Christoph Hormann <chr### [at] gmxde> wrote:



> "news.povray.org" wrote:
>> [...]
>> the obvious thing is that the crackles aren't lit by the environment
>> by radiosity, but only by the sunlight ...
>> 

> - use 'normal on' in the radiosity block. 

I can't find information on this in the POV manual or the MegaPOV manual
(07)  When was this feature added?

On the other hand, it did help me find the "media on" feature, which might
help in my curren WIP scene (although probably will slow it down immensely)


Geoff

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Geoff Wedig wrote:
> 
> I can't find information on this in the POV manual or the MegaPOV manual
> (07)  When was this feature added?
> 
> On the other hand, it did help me find the "media on" feature, which might
> help in my curren WIP scene (although probably will slow it down immensely)
> 

it's mentioned in:

10.2.7. Miscellaneous changes & bug fixes

Never have seen a good example for 'media on' though.

Christoph

-- 
Christoph Hormann <chr### [at] gmxde>
IsoWood include, radiosity tutorial, TransSkin and other 
things on: http://www.schunter.etc.tu-bs.de/~chris/

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From: "Christoph Hormann" <chr### [at] gmxde>

>
>
> "news.povray.org" wrote:
> > [...]
> > the obvious thing is that the crackles aren't lit by the
environment
> > by radiosity, but only by the sunlight ...
> >
>
> - use 'normal on' in the radiosity block.
Where is this described ?? I've never read this ...

> - it's always better to use real surface distortion (isosurface)
instead
> of normal.  Of course it's much slower.
It's obvios that this will work, but not necessary to give the thing a
little structure ...

> > the second thing, (I'm not sure about this) is that there is this
edge
> > on the sphere, that makes it seem, to be a mirror...
> > In the lower half the sphere is brighter, than the upper half.
It's
> > from the radiosity, reflecting the groundfog-brightness ...
> > But I didn't expect such a sharp edge ... Maybe I'm wrong ...
> >
> > except these things it looks quite beautiful .. (I'think)
> > Because it's short, I've attached the source here ...
> >
>
> Some things that should be changed:
>
> - use finish { ambient 0 } for the sphere
It already has this from GroundTex ...
That's what I learned first: In Radiosity pics objects don't need
Ambient, or they will glow...

> - recursion_limit 3 is really unnecessary for such a simple scene.
1 or
> maybe 2 is perfectly sufficient.  This also avoids the sharp
blue/white
> boundary.
I'd preferred to go even deeper ...

--
background{rgb 1}camera{location<1,5,-2>look_at 0}#macro
m(a,b,i)#local d=(b-a)
/8;#local
e=vcross(d,y);#if(i)m(a-e,a+e+2*d,i-1)m(a+e,a+2*d-e,i-1)m(a+3*d-e,a+e
+3*d,i-1)m(a+3*d-e,a+5*d-e,i-1)m(a+6*d-e,a+e+6*d,i-1)m(a+8*d-e,a+e+8*d
,i-1)#else
cylinder{a,b,vlength(d)/3 pigment{rgb 0}}#end#end m(-4*x,2*x,4) // Jan
Walzer

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"Tony[B]" <ben### [at] catholicorg>
> > First: I've not that much experience
> > with radiosity; maybe I'm just
> > using the wrong parameters...
>
> You're not using the ones I use, at least. No one is quite sure
which ones
> are the "right" ones. It's mostly a guessing game. I've been using
mine
> quite happily for some time now. They were developed in conjunction
with
> Gilles and Xplo et al. Even then they need to be adjusted a bit on a
> per-scene basis.
I used the guide in the radiosity chapter of the old docs ...
Of course, I know, Nathan has changed(rewritten?) the radiosity part,
but I hoped, the params still have the same function...

> > I wanted to try something simple, when
> > I saw the radiosity pic of Tony[B]...
>
> I inspired someone... <rapture> :)
No ... not inspired ;)...
I just felt I also need some testing in Radiosity, cause everyone else
is doing this ...

> > the obvious thing is that the crackles
> > aren't lit by the environment
> > by radiosity, but only by the sunlight ...
>
> One thing I wish could be added.
Christoph told me something about the "normal on" parameter in the
radio-statement...
I'm rendering now ...

> > the second thing, (I'm not sure about this)
> > is that there is this edge on the sphere,
> > that makes it seem, to be a mirror...
> I noticed this when I used count 1 or 2. I don't see why you're
getting it
> here.

