I'm using Farseer for physics in a game, and have several key classes: Planet and PlanetProp. Each planet has a large circular body and a "field". This field is a large sensor around the body. PlanetProps are pulled towards whichever planet's field they are currently in (a struct called PlanetInfo). So I've set up a collision handler in PlanetProp which will (whenever it is called) detect whether the fixture it has collided with is a sensor.
I then plan to A) detect if the sensor belongs to a Planet and B) Set the PlanetProp to be pulled towards the planet
So in other words, is it possible to access a class using a collision callback with a fixture from a body in that class?
EDIT: Does this involve UserData? If I was using C++ I might be able to put a pointer to the class in that, but I'm using c#.