cam_pos      = [-0.497001, 0.924336, -0.217798]';
cam_dir      = [0.865983, 0.0666575, -0.495611]';
cam_up       = [0.49919, -0.0563518, 0.864658]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.0395108, 1.32492, 0.109159]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;