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Export a scene from Unreal Engine as both a Gaussian splat (for the environment) and a USD file (for foreground mesh geometry), then bring them into Spark Story.

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1. Separate foreground elements

Identify which objects in your scene need to stay as mesh geometry — anything with fine detail the splat might miss, or elements you may want to shoot through (railings, stairs, furniture).
  1. In the Unreal Editor, open the Layers panel.
  2. Add a new layer and name it Mesh.
  3. Drag the foreground elements you want to keep as mesh geometry into this layer (e.g., tables, chairs, railings, staircases).

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2. Add scene locators

Scene locators mark positions in the scene where you want to place actors or quickly jump to during previs.
  1. Add an empty actor to the scene.
  2. Rename it using the naming convention Scene_Lock_01 (replace 01 with a descriptive name or number).
  3. Position it where you want the first locator.
  4. Alt+drag the actor to duplicate it and create additional locators at other key positions.
  5. Add the scene locators to your Mesh layer so they export with the foreground elements.

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3. Install the USD exporter plugin

  1. Go to Edit > Plugins.
  2. Search for USD Importer (this plugin handles both import and export).
  3. Enable the plugin.
  4. Restart Unreal Engine.

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4. Export as USD

  1. Select the Mesh layer (double-click it to select all its contents, including the scene locators).
  2. Go to File > Export Selected.
  3. Choose USD from the file type dropdown.
  4. In the USD export settings, enable Bake Materials.
  5. Expand the material settings menus and remove any generated elements you don’t need.
  6. Click Export.

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5. Render a panoramic 360 image

Render a single panoramic frame from Unreal Engine to use as the source for your Gaussian splat.
  1. Go to Edit > Plugins and enable Additional Render Passes.
  2. Add a Camera actor to the scene and position it in the center of your environment.
  3. Open the Sequencer, drag your camera in, and set the in and out points so it renders a single frame.
  4. Add a Media Render Cube to the sequence.
  5. In the render settings, delete the default Deferred Rendering pass.
  6. Go to Settings > Panoramic Rendering and enable Allocate History Per Pane. Without this, the render will come out too dark.
  7. Add any anti-aliasing settings you need.
  8. Set the output resolution to 4096 x 2048 (2:1 aspect ratio).
  9. Render the frame.

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6. Convert to a Gaussian splat with World Labs

  1. Open World Labs and choose 2D Input.
  2. Drag and drop your panoramic render into World Labs.
  3. World Labs generates a Gaussian splat from the image, preserving the lighting from your Unreal scene.
  4. Download the result as a PLY file.

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7. Import into Spark Story

Bring both the Gaussian splat and the USD foreground elements into Spark Story.
  1. In Spark Story, click Add and choose Location.
  2. Upload your PLY Gaussian splat file. This becomes the environment background with baked lighting.
  3. Click Add again and choose Object.
  4. Import your USD or USDZ file containing the foreground elements (tables, chairs, staircase, etc.).
The final scene combines mesh detail for foreground elements with a Gaussian splat background that preserves the original Unreal Engine lighting.