As I know, normal maps alter the surface of the geometry, in opposition with bump maps who only alter the perception, the reflection of light on surface.Chris wrote:Nice results.
I would be very surprised that light emitting materials change their emission direction based on a normal map. You might be able to use an IES emitting texture though...
So, if normal mapping will alter the surface, the resulted indentations would limit the spread angle of light, thus creating a spot-like effect.
I don't know how a IES texture works, even though I'm using IES in Twilight pretty often. I don't know how and if it can be applied to a linear shape. I'm only using IES for Twilight Lights (I set a light, then I load a IES on it).