How to Move Marble 3D Worlds into Unity or Unreal

Getting a Marble world into an engine takes three passes: export the mesh, fix scale and collision, then rebake lighting. Drop the raw export into Unity unchanged and you get a scene that looks right in the editor and performs badly at runtime.

This follows the basic walkthrough for World Labs Marble. It assumes you have a world you like and now need it playable.

What format should you export?

Take a mesh format your engine imports natively — glTF or FBX — rather than a proprietary scene file. glTF is the safer bet across Unity, Unreal and web viewers, and it carries materials in one file.

Export at the highest texture resolution available. Downscaling later is easy; recovering detail from an already-compressed texture is not.

Why is the scale always wrong in the engine?

Because generated worlds come in their own units, and your engine expects meters. A doorway that looks human-sized in the Marble viewer can import at ten times scale.

Fix it before doing anything else:

1. Import the mesh into a test scene with a 1-meter reference cube.
2. Scale the root object until a doorway or person-height ledge reads correctly.
3. Apply the transform so the scale is baked into vertices, not left on the node.

Unity treats 1 unit as 1 meter; Unreal treats 1 unit as 1 centimeter. That difference alone causes most “giant world” imports.

How do you handle collision?

Do not use the full generated mesh as a collider. The triangle count is enormous and the physics engine will choke. Generate a simple collider instead:

• Use a coarse convex decomposition or a box/primitive collider set for walls.
• Add an invisible floor plane for walking surfaces rather than relying on raw geometry.
• Delete geometry outside the playable area — decorative detail the player never reaches still costs collision budget.

A scene that renders fine can still drop frames purely from collision, so treat this as a required step, not an optimization.

What about lighting and materials?

Generated worlds often ship with baked-in shading in the textures. If you add real-time lights on top, the scene looks muddy — light from two sources fighting.

Either rebake lighting for your engine’s pipeline, or regenerate the world with flatter, more neutral base colors if the tool allows. Baking once in the engine gives you consistent shadows across the whole level instead of shadows frozen into texture from the original viewpoint.

When is this pipeline not worth it?

When the camera stays fixed or the environment is a backdrop behind a cutscene. In that case a rendered image or video is cheaper and looks better than a walkable mesh you have to clean up. Reserve the engine pipeline for places the player can actually explore.

Quick Summary

• Export glTF or FBX at maximum texture resolution.
• Fix scale against a 1-meter reference before anything else.
• Never use the raw mesh as a collider — build simple collision around it.
• Rebake lighting; baked-in shading fights real-time lights.
• Skip the pipeline entirely for fixed-camera backdrops — use a video instead.