GLTFParser.prototype.loadTexture = function(textureIndex) {
      var parser = this;
      var json = this.json;
      var options = this.options;
      var textureLoader = this.textureLoader;
      var URL = global.URL;
      var textureDef = json.textures[textureIndex];
      var textureExtensions = textureDef.extensions || {};
      var source;
      if (textureExtensions[EXTENSIONS.MSFT_TEXTURE_DDS]) {
        source = json.images[textureExtensions[EXTENSIONS.MSFT_TEXTURE_DDS].source]
      } else {
        source = json.images[textureDef.source]
      }
      var sourceURI = source.uri;
      var isObjectURL = false;
      if (source.bufferView !== undefined) {
        sourceURI = parser.getDependency('bufferView', source.bufferView).then(function(bufferView) {
          isObjectURL = false;
		  var base64 = ArrayBufferToBase64(bufferView);
		  var sourceURI = `data:${source.mimeType};base64,${base64}`;
          return sourceURI
        })

      }

gltf-loader的这里改一下。然后自己定义个ArrayBufferToBase64的接口
import { encode as ArrayBufferToBase64 } from '../../three-platformize/src/libs/base64-arraybuffer';
export function encode(arrayBuffer) {
  var base64 = '';


  var bytes = new Uint8Array(arrayBuffer);
  var byteLength = bytes.byteLength;
  var byteRemainder = byteLength % 3;
  var mainLength = byteLength - byteRemainder;


  var a, b, c, d;
  var chunk;


  // Main loop deals with bytes in chunks of 3
  for (var i = 0; i < mainLength; i = i + 3) {
    // Combine the three bytes into a single integer
    chunk = (bytes[i] << 16) | (bytes[i + 1] << 8) | bytes[i + 2];


    // Use bitmasks to extract 6-bit segments from the triplet
    a = (chunk & 16515072) >> 18; // 16515072 = (2^6 - 1) << 18
    b = (chunk & 258048) >> 12; // 258048   = (2^6 - 1) << 12
    c = (chunk & 4032) >> 6; // 4032     = (2^6 - 1) << 6
    d = chunk & 63; // 63       = 2^6 - 1


    // Convert the raw binary segments to the appropriate ASCII encoding
    base64 += chars[a] + chars[b] + chars[c] + chars[d];
  }


  // Deal with the remaining bytes and padding
  if (byteRemainder == 1) {
    chunk = bytes[mainLength];


    a = (chunk & 252) >> 2; // 252 = (2^6 - 1) << 2


    // Set the 4 least significant bits to zero
    b = (chunk & 3) << 4; // 3   = 2^2 - 1


    base64 += chars[a] + chars[b] + '==';
  } else if (byteRemainder == 2) {
    chunk = (bytes[mainLength] << 8) | bytes[mainLength + 1];


    a = (chunk & 64512) >> 10; // 64512 = (2^6 - 1) << 10
    b = (chunk & 1008) >> 4; // 1008  = (2^6 - 1) << 4


    // Set the 2 least significant bits to zero
    c = (chunk & 15) << 2; // 15    = 2^4 - 1


    base64 += chars[a] + chars[b] + chars[c] + '=';
  }


  return base64;
}