Suspension geometry

Hi guys,
I'm new in this forum but I have been using Assetto Corsa for a couple of years now.
I'm about to modify the geometry of a double wishbone suspension but I really can't understand which is the reference point of the coordinates. I can't find a clear anwer in any forum, looks like it's about the wheel axle, but where?in the wheel centerline or in the hub?
For example WBCAR_TOP_FRONT = 0.305 , 0.028 , 0.088.

What these values refer to?
thanks to all

cheers

 

wheel centreline. To check just set a value to 0,0,0 and see where it is

 

ok thank you!

 

The content manager application is handy for this, as you can overlay the suspension lines onto the model of the car. Makes it very easy to see the changes immediately.