Here's a tutorial in the making, using the new Animated Swap feature
of PD Pro 4.1, to simulate the distortion effect of hot air rising
(can also be used for underwater effects)
http://thebest3d.com/pdpro/tutorials/animswap/index.htmlIn a nutshell, the displacement map DWA was created byvertically
flipping an animation containing snowfall. Lots of snowfall, to the
point where you don't see or recognize a few distinct snow flakes.
Instead, it's a whole 'wall' of particles moving like through rush
hour. Large flakes, lots of them. And not too much contrast either
unless you want it crazy distorted.
I also used an alpha channel with progressive transition (linear alpha
fader) so the amount of distortion is stronger up high and down low.
As a result and side effect, when the camera moves sideways fast and
you see the edge of the sand dune go from high to low along the slope,
you see a ghost image, like double-vision. Not intended, but actually
a neat effect when you want to convey the looks and feels of
fata-morganas and you're about to collapse from this desert heat.
Welcome to Death Valley ;-)
-Philip