Determines whether object is affected by global ambient light.

Legal values: integers

Default value: 0

If flag is 0, the object is not affected by ambient light in the level. Otherwise, the ambient light affects the object.

This effect name is counter-intuitive. I would expect setIllum(1) to make an object self-illuminated, but the truth is almost completely opposite. setIllum(1) and setLighting(1) make an object react to light exactly like a ship.