How it works

Archicad2Blender is two programs that talk over a TCP socket on the same machine.

The Blender add-on is the server. It opens a port and waits. The Archicad add-on is the client. It connects out, reads the 3D model, sends it once in full, then sends the elements that change.

Archicad's API can only be used on its main thread. A background thread moves bytes and never calls it. Both applications must be running. Nothing is written to disk except a texture cache.

The connection carries a source_name of the form a2b:<project key>. Everything the add-on builds is namespaced by it, so several projects can share one Blender scene.