cam_pos      = [-0.827738, 1.29242, -0.269639]';
cam_dir      = [-0.00783176, 0.156455, 0.987654]';
cam_up       = [0.467053, 0.873904, -0.134732]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [1.17598, -0.612107, 0.106289]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;