Seems like everybody is working these days on a lighting system for Poser.
 @vopehov506, your approach looks very promising, the light setup does give the texture the extra Umpf, so to speak.
I'm also working on something on the subject matter. Here is a Testrender.
Let me know what you folks think about it.

This is obviously an old familiar face, V4 in a texture from Syltermermaid, enhanced with Snarlygribbly's EZSkin 3. The scene is lit by a one lightsource.
My setup is quite mechanical, I use one sphere for the light source and one for the sky. To simulate differend day times I created a circle with a texture gradient with colors from sun set to star light.
I also created another circle with a gray scale to influence the intensity of the light. 
The light source can be morphed in size and is contained in a cylinder.
The opening of the cylinder is also morhpable to be open or closed. 
The whole thing looks like this.

This is Sun Down....
 

This is Star Light, or night scene lighting, if you will.
The whole thing is in the test phase and much work to be done.
I want to add an realistic looking sky and the whole system is meant to be managed from a single parameter palette.