$G/src/tbvr is the location of the code and various run scripts. i think some of the run scripts specify a dataset to load in the name, if not edit glueconfig file.
important controls:
A - put in alpha mode, now you can draw with mouse in transfer
function boxes to do culling etc..
T - (I think) hides the volume's bounding box
UP/Down arrows - zoom in and out.
right click and drag - trackball rotate the volume
L - load a new pre-saved transfer function, click on the shell window to type in the name of the transfer function to load, first do "ls" in the window to see the available transfer functions.
This should work on spinnaker in dfk's office, or I think it's also setup in the user study room.