849 prep fill area cleanup

@doutriaux1 @aashish24 

Had an hour to kill and took a stab at optimizing the vcs scalar bar implementation. Ended up cutting the time down from 0.262s to 0.89s on my machine.

Ref #849 
Forget my comment about lines gone, I didn't see the upper bit of the code. And yes let's not approve the array padding. Running ctest on your branch and approving.