The Spark web app supports the following 3D file formats for locations:
- USD — Universal Scene Description
- USDZ — Compressed USD package
- PLY — Polygon file format (commonly used for Gaussian splats and photogrammetry scans)
- SPLAT — Compressed 8-bit splat format
- SPZ — Compressed Gaussian splat format
For a location, the upload window accepts files ending in .ply, .splat, .spz, .usd, .usdc, .usda, and .usdz.
Adding location files
In the Outliner panel, click + on the Locations row. The Asset Library opens with the categories Locations, Objects, and Audio on the left. To bring in a new environment, click Add to Library in the upper right and select your file. To reuse something already in the production, click an existing asset tile.
Adding a USD set
A location does not have to be a splat. You can use a modelled set saved as .usd, .usda, .usdc, or .usdz.
- In the Outliner panel, click + on the Locations row.
- Click Add to Library and select the USD file.
- Check the hints in the upload window. Beside Transformation, it shows the up axis it read from the file, such as “Detected: Z-Up”. Under Select Scale Reference, it shows the unit, such as “Detected: centimeters”.
- Confirm. The set appears on the 3D canvas and is drawn the way an object is.
The splat-only controls are hidden for a USD set: Cull Y in Top-Down View and the Splat Quality buttons in the location’s properties.
If the USD file has animation, the location has an Animation row in the Outliner. Click Add to timeline at playhead on that row to place the animation as a clip on the timeline. It then plays with the scene, like an object’s animation.
Upload vs Load Locally
- Upload writes the file to your production library. Every teammate in the production gains access to it.
- Load Locally loads a file from your local drive for the current session only. Collaborators opening the same scene will not see it.
Use Load Locally for quick personal tests. Use Upload for anything the team needs.
Orientation and scale
Fixing orientation
After importing, fix orientation in the Location Settings panel:
- Invert Up (Flip 180°) — Toggle if the splat loaded upside down.
- Z-Up (Blender/3ds Max) — Toggle if the splat came out of Blender or 3ds Max with the wrong up axis.
- Position and Rotation fields — Type values into the X, Y, Z fields for finer correction.
Setting scale
Click Add Reference in the Scale Reference section. Two methods are available:
- Ruler tool — Click two points on a feature whose real-world size you know (for example, the top of a doorway and the floor). Spark displays the measured distance in your chosen unit. If the reading is wrong, type the correct real-world dimension into the field and Spark rescales the splat to match.
- Six-foot human figure — Drop it into the scene and compare the splat against a known human height.
Scale controls
Once a reference is added, the scale controls become active. The row reads x0.1, -1, -0.1, numeric field, +0.1, +1, x10. Use x0.1 and x10 for large jumps, the +/-1 and +/-0.1 buttons for fine steps, or type a value directly into the field.
Scale errors cascade. Every camera distance, lens choice, and composited actor downstream depends on scale being correct. Getting it right at upload saves rework later.
Collision mesh
Optionally, add a collision mesh by clicking Select GLB file. The collision mesh defines physics collision boundaries for the location.
Splat size guidance
The Spark web app handles very large splats. Files up to 7 GB have rendered in the browser with no hard maximum confirmed. The Spark iOS app caps at roughly 5 million splats per scene — if your splat exceeds that count, the scene will not load on the phone. Keep a downsampled version for mobile previs.
File caching
Imported files are cached for faster loading on subsequent visits. Large assets may take a moment to load the first time they are added to a scene. 
