POV-Ray : Newsgroups : povray.binaries.images : Prehistoric colonist ship habitation module parlor revisited (JPG 400x300, 44 KB) Server Time
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  Prehistoric colonist ship habitation module parlor revisited (JPG 400x300, 44 KB) (Message 1 to 6 of 6)  
From: Yadgar
Subject: Prehistoric colonist ship habitation module parlor revisited (JPG 400x300, 44 KB)
Date: 19 Oct 2001 14:20:36
Message: <3BD06DA5.813D7190@ndh.net>
Hi tracers!

In order to smooth out the grainy appearance of the parlor walls' normal
when hit by light at a low angle, I lowered its bump_size
from 0.1 to 0.01, and in fact, it looks better in this respect now. But
there is still the problem of the strangely vertically striated
structure in the wall texture - the wall object isn't scaled at all, and
even if it was so, I would have applied the texture only after scaling.
I'm quite sure that the effect doesn't depend on the light source, using
area_lights instead of ordinary point lights makes no difference.  Any
suggestions?

See you in Khyberspace -
http://www.geocities.com/electricafghan/index-e.html
Afghanistan Chronicle: http://www.ndh.net/home/bleimann/

Yadgar

Now playing: Can't buy me Love, The Beatles


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Attachments:
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colship005.jpg


 

From: JRG
Subject: Re: Prehistoric colonist ship habitation module parlor revisited (JPG 400x300, 44 KB)
Date: 19 Oct 2001 14:26:32
Message: <3bd07058$1@news.povray.org>
Maybe your light source is coincident with a surface?

--
Jonathan.

"Yadgar" <j.b### [at] ndhnet> ha scritto nel messaggio
news:3BD06DA5.813D7190@ndh.net...
> Hi tracers!
>
> In order to smooth out the grainy appearance of the parlor walls' normal
> when hit by light at a low angle, I lowered its bump_size
> from 0.1 to 0.01, and in fact, it looks better in this respect now. But
> there is still the problem of the strangely vertically striated
> structure in the wall texture - the wall object isn't scaled at all, and
> even if it was so, I would have applied the texture only after scaling.
> I'm quite sure that the effect doesn't depend on the light source, using
> area_lights instead of ordinary point lights makes no difference.  Any
> suggestions?
>
> See you in Khyberspace -
> http://www.geocities.com/electricafghan/index-e.html
> Afghanistan Chronicle: http://www.ndh.net/home/bleimann/
>
> Yadgar
>
> Now playing: Can't buy me Love, The Beatles
>
>
>


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From: Yadgar
Subject: New image, after light_source/wall coincidence correction (JPG 400x300, 52 KB)
Date: 20 Oct 2001 20:02:49
Message: <3BD20773.5411C9A8@koh-e-qaisar-observatory.af>
JRG schrieb:

> Maybe your light source is coincident with a surface?
>
> --
> Jonathan.
>
>

Yes, in fact this was the case... the parlor's radius is 5 (centered at x=0,
z=0), the centers of the light cylinders are also placed at a
distance of 5 from the parlor's center. But when I changed their location from
5 to 4.99 (and as well the positions of the objects that go with them, such as
the decorative metallic belts, end caps and textureless "subtraction boxes" to
cut the cylinders in half), the whole scene turned significantly darker and
much grainier than before - but the strange striated wall structure remains,
see attached image!

See you in Khyberspace - http://www.geocities.com/electricafghan/index-e.html
Afghanistan Chronicle: http://www.ndh.net/home/bleimann/

Yadgar

Now playing: Hello, Goodbye (The Beatles)


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Attachments:
Download 'colship006.jpg' (52 KB)

Preview of image 'colship006.jpg'
colship006.jpg


 

From: JRG
Subject: Re: New image, after light_source/wall coincidence correction (JPG 400x300, 52 KB)
Date: 21 Oct 2001 07:19:53
Message: <3bd2af59@news.povray.org>
Hmmm, if I understood you well you have your lights put in CSG objects. If
you're using simple unions, there shouldn't be any problem. If you're using
differences too, which seems the case, then you may want to put your
light_source block outside the difference: i.e.: union { difference
{YOUR_DIFFERENCE} light_source {YOUR_LIGHT_SOURCE}}}. Anyway, if you wanted
to post some code it would be easier to find what is wrong.

--
Jonathan.

