import { Object3D } from 'three/webgpu';
/**
 * Loader for STEP, STP, IGES, and IGS CAD files using occt-import-js.
 * Parsing runs in a blob-URL Web Worker (same pattern as DracoLoader).
 * Converts OpenCASCADE output to Three.js Object3D hierarchy.
 */
export declare class STEPLoader {
    private _workerPending;
    private _worker;
    private _nextId;
    private _pending;
    /**
     * Create (or return existing) blob-URL worker.
     * Loads occt-import-js JS as raw text, concatenates with STEPWorker
     * function body, and creates a classic (non-module) worker.
     */
    private _getWorker;
    /**
     * Parse STEP or IGES file content and return a Three.js Object3D
     */
    parseAsync(arrayBuffer: ArrayBuffer, fileType: 'step' | 'stp' | 'iges' | 'igs'): Promise<Object3D>;
    /**
     * Dispose the worker. Call when the loader is no longer needed.
     */
    dispose(): void;
    private _buildScene;
    private _buildNode;
    private _createMesh;
}