I will rewrite the heathaze/stealthfield/distortion for the new system, but after 1.9 is official. I want it to be universal and useable for all sorts of distortion, be it a explosion shockwave, refracting glass, water, bullet trails, force fields, predator camo or any ‘magic’ effects…and because it will do all of that it will most likely be suitable only for my dubious purposes.
As for what to include as part of the sdk - there are already some very specific things in the ‘old’ common filters (and some more stuff in the direct dir - a demo or two for mirrors and shadows, parts of a level editor iirc). If that stays then all the new fillters should ship with the sdk. The logical alternative would be not to include any filters at all and ship them only in the samples.