import { Group, Vector3, Plane, Scene } from 'three';
export declare class PathMeasure3d {
    group: Group;
    private pointsGizmo;
    private pathLines;
    private projLines;
    /** Fixed path vertices. */
    points: Vector3[];
    firstNormal: Vector3;
    projectionPlane: Plane;
    /** Last confirmed or mouse-hover point — used to anchor the label callout. */
    lastActivePoint: Vector3;
    /** Total path length in mm (for the UI label). */
    totalLengthText: number;
    /** Projected path length in mm (for the UI label). */
    totalProjLengthText: number;
    /** Screen position of the UI label. */
    labelX: number;
    labelY: number;
    lastSegmentCenter: Vector3;
    constructor(helpersScene: Scene);
    setProjectionPlane(plane: Plane): void;
    /** Reset geometry via .clear() without destroying the underlying geometry objects. */
    reset(): void;
    /** Add a confirmed click point to the path. */
    addPoint(point: Vector3, normal?: Vector3): void;
    private renderPath;
    /** Update the UI label position to the midpoint of the last path segment. */
    updateLabel(viewerElement: any, camera: any): void;
    /** Release all GPU resources. */
    dispose(): void;
}