@loaders.gl/tiles/src/tileset/tile-3d.ts

Common components for different tiles loaders.

// loaders.gl
// SPDX-License-Identifier: MIT
// Copyright (c) vis.gl contributors

// This file is derived from the Cesium code base under Apache 2 license
// See LICENSE.md and https://github.com/AnalyticalGraphicsInc/cesium/blob/master/LICENSE.md

import {Vector3, Matrix4} from '@math.gl/core';
import {CullingVolume} from '@math.gl/culling';

import {load} from '@loaders.gl/core';

// Note: circular dependency
import type {Tileset3D} from './tileset-3d';
import type {DoublyLinkedListNode} from '../utils/doubly-linked-list-node';
import {TILE_REFINEMENT, TILE_CONTENT_STATE, TILESET_TYPE} from '../constants';

import {FrameState} from './helpers/frame-state';
import {
  createBoundingVolume,
  getCartographicBounds,
  CartographicBounds
} from './helpers/bounding-volume';
import {getTiles3DScreenSpaceError} from './helpers/tiles-3d-lod';
import {getProjectedRadius} from './helpers/i3s-lod';
import {get3dTilesOptions} from './helpers/3d-tiles-options';
import {TilesetTraverser} from './tileset-traverser';

const scratchVector = new Vector3();

function defined(x) {
  return x !== undefined && x !== null;
}

/**
 * @param tileset - Tileset3D instance
 * @param header - tile header - JSON loaded from a dataset
 * @param parentHeader - parent Tile3D instance
 * @param extendedId - optional ID to separate copies of a tile for different viewports.
 *                              const extendedId = `${tile.id}-${frameState.viewport.id}`;
 */
export type Tile3DProps = {
  tileset: Tileset3D;
  header: Object;
  parentHeader: Tile3D;
  extendedId: string;
};

/**
 * A Tile3DHeader represents a tile as Tileset3D. When a tile is first created, its content is not loaded;
 * the content is loaded on-demand when needed based on the view.
 * Do not construct this directly, instead access tiles through {@link Tileset3D#tileVisible}.
 */
export class Tile3D {
  tileset: Tileset3D;
  header: any;
  id: string;
  url: string;
  parent: Tile3D;
  /* Specifies the type of refine that is used when traversing this tile for rendering. */
  refine: TILE_REFINEMENT;
  type: string;
  contentUrl: string;
  /** Different refinement algorithms used by I3S and 3D tiles */
  lodMetricType: 'geometricError' | 'maxScreenThreshold' = 'geometricError';
  /** The error, in meters, introduced if this tile is rendered and its children are not. */
  lodMetricValue: number = 0;

  /** @todo math.gl is not exporting BoundingVolume base type? */
  boundingVolume: any = null;

  /**
   * The tile's content.  This represents the actual tile's payload,
   * not the content's metadata in the tileset JSON file.
   */
  content: any = null;
  contentState: number = TILE_CONTENT_STATE.UNLOADED;
  gpuMemoryUsageInBytes: number = 0;

  /** The tile's children - an array of Tile3D objects. */
  children: Tile3D[] = [];
  depth: number = 0;
  viewportIds: any[] = [];
  transform = new Matrix4();
  extensions: any = null;
  /** TODO Cesium 3d tiles specific */
  implicitTiling?: any = null;

  /** Container to store application specific data */
  userData: Record<string, any> = {};

  computedTransform: any;
  hasEmptyContent: boolean = false;
  hasTilesetContent: boolean = false;

  traverser = new TilesetTraverser({});

  /** Used by TilesetCache */
  _cacheNode: DoublyLinkedListNode | null = null;

  private _frameNumber: any = null;

  // TODO Cesium 3d tiles specific
  private _expireDate: any = null;
  private _expiredContent: any = null;

  private _boundingBox?: CartographicBounds = undefined;

  /** updated every frame for tree traversal and rendering optimizations: */
  public _distanceToCamera: number = 0;
  _screenSpaceError: number = 0;
  private _visibilityPlaneMask: any;
  private _visible: boolean | undefined = undefined;

  private _contentBoundingVolume: any;
  private _viewerRequestVolume: any;

  _initialTransform: Matrix4 = new Matrix4();

