Compare depths with a tolerance in the dual depth peeler.
Compare depths with a tolerance in the dual depth peeler.

Similar to the older depth peeler, sometimes the GL implementation
computes slightly different depths for the same fragments from one
pass to the next. Use a small tolerance when identifying the currently
peeled fragments.

keithroe/vtkoptix,keithroe/vtkoptix,keithroe/vtkoptix,keithroe/vtkoptix,keithroe/vtkoptix,keithroe/vtkoptix,keithroe/vtkoptix,keithroe/vtkoptix