> > In the lower half the sphere is brighter, than the upper half.
It's
> > from the radiosity, reflecting the groundfog-brightness ...
> > But I didn't expect such a sharp edge ... Maybe I'm wrong ...
>
> In this unrealistic situation, I think it's correct.
>
> > except these things it looks quite beautiful .. (I'think)
> Do radiosity ever look otherwise? :) I'll try your source with my
parameters
Of course not ...
> later. I'm rendering a tabasco bottle for someone.
I hope it will be bigger than the last Image ... ;)


--
background{rgb 1}camera{location<1,5,-2>look_at 0}#macro
m(a,b,i)#local d=(b-a)
/8;#local
e=vcross(d,y);#if(i)m(a-e,a+e+2*d,i-1)m(a+e,a+2*d-e,i-1)m(a+3*d-e,a+e
+3*d,i-1)m(a+3*d-e,a+5*d-e,i-1)m(a+6*d-e,a+e+6*d,i-1)m(a+8*d-e,a+e+8*d
,i-1)#else
cylinder{a,b,vlength(d)/3 pigment{rgb 0}}#end#end m(-4*x,2*x,4) // Jan
Walzer

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Christoph Hormann <chr### [at] gmxde> wrote:



> Geoff Wedig wrote:
>> 
>> I can't find information on this in the POV manual or the MegaPOV manual
>> (07)  When was this feature added?
>> 
>> On the other hand, it did help me find the "media on" feature, which might
>> help in my curren WIP scene (although probably will slow it down immensely)
>> 

> it's mentioned in:

> 10.2.7. Miscellaneous changes & bug fixes

Don't know how I missed it, since I read pretty carefully.  Must be going
blind or stupid, and last I checked, my eyes were fine... *sigh*

> Never have seen a good example for 'media on' though.

Well, I'll do a test render, and if it works, great.  If it doesn't I kill
it.

Geoff

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I think a sphere on a plane always ends up with a sharp line because of the
underlying geometry.  Your sphere has a brighter than average division line
because of the cumulative effect of all that fog (looking at your horizon I
can see a whiter-than-white stripe that gets reflected in your sphere).

I know nothing about radiosity and look forward to seeing your experiment
evolve.

BTW, unless you are the news administrator it would be nice if you changed
your name to something other than "news.povray.org".

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"news.povray.org" wrote:
> 
> >
> > - use finish { ambient 0 } for the sphere
> It already has this from GroundTex ...

Oops, i missed that, sorry.

Christoph

-- 
Christoph Hormann <chr### [at] gmxde>
IsoWood include, radiosity tutorial, TransSkin and other 
things on: http://www.schunter.etc.tu-bs.de/~chris/

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> BTW, unless you are the news administrator it would be nice if you
changed
> your name to something other than "news.povray.org".
Yes ... just realized this ...
That happens, when you need to reinstall your windows ...
I'm sorry for that ... I hope it's OK now ...


--
background{rgb 1}camera{location<1,5,-2>look_at 0}#macro
m(a,b,i)#local d=(b-a)
/8;#local
e=vcross(d,y);#if(i)m(a-e,a+e+2*d,i-1)m(a+e,a+2*d-e,i-1)m(a+3*d-e,a+e
+3*d,i-1)m(a+3*d-e,a+5*d-e,i-1)m(a+6*d-e,a+e+6*d,i-1)m(a+8*d-e,a+e+8*d
,i-1)#else
cylinder{a,b,vlength(d)/3 pigment{rgb 0}}#end#end m(-4*x,2*x,4) // Jan
Walzer

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"news.povray.org" wrote:
>
> In the lower half the sphere is brighter, than the upper half.
> But I didn't expect such a sharp edge ... Maybe I'm wrong ...

You are not wrong. There seems to be errors in rad calculations when
using background{} color. Replace this:

> background {color rgb <0.0,0.30,0.80>}

With this:

sphere{0,1000
  pigment{color rgb <0,0.3,0.8>}
  finish{diffuse 0 ambient 1}
  no_shadow
}

______________________________________________________________________
Kari Kivisalo                                  http://www.kivisalo.net

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I think I found why you see a "reflection".

> #declare GroundTex=texture {
>                         pigment {checker color rgb 1, color rgb 0.95}
>                         finish {ambient 0 diffuse 0.8}
>                         }

> sphere {y*6,5.5
>         texture {GroundTex
>                 normal {
>                         crackle 1
>                         scale 0.5
>                         }
>                 }
>         }

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