  // Used by traverser, cannot be marked private
  _priority: number = 0;
  _selectedFrame: number = 0;
  _requestedFrame: number = 0;
  _selectionDepth: number = 0;
  _touchedFrame: number = 0;
  _centerZDepth: number = 0;
  _shouldRefine: boolean = false;
  _stackLength: number = 0;
  _visitedFrame: number = 0;
  _inRequestVolume: boolean = false;
  _lodJudge: any = null; // TODO i3s specific, needs to remove

  /**
   * @constructs
   * Create a Tile3D instance
   * @param tileset - Tileset3D instance
   * @param header - tile header - JSON loaded from a dataset
   * @param parentHeader - parent Tile3D instance
   * @param extendedId - optional ID to separate copies of a tile for different viewports.
   *    const extendedId = `${tile.id}-${frameState.viewport.id}`;
   */
  // eslint-disable-next-line max-statements
  constructor(
    tileset: Tileset3D,
    header: {[key: string]: any},
    parentHeader?: Tile3D,
    extendedId = ''
  ) {
    // PUBLIC MEMBERS
    // original tile data
    this.header = header;

    // The tileset containing this tile.
    this.tileset = tileset;
    this.id = extendedId || header.id;
    this.url = header.url;

    // This tile's parent or `undefined` if this tile is the root.
    // @ts-ignore
    this.parent = parentHeader;
    this.refine = this._getRefine(header.refine);
    this.type = header.type;
    this.contentUrl = header.contentUrl;

    this._initializeLodMetric(header);
    this._initializeTransforms(header);
    this._initializeBoundingVolumes(header);
    this._initializeContent(header);
    this._initializeRenderingState(header);

    Object.seal(this);
  }

  destroy() {
    this.header = null;
  }

  isDestroyed() {
    return this.header === null;
  }

  get selected() {
    return this._selectedFrame === this.tileset._frameNumber;
  }

  get isVisible() {
    return this._visible;
  }

  get isVisibleAndInRequestVolume() {
    return this._visible && this._inRequestVolume;
  }

  /** Returns true if tile is not an empty tile and not an external tileset */
  get hasRenderContent() {
    return !this.hasEmptyContent && !this.hasTilesetContent;
  }

  /** Returns true if tile has children */
  get hasChildren() {
    return this.children.length > 0 || (this.header.children && this.header.children.length > 0);
  }

  /**
   * Determines if the tile's content is ready. This is automatically `true` for
   * tiles with empty content.
   */
  get contentReady() {
    return this.contentState === TILE_CONTENT_STATE.READY || this.hasEmptyContent;
  }

  /**
   * Determines if the tile has available content to render.  `true` if the tile's
   * content is ready or if it has expired content this renders while new content loads; otherwise,
   */
  get contentAvailable() {
    return Boolean(
      (this.contentReady && this.hasRenderContent) || (this._expiredContent && !this.contentFailed)
    );
  }

  /** Returns true if tile has renderable content but it's unloaded */
  get hasUnloadedContent() {
    return this.hasRenderContent && this.contentUnloaded;
  }

  /**
   * Determines if the tile's content has not be requested. `true` if tile's
   * content has not be requested; otherwise, `false`.
   */
  get contentUnloaded() {
    return this.contentState === TILE_CONTENT_STATE.UNLOADED;
  }

  /**
   * Determines if the tile's content is expired. `true` if tile's
   * content is expired; otherwise, `false`.
   */
  get contentExpired() {
    return this.contentState === TILE_CONTENT_STATE.EXPIRED;
  }

  // Determines if the tile's content failed to load.  `true` if the tile's
  // content failed to load; otherwise, `false`.
  get contentFailed() {
    return this.contentState === TILE_CONTENT_STATE.FAILED;
  }

  /**
   * Distance from the tile's bounding volume center to the camera
   */
  get distanceToCamera(): number {
    return this._distanceToCamera;
  }

  /**
   * Screen space error for LOD selection
   */
  get screenSpaceError(): number {
    return this._screenSpaceError;
  }

  /**
   * Get bounding box in cartographic coordinates
   * @returns [min, max] each in [longitude, latitude, altitude]
   */
  get boundingBox(): CartographicBounds {
    if (!this._boundingBox) {
      this._boundingBox = getCartographicBounds(this.header.boundingVolume, this.boundingVolume);
    }
    return this._boundingBox;
  }

