If mappers want to add effects like smoke to a map, they have to manually add those using envelopes. It would be easier if mappers were able to add effect sources on the game layer. For example a smoke source could be added on a campfire or chimney to constantly emit some smoke particles, which are simulated by the games engine like other smoke particles. In particular this would make air flow simulation #2437 more relevant. Right now the only source of smoke are grenade explosions and ...