cam_pos      = [-0.616586, 0.914186, -0.137893]';
cam_dir      = [0.679765, 0.0812833, -0.728912]';
cam_up       = [0.733063, -0.0438516, 0.678746]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.0308649, 1.32432, 0.118895]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;