  /** Get the tile's screen space error. */
  getScreenSpaceError(frameState, useParentLodMetric) {
    switch (this.tileset.type) {
      case TILESET_TYPE.I3S:
        return getProjectedRadius(this, frameState);
      case TILESET_TYPE.TILES3D:
        return getTiles3DScreenSpaceError(this, frameState, useParentLodMetric);
      default:
        // eslint-disable-next-line
        throw new Error('Unsupported tileset type');
    }
  }

  /**
   * Make tile unselected than means it won't be shown
   * but it can be still loaded in memory
   */
  unselect(): void {
    this._selectedFrame = 0;
  }

  /**
   * Memory usage of tile on GPU
   */
  _getGpuMemoryUsageInBytes(): number {
    return this.content.gpuMemoryUsageInBytes || this.content.byteLength || 0;
  }

  /*
   * If skipLevelOfDetail is off try to load child tiles as soon as possible so that their parent can refine sooner.
   * Tiles are prioritized by screen space error.
   */
  // eslint-disable-next-line complexity
  _getPriority() {
    const traverser = this.tileset._traverser;
    const {skipLevelOfDetail} = traverser.options;

    /*
     * Tiles that are outside of the camera's frustum could be skipped if we are in 'ADD' mode
     * or if we are using 'Skip Traversal' in 'REPLACE' mode.
     * Otherewise, all 'touched' child tiles have to be loaded and displayed,
     * this may include tiles that are outide of the camera frustum (so that we can hide the parent tile).
     */
    const maySkipTile = this.refine === TILE_REFINEMENT.ADD || skipLevelOfDetail;

    // Check if any reason to abort
    if (maySkipTile && !this.isVisible && this._visible !== undefined) {
      return -1;
    }
    // Condition used in `cancelOutOfViewRequests` function in CesiumJS/Cesium3DTileset.js
    if (this.tileset._frameNumber - this._touchedFrame >= 1) {
      return -1;
    }
    if (this.contentState === TILE_CONTENT_STATE.UNLOADED) {
      return -1;
    }

    // Based on the priority function `getPriorityReverseScreenSpaceError` in CesiumJS. Scheduling priority is based on the parent's screen space error when possible.
    const parent = this.parent;
    const useParentScreenSpaceError =
      parent && (!maySkipTile || this._screenSpaceError === 0.0 || parent.hasTilesetContent);
    const screenSpaceError = useParentScreenSpaceError
      ? parent._screenSpaceError
      : this._screenSpaceError;

    const rootScreenSpaceError = traverser.root ? traverser.root._screenSpaceError : 0.0;

    // Map higher SSE to lower values (e.g. root tile is highest priority)
    return Math.max(rootScreenSpaceError - screenSpaceError, 0);
  }

  /**
   *  Requests the tile's content.
   * The request may not be made if the Request Scheduler can't prioritize it.
   */
  // eslint-disable-next-line max-statements, complexity
  async loadContent(): Promise<boolean> {
    if (this.hasEmptyContent) {
      return false;
    }

    if (this.content) {
      return true;
    }

    const expired = this.contentExpired;

    if (expired) {
      this._expireDate = null;
    }

    this.contentState = TILE_CONTENT_STATE.LOADING;

    const requestToken = await this.tileset._requestScheduler.scheduleRequest(
      this.id,
      this._getPriority.bind(this)
    );

    if (!requestToken) {
      // cancelled
      this.contentState = TILE_CONTENT_STATE.UNLOADED;
      return false;
    }

    try {
      const contentUrl = this.tileset.getTileUrl(this.contentUrl);
      // The content can be a binary tile ot a JSON tileset
      const loader = this.tileset.loader;
      const options = {
        ...this.tileset.loadOptions,
        [loader.id]: {
          // @ts-expect-error
          ...this.tileset.loadOptions[loader.id],
          isTileset: this.type === 'json',
          ...this._getLoaderSpecificOptions(loader.id)
        }
      };

      this.content = await load(contentUrl, loader, options);

      if (this.tileset.options.contentLoader) {
        await this.tileset.options.contentLoader(this);
      }

      if (this._isTileset()) {
        // Add tile headers for the nested tilset's subtree
        // Async update of the tree should be fine since there would never be edits to the same node
        // TODO - we need to capture the child tileset's URL
        this.tileset._initializeTileHeaders(this.content, this);
      }

      this.contentState = TILE_CONTENT_STATE.READY;
      this._onContentLoaded();
      return true;
    } catch (error) {
      // Tile is unloaded before the content finishes loading
      this.contentState = TILE_CONTENT_STATE.FAILED;
      throw error;
    } finally {
      requestToken.done();
    }
  }

