cam_pos      = [0.205114, 0.688341, -0.343558]';
cam_dir      = [0.881283, 0.248042, 0.402263]';
cam_up       = [-0.436475, 0.100856, 0.894046]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.240984, 1.28144, -0.262204]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;