@loaders.gl/3d-tiles/src/lib/parsers/parse-3d-tile-gltf.ts

3D Tiles, an open standard for streaming massive heterogeneous 3D geospatial datasets.

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

import {parseFromContext, LoaderContext} from '@loaders.gl/loader-utils';
import {_getMemoryUsageGLTF, GLTFLoader, postProcessGLTF} from '@loaders.gl/gltf';
import type {Tiles3DLoaderOptions} from '../../tiles-3d-loader';
import {Tiles3DTileContent} from '../../types';

export async function parseGltf3DTile(
  tile: Tiles3DTileContent,
  arrayBuffer: ArrayBuffer,
  options?: Tiles3DLoaderOptions,
  context?: LoaderContext
): Promise<number> {
  // Set flags
  // glTF models need to be rotated from Y to Z up
  // https://github.com/AnalyticalGraphicsInc/3d-tiles/tree/master/specification#y-up-to-z-up
  tile.rotateYtoZ = true;
  // Save gltf up axis
  tile.gltfUpAxis = options?.['3d-tiles']?.assetGltfUpAxis
    ? options['3d-tiles'].assetGltfUpAxis
    : 'Y';

  if (options?.['3d-tiles']?.loadGLTF) {
    if (!context) {
      return arrayBuffer.byteLength;
    }
    const gltfWithBuffers = await parseFromContext(arrayBuffer, GLTFLoader, options, context);
    tile.gltf = postProcessGLTF(gltfWithBuffers);
    tile.gpuMemoryUsageInBytes = _getMemoryUsageGLTF(tile.gltf);
  } else {
    tile.gltfArrayBuffer = arrayBuffer;
  }
  return arrayBuffer.byteLength;
}