How to use the Fog particle toolset in Foundry's Nuke

Please, why can't I use Particle Emiter.
If I open this function, the whole dialog will remain dark - inactive
well thank you

You shouldn't Plus that smoke on top of the footage. It's not physically correct :-)

anyone can move the box? it doesn't move the position. my camera tracking set to origin position so that i have to set the position of particle box..

:0

i am in love with nuke the foundry