From TDN

In the console, type in "myScenegraph.setdebugon(#)". If you don't know the scenegraph name, you can type the following into the console:

sceneWindow2d.getScenegraph().setdebugon(#)

where sceneWindow2d is the name of your t2dWindowScene. 'sceneWindow2d' is the default name, so if you haven't changed it, use that. This will get the scenegraph name and set the debug mode on. # is the number which represents different types of data. Below is a list of numbers you can input:

0 - This will show the debug banner with an array of information including Frames Per Second.
1 - Bounding, collision and clipping boxes. 
2 - Mount nodes. 
3 - Mount force lines. 
4 - World limit. 
5 - Collision Bounds.

To turn any of the information off, simply type:

sceneWindow2d.getScenegraph().setDebugOff(#)