When you have defined your documents in CAM, select one of the Gerber outputs, Edit - Device Setup. Click "Regenerate". This will allocate flashes for most SMD pads. The ones in non-90 degree angle will still be drawn (haven't tried what it does for pads with chamfered or rounded corners - I suppose it will still draw those). But the trick should do the job, at least most of it.
I made a macro that will go through each of the gerber files and augment each gerber file so that most pads are flashed and not drawn.
Here are some other ideas which ask for some of the same things.