Add a "Reset Eye Position" button to tweakbar.
Add handlers for Q and E buttons to control avatar viewpoint height.
Add an FBO gutter size to cull out some of the pixels drawn to the distortion buffer. Note that this is contingent on driver implementation, but I would imagine modern ones perform the scissor test earlier in the pipeline than pixel shader execution.
Update GetPixelCount function to take FBO gutter width into account.
Report distortion FBO size as MegaPixels in float format.