How to create a portal in AR using a mask?

Hello

I would like to know which would be the most ideal way to create a portal in AR.

I guess that one way would be to use a Shader applied to a plane that would allow us just to see the 3d world through a hole and anything that is not behind the hole would not be rendered?

If the Shader is the best solution, which one would you recommend me? And how should I use it?

Thanks

https://github.com/playcanvas/engine/tree/master/examples/portal

Thanks @Glen_Ko but I couldn’t get it to work. I believe it has not been updated? Also the debugging console is giving me lots of warnings.