Ok, I found them. (I'm at work on a Sunday and not very motivated, so I took the time to search around for them

)
The first was a post about a Blur Studio in-house impact system.
http://forums.cgsociety.org/showthread. ... 3&t=438007Right after that posted, if I remember correctly, everyone started discussing making their own versions of the tool.
JHaywood and mir-vadim both decided to start work on them at just about the same time.
JHaywood's Winchester FX tool.
http://forums.cgsociety.org/showthread. ... 3&t=451701Mir-vadim's Rayfire tool.
http://forums.cgsociety.org/showthread. ... ge=1&pp=15I also remember them discussing it in detail in the Particle Flow thread
http://forums.cgsociety.org/forumdisplay.php?f=206But there are just about 300 pages of posts, and I can't even begin to remember where in that long conversation they were talking about it.