Place a prefab/blueprint | Create a new instance from the template |
Use a .ssb bundle in Flow | Play or swap sprite-sequence animation at runtime |
After placement, the scene object stores its transform and inspector fields while the project library keeps the shared asset record.
Show dependencies opens the asset in Graph. Selecting a graph node keeps you in the map; its explicit open action reveals the source asset. Sounds and document files cannot be placed as image sprites.
Cutting Sprites Out Of Photos
Open Pixels and use its Cutout menu. It replaces the old standalone cutout page, so everything happens on a normal pixel document with undo. The full drawing, layer, frame, and bake reference is Pixel Studio.
| Step | Use |
|---|---|
File → Open… (Ctrl/Cmd+O) | Open a PNG, JPEG, WebP, GIF, .opix or Aseprite file from disk, or drop one on the canvas. Library images open from the Assets tab. The Cutout menu's Import limit scales large photos down on the way in |
File → Place… (Ctrl/Cmd+Shift+O) | Put an image from disk on a new layer of the open document (also in the Layers panel, or Shift-drop on the canvas). A bigger image grows the canvas rather than being clipped |
| Remove background | Runs a model on Opal's servers (rembg, BEN2, or Apple Vision) against the active layer |
| Magic Wand with Contiguous off | Selects one colour everywhere; press Delete to key it out |
| Crop to selection / Trim to art | Crop the canvas to a selection, or to the drawn pixels across every frame |
| File → Export PNG or Bake → Bake PNG | Write PNG sprites to Assets › Art. A still of an opened library image replaces that image. Export PNG reveals the first sprite. This does not write an .ssb or a .opix |
| Bake → Bake animation | Write PNG frames to Art and an .ssb to Animations. Needs two or more drawing frames. Re-bakes keep any custom locations |
| File → Save | Keep the .opix working file (layers, frames, palette). Save is the only way to create that file — bake does not |
Background removal runs on Opal's servers. Import, crop, trim, and the wand still work if removal is unavailable.
Art Canvas And .ssb Bundles
Use the Art workspace when an asset should become a frame animation:
| Source | Typical pipeline |
|---|---|
| Sprite sheet | Image -> Slice Sheet -> Animation -> Preview -> Save .ssb |
| Loose frames | Sprites -> Animation -> Preview -> Save .ssb |
| Existing bundle | Sprite Sequence -> Animation -> Preview -> Save .ssb |
Saved .ssb bundles appear in the asset library. Inspect their details there, then use them from Sprite Animator or Object Flow Sprite Sequence nodes. They cannot be placed as image sprites.
Playback waits for the clip's frame images before starting its clock. A one-shot Play Animation node follows its outgoing Flow wire after the clip finishes, including per-frame holds. A looping clip continues the Flow immediately. If a frame is unavailable, the clip reports a diagnostic instead of silently skipping it.
See Pixel Studio, Art Canvas, Skeleton Studio, and Motion and rigging.
Importing Sounds
Use Add -> Sounds to import or manage audio clips. Imported clips can be used by Flow graph actions, scene-level music controls, or as source material in Sound Canvas.
Good sound workflow:
- Import short sound effects for taps, hits, pickups, and UI feedback — or record them from the Sounds modal or a Sound Canvas Mic node.
- Rename clips clearly in the asset library.
- Optional: open Sound Canvas to trim, layer, normalize, or bake variants before wiring gameplay.
- Trigger effects from Object Flow with Play audio.
- Keep background music scene-level when it applies to a whole level or menu.
See Sound Canvas for composing and baking WAV assets.
Particle Effects
Built-in names (sparkle, smoke, fire, …) are enough for many one-shots. Use Create ▾ → FX when you want a custom look: compose an emitter chain, preview it, and Save a .pfx. Play it from Spawn VFX, a Particle Emitter, or a motion marker.
See Particle Canvas and Audio and VFX.
Importing Scenes And Projects
Use File -> Import Scene... to load a scene file into the current project.
Use File -> Open Project... to load a .opal project bundle exported with File -> Export Game.
Use File -> Export Scene and File -> Export Game for backups and sharing. See Sharing and publishing.
Prefabs And Blueprints
Prefabs appear in the library as reusable object templates. They are best for content that must appear multiple times with the same structure or behavior.
Examples:
- Enemy with Health, Motion, and Object Flow
- Coin pickup with a sound and score event
- Door that loads another scene
- HUD counter connected to GameState
- Spawner marker with configured spawn settings
If you change the source prefab, instances can update automatically unless an instance has manual overrides.
Asset Organization
Good names prevent confusion in larger games.
| Weak name | Better name |
|---|---|
image1 | player_idle |
new-sound | sfx_coin_pickup |
button | ui_button_primary |
enemy | enemy_slime_prefab |
Animation | player_walk_right |
Prefer names based on role, not visual guesswork. A file called level_1_exit_door is easier to find than brown_rectangle.