This is a simple Node Group that allows you to drag a Node group in from the asset library and hook it up to a Ray Portal BSDF for a portal with minimal setup.

There is also a material version which you can apply to most objects (works best on objects like a plane or a circle (with fill type set to Ngon).

In the Documentation tab there is a short how-to guide to setup the node group and how to install and set it up in Blender.

As this is only the lite version, you will have to set up the drivers to prevent the portal rotation from breaking when the portal object is moved. The non-lite version is coming soon and will come with a Geometry Nodes node group that fixes that will be fully drag and drop.