cam_pos      = [-0.638656, 1.82003, 0.146348]';
cam_dir      = [0.888652, -0.150221, 0.433281]';
cam_up       = [0.0485299, 0.970325, 0.236883]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [0.606491, 0.252007, -1.15653]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;