"Thomas White" <her### [at] removebtinternetcom> wrote in message
news:39f5fce1@news.povray.org...
> Almost the very first image I rendered consisted of a simple sphere lit from
> three different directions with red, green and blue light sources.  When the
> sphere is smooth, the different colours of illumination blend together very
> smoothly.  The trouble is, when I add a bumpy texture with "normal { bumps
> 0.8 scale 0.2 }" I can see a definite sharp edge to the illumination that
> should not be there.  What is going on?  The sharp edges do not follow the
> contours created by the texture - they are just circular lines going around
> the sphere.

Common misconception about what a texture normal is versus a surface
displacement (of which only MegaPOV is currently capable of in any way
whatsoever).
The texture doesn't perturb or affect the physical surface at all, much the
same thing would be seen if you painted a ball in such a way so as to make it
appear to deform from a perfect sphere with shading and the like.  Lights shone
upon it would show the same thing as in a POV-Ray render, it's all a trick of
illumination and shading.  POV-Ray won't flex the surface to fit a texture,
quite the opposite could be said (not empirically however).

Note to Warp:  this doesn't seem to be in your VFAQ.  Might make a good
inclusion.

Bob

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