I find PovRAY, especialy with camera_view added in MegaPOV, very usefull 
for pre-rendering objects for later using them to create real-time lighting 
effects.

One of problems I came across is to pre-render with parts of sky can be 
seen / are reflected by given parts of object.

camera_view output 3 does something like that (lets call it image A), only 
it dont take into account that one part of object blocks/shadows other 
parts of object.

I think that object { MyObject pigment { rgb 1 } finish { reflection 1 } }
with global_settings { max_trace_level 1 }  and special sky_sphere might 
give such result (lets call it image B).


A and B can be used to dynamicly add light to the object not using povray 
(just go throught each pixel of rendered image, if color indicates that 
normal of object is close to direction of our light that we can _add_ or 
move in _real time_ - then light the object - giving specular highlight 
effect).

Image A (output 3) can be used for ambient/shadowless light, and Image B 
for normal lights.

Ofcourse results will not be perfect, but combined with few other tricks I 
hope to achive good effect.

Now, the questions,
  what sky_sphere {...} use so it will match effects of using camera_view 
output 3 (so, green at top, blue at +z end, and so on). I quess it will be 
combination of 3 gradients? Or some function{} ?

<lame>how to apply other texture to object that already have a 
texture/material?  object { MyObjet texture{...} } changes only this parts 
of MyObject that didnt had texture assigned.</lame>

By any chance someone have formula, when normal of surface is <x,y,z> and 
light is in <X,Y,Z> with rgb 1.0, how to calculate specular or phong color 
in taht point?

-- 
http://www.raf256.com/3d/
Rafal Maj 'Raf256', home page - http://www.raf256.com/me/
Computer Graphics

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