cam_pos      = [-0.749501, 1.24482, 0.273517]';
cam_dir      = [0.982766, -0.118153, 0.142162]';
cam_up       = [0.094253, 0.981868, 0.164471]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [0.211493, 0.197157, -1.29819]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;