  // Unloads the tile's content.
  unloadContent() {
    if (this.content && this.content.destroy) {
      this.content.destroy();
    }
    this.content = null;
    if (this.header.content && this.header.content.destroy) {
      this.header.content.destroy();
    }
    this.header.content = null;
    this.contentState = TILE_CONTENT_STATE.UNLOADED;
    return true;
  }

  /**
   * Update the tile's visibility
   * @param {Object} frameState - frame state for tile culling
   * @param {string[]} viewportIds - a list of viewport ids that show this tile
   * @return {void}
   */
  updateVisibility(frameState, viewportIds) {
    if (this._frameNumber === frameState.frameNumber) {
      // Return early if visibility has already been checked during the traversal.
      // The visibility may have already been checked if the cullWithChildrenBounds optimization is used.
      return;
    }

    const parent = this.parent;
    const parentVisibilityPlaneMask = parent
      ? parent._visibilityPlaneMask
      : CullingVolume.MASK_INDETERMINATE;

    if (this.tileset._traverser.options.updateTransforms) {
      const parentTransform = parent ? parent.computedTransform : this.tileset.modelMatrix;
      this._updateTransform(parentTransform);
    }

    this._distanceToCamera = this.distanceToTile(frameState);
    this._screenSpaceError = this.getScreenSpaceError(frameState, false);
    this._visibilityPlaneMask = this.visibility(frameState, parentVisibilityPlaneMask); // Use parent's plane mask to speed up visibility test
    this._visible = this._visibilityPlaneMask !== CullingVolume.MASK_OUTSIDE;
    this._inRequestVolume = this.insideViewerRequestVolume(frameState);

    this._frameNumber = frameState.frameNumber;
    this.viewportIds = viewportIds;
  }

  // Determines whether the tile's bounding volume intersects the culling volume.
  // @param {FrameState} frameState The frame state.
  // @param {Number} parentVisibilityPlaneMask The parent's plane mask to speed up the visibility check.
  // @returns {Number} A plane mask as described above in {@link CullingVolume#computeVisibilityWithPlaneMask}.
  visibility(frameState, parentVisibilityPlaneMask) {
    const {cullingVolume} = frameState;
    const {boundingVolume} = this;

    // TODO Cesium specific - restore clippingPlanes
    // const {clippingPlanes, clippingPlanesOriginMatrix} = tileset;
    // if (clippingPlanes && clippingPlanes.enabled) {
    //   const intersection = clippingPlanes.computeIntersectionWithBoundingVolume(
    //     boundingVolume,
    //     clippingPlanesOriginMatrix
    //   );
    //   this._isClipped = intersection !== Intersect.INSIDE;
    //   if (intersection === Intersect.OUTSIDE) {
    //     return CullingVolume.MASK_OUTSIDE;
    //   }
    // }

    // return cullingVolume.computeVisibilityWithPlaneMask(boundingVolume, parentVisibilityPlaneMask);
    return cullingVolume.computeVisibilityWithPlaneMask(boundingVolume, parentVisibilityPlaneMask);
  }

  // Assuming the tile's bounding volume intersects the culling volume, determines
  // whether the tile's content's bounding volume intersects the culling volume.
  // @param {FrameState} frameState The frame state.
  // @returns {Intersect} The result of the intersection: the tile's content is completely outside, completely inside, or intersecting the culling volume.
  contentVisibility() {
    return true;

    // TODO restore
    /*
    // Assumes the tile's bounding volume intersects the culling volume already, so
    // just return Intersect.INSIDE if there is no content bounding volume.
    if (!defined(this.contentBoundingVolume)) {
      return Intersect.INSIDE;
    }

    if (this._visibilityPlaneMask === CullingVolume.MASK_INSIDE) {
      // The tile's bounding volume is completely inside the culling volume so
      // the content bounding volume must also be inside.
      return Intersect.INSIDE;
    }

