2.4 KiB
ADR 0017: Normalized Static Mesh Assets
Status
Accepted
Context
glTF/GLB and FBX previously entered the editor as imported scenes through ModelRef, with runtime hydration loading a format-specific SceneRoot. That path is still useful for full scene playback, but it makes ordinary static mesh placement depend on source format behavior and prevents the inspector from exposing a stable renderer component.
The editor needs model drag/drop to create editable static mesh actors by default, while retaining an explicit scene-instance path for animation, skinning, cameras, and other full-scene data.
Decision
Model imports now generate deterministic project artifacts under assets/meshes/generated/*.static_mesh.ron. The artifact records stable part IDs, source path, format, source fingerprint, import settings, mesh/material subasset labels, source node/material metadata, dependency paths, and warnings for metadata that is not played by the static mesh path.
The saved scene authoring component is StaticMeshRenderer. Its slots reference imported mesh/material assets by EditorAssetRef (asset_id + sub_asset_id) rather than source file paths. Hydration resolves those refs through the generated artifact, spawns runtime child Mesh3d parts, and strips/regenerates them like other hydrated ECS. Built-in primitives remain Primitive, and explicit full-scene placement remains ImportedModel + ModelRef.
Asset import settings choose the default placement mode:
StaticAssetcreatesActorKind::StaticMesh + StaticMeshRenderer; when collider generation is enabled it also createsRigidBodyDesc + ColliderDesc::StaticMesh.SceneInstancecreates the legacyActorKind::ImportedModel + ModelRef.
Hierarchy mode is also stored per asset. SingleActor places all mesh parts into one renderer. SourceHierarchy creates an authored root with child static mesh actors.
Consequences
- glTF/GLB and FBX placement consume the same renderer contract after processing.
- Scene files store renderer intent, not runtime Bevy mesh/material handles.
- Static mesh actors can expose renderer slots, source labels, shadows, collider policy, and material overrides in the inspector.
- Animated/skinned playback remains on the scene-instance path until a future animation authoring component exists.
- Generated artifacts are project files but are hidden from the Asset Browser catalog to avoid treating them as levels/prefabs.