Hi ,
on the Apache tutorial animation disc, he runs through what he did to create smoke and heat distortion.

In his expressions he refers to some constant attributes called spriteTwistMultPP and spriteScaleMultPP.

I cant find these in the general list of perparticle attributes to add...so did he create these...and how do you do that properly?

It's my first experience with expressions so would appreciate any help.

Thanks