Zeger Knaepen nous apporta ses lumieres en ce 2007/08/18 19:23:
> "Warp" <war### [at] tagpovrayorg> wrote in message news:46c6d0fd@news.povray.org...
>> Christian Froeschlin <chr### [at] chrfrde> wrote:
>>>> Every time a ray is reflected or refracted
>>> or when just passing through a transparent surface as in your case.
>>  That's, technically speaking, refraction. The refraction just doesn't
>> modify the direction of the ray.
>>
>>  (One cool developement idea for povray would be, I think, that if a
>> surface has transparency, no reflection and no ior, iow. rays just pass
>> through unmodified (just taking the color of the surface), povray could
>> skip incrementing the recursion counter. That way you could have and
>> indefinite amount of transparent surfaces even if max_trace_level is
>> small.)
> 
> although probably a bit more complicated, couldn't this idea be expanded to 
> objects that do have reflections and/or an ior?
> I might be mistaken, but I believe the only way to get in an infinite loop, is 
> if the ray hits the same object more than once.
> So: if a ray is reflected or refracted, the recursion counter doesn't increment 
> until the same object gets hit again.
> 
> there are probably some cases I'm overseeing...
> 
> cu!
You can have extremely long paths, even infinite ones, between several objects. 
This is very probable with reflections, think of a mirror-hall kind of setting. 
In that case, you need to have less than perfect reflections and probably 
increase the adc_bailout value, or be plagued with chains many 1000's of 
reflections long!
Thank Warp for the reminder of that possibility :-)

-- 
Alain
-------------------------------------------------
WARNING: The consumption of alcohol may create the illusion that you are 
tougher, smarter, faster and better looking than most people.

Post a reply to this message