1. Create new mission in editor.
2. Place the player as any soldier (with NV goggles) in an area that has no artificial lights and has some trees/bushes.
3. Set time to night (I used 2:00am)
4. Place a fireplace (burning) object near the player.
5. Preview mission.
6. Move to the extremities of the area lit by the campfire (between 200m and 250m).
7. Observe vegetation flashing.