In article <3c7431cb$1@news.povray.org>, zie### [at] atlantiswh2tu-dresdende 
says...
> 
> 
> I have. The sawtooth-like structures in the upper part of the picture get
> thinner on the right side. So more secondary electrons emerge from the
> sample which brighten up the image in that parts. ("Kante" means "edge", for
> those who don't speak german.)
> 
> BTW, there _can_ be a "directional lighting" in SEM images. It just depends
> on how much voltage you apply to the detector grid. If, for example, the
> voltage is zero, you collect only those electrons flying directly into the
> detector, leaving the surfaces facing away from it completely dark.

True: in that case you collect back-nscattered electrons only.

> 
> In POV you could perhaps simulate SEM images by radiosity. If you put a thin
> horizontal ring around the scene, with ambient=1 all parts facing horizontal
> would be the brightest, and all facing vertical would be the darkest,
> assumed the camera is looking along -y.
> 
> Michael

-- 
Regards, 
Sander

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