I’m slightly embarrassed to be asking this…
I’m making a rocket trail for a commerical animation. The particles are emitted from a plane parented to the rocket mesh. The problem is that they are emitted in bunches every frame, like this :
Whereas in older versions of the particle system, say from 2.45, I get this (with the equivalent settings) :
Now there fortunately isn’t any overriding reason to use 2.49, I can go back to 2.45, but I prefer not to. The particle system does have the nice brownian motion feature, amongst other things.