smoke dissipation

[Rif]

hehe.. well for me this looks like a specific method of choice to emit in order to get this result.. maybe FM would help as well ( Texture Mapping Opacity Curve on the Shader that Deforms with the Flow in worldSpace) ..

showing what You did so far and explaining your source ( are you using a Map for emition ? )

"the animation of Dissipation is not natural" : can you show what is it you get ? have you been able to tweak your dissipation on a simple scene first with replicated smoke density sources ? it might take time ( lots of tries) in order to get your dissipating setup to be settle enough but yet do what you want it to do.. You should easily tweak it on lower voxel amount sim to get the numbers perfectly through all your effect length and then uprezing your voxels amount as tweaking low rez and uprezing after should not need much different tweaks on the fluid at high rez only ( not like ALL the parameters in Fluids Land )

AFC Rendering Shader Opacity Cutter ( cause thats basically what it is , a Curve to Control Opacity Level of where the Voxels Density in the Grid are tagged " Smoke Density" ) is not working well in animation ? again if you can show what does it do it would surely be easier to understand whats not working for ya ..