Godot 3D Prop Integration

Bring an externally authored prop (typically a GLB from Blender) into a Godot 4 scene so it reads well at gameplay distance and behaves like the object it replaces. Use for hero props, furniture, and fixtures — not for procedural geometry or character rigs.

Workflow

1. Confirm the read first. Check the silhouette at the actual gameplay

camera distance and lighting before tuning detail. A prop that only reads in a close-up inspector view is not done.

1. Fix real-world measure. Model in meters, set the pivot at the placement

point (usually floor center), and agree on one front axis per prop family (e.g. screens face +X). Record footprint, height, and facing with the asset.

1. Separate source, export, and runtime. Keep editable sources and

previews apart from exported GLBs, and import GLBs into scenes rather than editing them in place. Re-export must be reproducible from source alone.

1. Share resources across instances. Repeated placements share imported

meshes and materials. Never mutate a shared material per instance — use per-instance uniforms or a duplicated material only where variation is genuinely needed.

1. Group collision deliberately. Use a few simple shapes sized to the

visible mesh. Leave genuine openings open (staff wells, entries, walkable ramps); collision must match what the player sees, including open lids.

1. Preserve behavior. If the prop replaces a primitive, carry over

animation, interaction callbacks, lights, and shaders. Remove the old bodies so there are no duplicate colliders.

For the import checklist (budgets, degeneracy, orientation audits), read references/prop_checklist.md.

Adaptation criteria

Triangle budgets, surface counts, LOD policy, and front-axis conventions are project choices — set them from your scene's measured cost, not from another game's numbers. Small background props need far less than hero pieces the camera lingers on.

Common failures

• Buried or floating placement because the pivot is not at the support surface.
• Mirrored or backwards facing from an unrecorded front axis.
• Per-instance material tweaks leaking across all instances via a shared resource.
• Heavyweight collision (concave or per-triangle) where grouped boxes suffice.
• Provenance drift: runtime GLB edited without updating the editable source.
• Reference-photo pixels shipped without appropriate reuse rights or provenance.

Verification

• Headless checks prove structure only: mesh budgets, finite attributes,

zero-area triangles, collider coverage, callback wiring, no overlapping placements. They say nothing about how the prop looks.

• Rendered proof needs two views: an isolated studio-style capture of the

prop, and a capture of it in its real room with production lighting. Review both before calling the integration done.

Example invocations

• "Use $godot-3d-prop-integration to replace the break-room vending machine

primitive with the authored GLB, keeping its interaction."

• "Use $godot-3d-prop-integration to review why these kiosk instances all

change color when one is highlighted."