function getAccessorData(json, lib, accessorIdx, isIndices) {
    var accessorInfo = json.accessors[accessorIdx];

    var buffer = lib.bufferViews[accessorInfo.bufferView];
    var byteOffset = accessorInfo.byteOffset || 0;
    var ArrayCtor = ARRAY_CTOR_MAP[accessorInfo.componentType] || vendor.Float32Array;

    var size = SIZE_MAP[accessorInfo.type];
    if (size == null && isIndices) {
        size = 1;
    }
    var arr = new ArrayCtor(buffer, byteOffset, size * accessorInfo.count);

    var quantizeExtension = accessorInfo.extensions && accessorInfo.extensions['WEB3D_quantized_attributes'];
    if (quantizeExtension) {
        var decodedArr = new vendor.Float32Array(size * accessorInfo.count);
        var decodeMatrix = quantizeExtension.decodeMatrix;
        var decodeOffset;
        var decodeScale;
        var decodeOffset = new Array(size);
        var decodeScale = new Array(size);
        for (var k = 0; k < size; k++) {
            decodeOffset[k] = decodeMatrix[size * (size + 1) + k];
            decodeScale[k] = decodeMatrix[k * (size + 1) + k];
        }
        for (var i = 0; i < accessorInfo.count; i++) {
            for (var k = 0; k < size; k++) {
                decodedArr[i * size + k] = arr[i * size + k] * decodeScale[k] + decodeOffset[k];
            }
        }

        arr = decodedArr;
    }
    return arr;
}
glTF Loader
Specification https://github.com/KhronosGroup/glTF/blob/master/specification/README.md

TODO Morph targets