def load_voxel_params(param):
    """
    Based on the lidar range and resolution of voxel, calcuate the anchor box
    and target resolution.

    Parameters
    ----------
    param : dict
        Original loaded parameter dictionary.

    Returns
    -------
    param : dict
        Modified parameter dictionary with new attribute `anchor_args[W][H][L]`
    """
    anchor_args = param['postprocess']['anchor_args']
    cav_lidar_range = anchor_args['cav_lidar_range']
    voxel_size = param['preprocess']['args']['voxel_size']

    vw = voxel_size[0]
    vh = voxel_size[1]
    vd = voxel_size[2]

    anchor_args['vw'] = vw
    anchor_args['vh'] = vh
    anchor_args['vd'] = vd

    anchor_args['W'] = int((cav_lidar_range[3] - cav_lidar_range[0]) / vw)
    anchor_args['H'] = int((cav_lidar_range[4] - cav_lidar_range[1]) / vh)
    anchor_args['D'] = int((cav_lidar_range[5] - cav_lidar_range[2]) / vd)

    param['postprocess'].update({'anchor_args': anchor_args})

    # sometimes we just want to visualize the data without implementing model
    if 'model' in param:
        param['model']['args']['W'] = anchor_args['W']
        param['model']['args']['H'] = anchor_args['H']
        param['model']['args']['D'] = anchor_args['D']

    return param