Q:

Refractive blur in XNA? 

I'm writing a 2D hack-and-slash game using XNA.  I really want to implement the blur-like, refractive effect of a sword or such moving really quickly, seen in such games as Dust: An Elysian Tail and Vampire Dishwasher.  Anyone know the technical name for this effect?  For those who aren't sure what I'm talking about:

shows exactly the effect I'm trying to achieve. 

A:

The XNA education catalog calls it distortion.   Kind of a catch-all term, but it fits. 
http://xbox.create.msdn.com/en-US/education/catalog/sample/distortion

