POV-Ray : Newsgroups : irtc.stills : TC-RTC comments : Re: TC-RTC comments Server Time
19 Jun 2021 06:02:14 EDT (-0400)
  Re: TC-RTC comments  
From: Thomas de Groot
Date: 2 Sep 2008 03:08:23
Message: <48bce667$1@news.povray.org>
"Hildur K." <hil### [at] 3dcafemailevery1net> schreef in bericht 
> Hi Thomas, I like you image very much! Actually my favorite this round. 
> But they

Thank you Hildur!

> to the
> default value. Which is 0.1 and therefore emitting light! So if you want 
> to get
> rid of ambient finish you have to write ambient 0 for every single 
> material.
> (My favorite is diffuse 0.9, ambient 0, looks realistic in most cases, 
> except
> for some metals maybe.)
> If ambient is left to the default you lose the "shadows inside the shadow" 
> if
> you know what I mean.

Yes indeed, that is why I always #default{ambient 0 diffuse 1} at the start 
of my scenes. However, examining my code again, I discovered that in this 
scene I stupidly set this default *only* when no radiosity is used!!! 
Arrrgh!!! That might account for part of the problem. I could indeed also 
the default diffuse a bit. I have made several scenes even with a diffuse of 
0.5, but I must say that was a bit overdone maybe.

> Using a single light source like you did, is the best (only) approach in 
> your
> case, using
> radiosity instead to take care of the shadow areas and should look great 
> in

> potential
> light wise.
> It also seems that you are basing your radiosity settings on the default 
> Pov
> values which I have found fast but useless in most cases, the colors 
> usually are
> way to bright and saturated and everything looks flat and artificial.

Hmm. Yes, I see what you mean. There are several settings that I am not 
really sure of and I mostly leave them alone. Those I always experiment with 
in each scene are error_bound, count, recursion_limit, gray_threshold. To 
tell the truth, I always feel a bit unconfortable with radiosity. I 
certainly lack a deep knowledge of the thing, unfortunately.

> radiosity
> settings there can be used as a base for you settings, even thought the
> situation is somewhat different. They are originally
> based on the Pov manual as the "best" but always have to be tweaked. Maybe 
> you
> should check it out.
> http://www.simnet.is/hildurka/content/tut1page.htm

Shame on me! Of course I know your tutorial! And as it goes, I forgot about 
it in the moment I could use it most. I shall always remain amazed by the 
strange workings of the mind  :-)
Thanks Hildur, for putting me on track again. Lessons are learned the hard 
way, especially by lazy pupils....

> to

> days! ;)

I don't mind having render times of several days (my latest for the new 
TC-RTC round is already in that stage), and I agree that it is worth the 
while. I am going to experiment further with this, especially as I am not 
really happy with the scene in its present state, which is the reason I am 
surprised at even getting a second place at all...

Thanks for your comments Hildur. I do appreciate them very much.


Post a reply to this message

Copyright 2003-2021 Persistence of Vision Raytracer Pty. Ltd.