    // PERFORMANCE_IDEA: is it possible to burn less CPU on this test since we know the
    // tile's (not the content's) bounding volume intersects the culling volume?
    const cullingVolume = frameState.cullingVolume;
    const boundingVolume = tile.contentBoundingVolume;

    const tileset = this.tileset;
    const clippingPlanes = tileset.clippingPlanes;
    if (defined(clippingPlanes) && clippingPlanes.enabled) {
      const intersection = clippingPlanes.computeIntersectionWithBoundingVolume(
        boundingVolume,
        tileset.clippingPlanesOriginMatrix
      );
      this._isClipped = intersection !== Intersect.INSIDE;
      if (intersection === Intersect.OUTSIDE) {
        return Intersect.OUTSIDE;
      }
    }

    return cullingVolume.computeVisibility(boundingVolume);
    */
  }

  /**
   * Computes the (potentially approximate) distance from the closest point of the tile's bounding volume to the camera.
   * @param frameState The frame state.
   * @returns {Number} The distance, in meters, or zero if the camera is inside the bounding volume.
   */
  distanceToTile(frameState: FrameState): number {
    const boundingVolume = this.boundingVolume;
    return Math.sqrt(Math.max(boundingVolume.distanceSquaredTo(frameState.camera.position), 0));
  }

  /**
   * Computes the tile's camera-space z-depth.
   * @param frameState The frame state.
   * @returns The distance, in meters.
   */
  cameraSpaceZDepth({camera}): number {
    const boundingVolume = this.boundingVolume; // Gets the underlying OrientedBoundingBox or BoundingSphere
    scratchVector.subVectors(boundingVolume.center, camera.position);
    return camera.direction.dot(scratchVector);
  }

  /**
   * Checks if the camera is inside the viewer request volume.
   * @param {FrameState} frameState The frame state.
   * @returns {Boolean} Whether the camera is inside the volume.
   */
  insideViewerRequestVolume(frameState: FrameState) {
    const viewerRequestVolume = this._viewerRequestVolume;
    return (
      !viewerRequestVolume || viewerRequestVolume.distanceSquaredTo(frameState.camera.position) <= 0
    );
  }

  // TODO Cesium specific

  // Update whether the tile has expired.
  updateExpiration() {
    if (defined(this._expireDate) && this.contentReady && !this.hasEmptyContent) {
      const now = Date.now();
      // @ts-ignore Date.lessThan - replace with ms compare?
      if (Date.lessThan(this._expireDate, now)) {
        this.contentState = TILE_CONTENT_STATE.EXPIRED;
        this._expiredContent = this.content;
      }
    }
  }

  get extras() {
    return this.header.extras;
  }

  // INTERNAL METHODS

  _initializeLodMetric(header) {
    if ('lodMetricType' in header) {
      this.lodMetricType = header.lodMetricType;
    } else {
      this.lodMetricType = (this.parent && this.parent.lodMetricType) || this.tileset.lodMetricType;
      // eslint-disable-next-line
      console.warn(`3D Tile: Required prop lodMetricType is undefined. Using parent lodMetricType`);
    }

    // This is used to compute screen space error, i.e., the error measured in pixels.
    if ('lodMetricValue' in header) {
      this.lodMetricValue = header.lodMetricValue;
    } else {
      this.lodMetricValue =
        (this.parent && this.parent.lodMetricValue) || this.tileset.lodMetricValue;
      // eslint-disable-next-line
      console.warn(
        '3D Tile: Required prop lodMetricValue is undefined. Using parent lodMetricValue'
      );
    }
  }

  _initializeTransforms(tileHeader) {
    // The local transform of this tile.
    this.transform = tileHeader.transform ? new Matrix4(tileHeader.transform) : new Matrix4();

    const parent = this.parent;
    const tileset = this.tileset;

    const parentTransform =
      parent && parent.computedTransform
        ? parent.computedTransform.clone()
        : tileset.modelMatrix.clone();
    this.computedTransform = new Matrix4(parentTransform).multiplyRight(this.transform);

    const parentInitialTransform =
      parent && parent._initialTransform ? parent._initialTransform.clone() : new Matrix4();
    this._initialTransform = new Matrix4(parentInitialTransform).multiplyRight(this.transform);
  }

  _initializeBoundingVolumes(tileHeader) {
    this._contentBoundingVolume = null;
    this._viewerRequestVolume = null;

    this._updateBoundingVolume(tileHeader);
  }

  _initializeContent(tileHeader) {
    // Empty tile by default
    this.content = {_tileset: this.tileset, _tile: this};
    this.hasEmptyContent = true;
    this.contentState = TILE_CONTENT_STATE.UNLOADED;

