POV-Ray : Newsgroups : povray.general : materials : Re: materials Server Time
4 Aug 2024 08:18:58 EDT (-0400)
  Re: materials  
From: Anto Matkovic
Date: 11 Jun 2003 11:12:16
Message: <3ee746d0@news.povray.org>
> Hello,
>
> I want to translate some material from Anim8or to PovRay (for a
converter).
>
> In anim8or, my materials have these properties:
>
> Ambient: percentage, color, texture (it can be an image like .gif)
> Diffuse:   percentage, color, texture (it can be an image like .gif)
> Specular: percentage, color, texture (it can be an image like .gif)
> Emissive: percentage, color, texture (it can be an image like .gif)
> Transparancy: percentage, texture (it can be an image like .gif)
> Bumpmap: percentage, texture (it can be an image like .gif)
> Rough: percentage
> Brillance: percentage
>
>
- POV-Ray have a default global ambient set to 1 (rgb 255), in dinstinction
to many scanlines, where this is usually zero or dark grey. If you find on
IRTC site some images with a dark, well saturated colors like an old
painting, this can be work of Jaime Vives Piqueres. He was used a global
ambient color
set to zero.
- POV values can go over 1 or lower to zero (something like rgb 788 or
rgb -200; not too much usable, but you may know that)
- POV ambient color (in materials) working  something like the ambient and
emission (self illumination) together - ambient 1 (both global and 'local')
and diffuse 0 will do 'flat' , intact, pigment colors.
- diffuse is a simple value, not a color or image
- pigment is something like diffuse color, also transparency can be inside
(in POV: filter or transmit)
- transparency or filter color depend on pigment color
- bumpmap is near the same
- POV specular and roughness come with POV specular highlight - it can be
also phong,  or both of them on the same material.
- Brilliance is a something similar (I suppose)
- POV materials haven't independent  highlights color, this depend on the
light color. In case of metallic finish, this do not depend (more precisely,
'near to do not depend').
- POV-Ray distribution sample scenes, and code from 'insert menu' can have a
different 'assumed gamma' value - you need to pay attention to that.

As a pretty old POV home user, and Max user at work, I can say, that's hard
to say what is more realistic, or 'better'. POV materials controls are
surely simplier and easier to figure out, 'more logic', usually they are
easier for tweaking, and don't tend to loose saturation like a many
scanlines (better color clamping, I suppose). Also,
antialiasing-oversampling things are much easier to setup in raytracers than
in scanlines. Even some good scanline renderers tricks (bitmap environment
reflection, as example) are near to impossible in POV.
Roughly, POV is a typicaly raytracer (what a surprise:), and a very fast
raytracer.


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