cam_pos      = [0.626437, 1.34436, -0.301319]';
cam_dir      = [-0.925804, -0.323729, -0.195159]';
cam_up       = [-0.294958, 0.941567, -0.162637]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.31442, 0.123699, 1.28637]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;