Does anyone know how to get the Geometry of an object that is connected as an input port
to my custom operator (C++), from inside the operators Update() function?

The GetGeometry(time) doesn’t work because, as it says in the docs, inside the update() function the ‘time’ is ignored.
I tried using the Primitive.EvalAt(time) but that doesn’t work either. 

Does anyone have any ideas?

Thanks.