cam_pos      = [0.189744, 1.6882, 0.839917]';
cam_dir      = [-0.946168, -0.25266, 0.202308]';
cam_up       = [-0.29497, 0.415741, -0.860321]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.177237, 1.162, 0.622292]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;