Function initThree

Returns {
    addUserGeometry: (object: Object3D) => void;
    applyEdges: (root: Object3D) => void;
    camera: PerspectiveCamera;
    cameraController: CameraController;
    clearSelection: () => void;
    clearUserGeometry: () => void;
    controls: OrbitControls;
    dispose: () => void;
    fitToView: () => void;
    gizmo: ViewGizmo | null;
    grid: Grid | null;
    measureTool: MeasureTool | null;
    removeUserGeometry: (object: Object3D) => void;
    renderer: WebGLRenderer;
    scene: Scene;
    setAmbientOcclusion: (enabled: boolean) => void;
    updateShadowBounds: () => void;
}

• addUserGeometry: (object: Object3D) => void

  Add caller-owned geometry (lines, annotations, construction aids) to the scene. The object is tagged userData.source = 'user' so it persists across updateScene solves instead of being cleared with compute content. It is treated as normal content for fit-to-view framing.

• applyEdges: (root: Object3D) => void

  Attach edge overlays to the meshes under root (no-op unless edges.enabled). Call after loading meshes via updateScene, since meshes arrive after init.

• camera: PerspectiveCamera

• cameraController: CameraController

• clearSelection: () => void

• clearUserGeometry: () => void

  Remove and dispose all user-added geometry (every object tagged source === 'user').

• controls: OrbitControls

• dispose: () => void

• fitToView: () => void

• gizmo: ViewGizmo | null

• grid: Grid | null

• measureTool: MeasureTool | null

  Two-click distance measurement tool. Null unless measure.enabled; setEnabled(true) to use.

• removeUserGeometry: (object: Object3D) => void

  Remove a single user-added object and dispose its geometry/materials.

• renderer: WebGLRenderer

• scene: Scene

• setAmbientOcclusion: (enabled: boolean) => void

  Toggle ambient occlusion at runtime — builds or tears down the postprocessing pipeline.

• updateShadowBounds: () => void

  Refit the sun's shadow frustum to the current scene content for crisp shadows. Call after loading or replacing geometry (e.g. after updateScene). No-op when sunlight/shadows are off.