    // When `true`, the tile's content points to an external tileset.
    // This is `false` until the tile's content is loaded.
    this.hasTilesetContent = false;

    if (tileHeader.contentUrl) {
      this.content = null;
      this.hasEmptyContent = false;
    }
  }

  // TODO - remove anything not related to basic visibility detection
  _initializeRenderingState(header) {
    this.depth = header.level || (this.parent ? this.parent.depth + 1 : 0);
    this._shouldRefine = false;

    // Members this are updated every frame for tree traversal and rendering optimizations:
    this._distanceToCamera = 0;
    this._centerZDepth = 0;
    this._screenSpaceError = 0;
    this._visibilityPlaneMask = CullingVolume.MASK_INDETERMINATE;
    this._visible = undefined;
    this._inRequestVolume = false;

    this._stackLength = 0;
    this._selectionDepth = 0;

    this._frameNumber = 0;
    this._touchedFrame = 0;
    this._visitedFrame = 0;
    this._selectedFrame = 0;
    this._requestedFrame = 0;

    this._priority = 0.0;
  }

  _getRefine(refine) {
    // Inherit from parent tile if omitted.
    return refine || (this.parent && this.parent.refine) || TILE_REFINEMENT.REPLACE;
  }

  _isTileset() {
    return this.contentUrl.indexOf('.json') !== -1;
  }

  _onContentLoaded() {
    // Vector and Geometry tile rendering do not support the skip LOD optimization.
    switch (this.content && this.content.type) {
      case 'vctr':
      case 'geom':
        // @ts-ignore
        this.tileset._traverser.disableSkipLevelOfDetail = true;
        break;
      default:
    }

    // The content may be tileset json
    if (this._isTileset()) {
      this.hasTilesetContent = true;
    } else {
      this.gpuMemoryUsageInBytes = this._getGpuMemoryUsageInBytes();
    }
  }

  _updateBoundingVolume(header) {
    // Update the bounding volumes
    this.boundingVolume = createBoundingVolume(
      header.boundingVolume,
      this.computedTransform,
      this.boundingVolume
    );

    const content = header.content;
    if (!content) {
      return;
    }

    // TODO Cesium specific
    // Non-leaf tiles may have a content bounding-volume, which is a tight-fit bounding volume
    // around only the features in the tile. This box is useful for culling for rendering,
    // but not for culling for traversing the tree since it does not guarantee spatial coherence, i.e.,
    // since it only bounds features in the tile, not the entire tile, children may be
    // outside of this box.
    if (content.boundingVolume) {
      this._contentBoundingVolume = createBoundingVolume(
        content.boundingVolume,
        this.computedTransform,
        this._contentBoundingVolume
      );
    }
    if (header.viewerRequestVolume) {
      this._viewerRequestVolume = createBoundingVolume(
        header.viewerRequestVolume,
        this.computedTransform,
        this._viewerRequestVolume
      );
    }
  }

  // Update the tile's transform. The transform is applied to the tile's bounding volumes.
  _updateTransform(parentTransform = new Matrix4()) {
    const computedTransform = parentTransform.clone().multiplyRight(this.transform);
    const didTransformChange = !computedTransform.equals(this.computedTransform);

    if (!didTransformChange) {
      return;
    }

    this.computedTransform = computedTransform;

    this._updateBoundingVolume(this.header);
  }

  // Get options which are applicable only for the particular loader
  _getLoaderSpecificOptions(loaderId) {
    switch (loaderId) {
      case 'i3s':
        return {
          ...this.tileset.options.i3s,
          _tileOptions: {
            attributeUrls: this.header.attributeUrls,
            textureUrl: this.header.textureUrl,
            textureFormat: this.header.textureFormat,
            textureLoaderOptions: this.header.textureLoaderOptions,
            materialDefinition: this.header.materialDefinition,
            isDracoGeometry: this.header.isDracoGeometry,
            mbs: this.header.mbs
          },
          _tilesetOptions: {
            store: this.tileset.tileset.store,
            attributeStorageInfo: this.tileset.tileset.attributeStorageInfo,
            fields: this.tileset.tileset.fields
          },
          isTileHeader: false
        };
      case '3d-tiles':
      case 'cesium-ion':
      default:
        return get3dTilesOptions(this.tileset.tileset);
    }
  }
}