text: load_manager.set_loader('ptero', ['ground','cactus'], function() {
    let parser = new vox.Parser();
    let frames = [];
    let framesCount = 5; // including 0
  
    for(let i = 0; i <= framesCount; i++) {
      // load all .vox frames
      parser.parse(config.base_path + 'objects/ptero/' + i + '.vox').then(function(voxelData) {
        let builder = new vox.MeshBuilder(voxelData, {voxelSize: .1});
        let material = new THREE.MeshLambertMaterial();
        material.map = vox.MeshBuilder.textureFactory.getTexture(voxelData);
        builder.material = material;
  
        frames[i] = builder;
  
        if(frames.length - 1 == framesCount) {
          load_manager.set_vox('ptero', frames);
          load_manager.set_status('ptero', true);
        }
      });
    }
  });