C# Portal Based Occlusion Culling usage

    Occlusion.ConvexPolygon CreatePolygonFor(VoxelDungeon.Corridor corridor, VoxelDungeon.Corridor.PositionNode pathNode)
    {

        Vector3 pos = new Vector3(pathNode.position.x, mapData.config.groundPlaneHeight, pathNode.position.y) - Vector3.one;
        float h = corridor.height+2;

        int width = corridor.width;
        int wStart = width / 2;
        int wEnd = width - wStart;

        Quaternion rot;
        if(MapData.IsHorizontalFromTop(pathNode.direction)) rot=Quaternion.LookRotation(new Vector3(1,0,0), Vector3.up);
        else rot=Quaternion.LookRotation(new Vector3(0,0,1), Vector3.up);

        var polygon = new Occlusion.ConvexPolygon();
        polygon.points.Add(rot * new Vector3(-wStart, h, 0) + pos);
        polygon.points.Add(rot * new Vector3(wEnd, h, 0) + pos);
        polygon.points.Add(rot * new Vector3(wEnd, 0, 0) + pos);
        polygon.points.Add(rot * new Vector3(-wStart, 0, 0) + pos);
        return polygon;
    }


    void Update()
    {
        if (!isGenerated) return;

        Camera cam = manager.camera.current;
        Vector3 poi = cam.transform.position;// manager.actor.player.position;

        Int3 poii = WorldToLocal(poi);

        VoxelDungeon.OwnerNode owner = null;
        for (int i = 0; i < 8 && owner == null; i++)
        {
            owner = mapData.GetOwnerAt(
                poii.x + tilesOffsets[i, 0],
                poii.y + tilesOffsets[i, 1],
                poii.z + tilesOffsets[i, 2]
            );

        }
        if (owner == null) return;

        NodeData node;
        if (!voxelMapNodeToContainer.TryGetValue(owner, out node)) return;

        node.occlusionArea.StartPropagate(cam);

    }