fumefx and particleflow move on a spline

[Rif]

hehe.. or u just simply use some particle path follow operator in tp and get some real voxel based rigid body right away without going outside and 2 stepping..

For killing smoke u could either use the script like kreso is saying following the emitor or just born a certain amount of particle offset - X frames from the rule based path follow method dumping into a "deleteFFx" Group .. this group can be used in negative values to kill behind and colder the solution etc.. as mentionned below..

but ya.. not everyone has it..