"Yadgar" <yad### [at] koh-e-qaisar-observatoryaf> ha scritto nel messaggio
news:3BD20773.5411C9A8@koh-e-qaisar-observatory.af...
> JRG schrieb:
>
> > Maybe your light source is coincident with a surface?
> >
> > --
> > Jonathan.
> >
> >
>
> Yes, in fact this was the case... the parlor's radius is 5 (centered at
x=0,
> z=0), the centers of the light cylinders are also placed at a
> distance of 5 from the parlor's center. But when I changed their location
from
> 5 to 4.99 (and as well the positions of the objects that go with them,
such as
> the decorative metallic belts, end caps and textureless "subtraction
boxes" to
> cut the cylinders in half), the whole scene turned significantly darker
and
> much grainier than before - but the strange striated wall structure
remains,
> see attached image!
>
> See you in Khyberspace -
http://www.geocities.com/electricafghan/index-e.html
> Afghanistan Chronicle: http://www.ndh.net/home/bleimann/
>
> Yadgar
>
> Now playing: Hello, Goodbye (The Beatles)
>
>
>


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----


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From: Yadgar
Subject: Re: New image, after light_source/wall coincidence correction (JPG 400x300, 52 KB)
Date: 22 Oct 2001 15:49:00
Message: <3BD462F4.3B1CA81B@koh-e-qaisar-observatory.af>
Hi Tracers!

JRG schrieb:

> Hmmm, if I understood you well you have your lights put in CSG objects. If
> you're using simple unions, there shouldn't be any problem. If you're using
> differences too, which seems the case, then you may want to put your
> light_source block outside the difference: i.e.: union { difference
> {YOUR_DIFFERENCE} light_source {YOUR_LIGHT_SOURCE}}}. Anyway, if you wanted
> to post some code it would be easier to find what is wrong.
>

Could it be that the rendering is so strange because I cut the very light
source in half by a 'subtraction box'
(the lamp cylinder has a radius of 0.15 while the parlor wall is only 0.1
thick, otherwise it would stick out on the
other side) as follows:

#declare Habitation_Module_Parlor_Lamp_Raw=
light_source
{
   <0, 1.25, 0>
   color rgb 1
   // area_light x, y, 1, 4
   fade_distance 3
   fade_power 2
   looks_like
   {
      cylinder
      {
         <0, -0.75, 0> <0, 0.75, 0>, 0.15
         texture { Light_Tube }
      }
   }
   // adaptive 0
}

#declare Habitation_Module_Parlor_Lamp_Raw_Ring=
union
{
   #declare a=0;
   #while (a<4)
   object
   {
      Habitation_Module_Parlor_Lamp_Raw
      translate <5*sin((-7.5+a*90)*(pi/180)), 0, 5*cos((-7.5+a*90)*(pi/180))>
   }
   #declare a=a+1;
   #end
}

#declare Habitation_Module_Parlor_Lamp_Raw_Ring_Stack=
union
{
   #if (clock=8)
     #declare n=2;
     #declare start=0;
   #else
     #declare n=16;
     #declare start=0;
   #end
   #declare a=0;
   #while (a<n)
   object
   {
      Habitation_Module_Parlor_Lamp_Raw_Ring
      translate y*(10+start*2.5+a*2.5)
   }
   #declare a=a+1;
   #end
}

#declare Habitation_Module_Parlor_Lamp_Subtraction_Box=
box
{
   <-0.2, 0.4, 0> <0.2, 2.1, 0.2>
}

#declare Habitation_Module_Parlor_Lamp_Subtraction_Box_Ring=
union
{
   #declare a=0;
   #while (a<4)
   object
   {
      Habitation_Module_Parlor_Lamp_Subtraction_Box
      rotate y*(-7.5+a*90)
      translate <5*sin((-7.5+a*90)*(pi/180)), 0, 5*cos((-7.5+a*90)*(pi/180))>
   }
   #declare a=a+1;
   #end
}

#declare Habitation_Module_Parlor_Lamp_Subtraction_Box_Ring_Stack=
union
{
   #declare a=0;
   #while (a<16)
   object
   {
      Habitation_Module_Parlor_Lamp_Subtraction_Box_Ring
      translate y*(10+a*2.5)
   }
   #declare a=a+1;
   #end
}

and then

... // declaration of the entire habitation module

  difference
   {
      object { Habitation_Module_Parlor_Lamp_Raw_Ring_Stack }
      object { Habitation_Module_Parlor_Lamp_Subtraction_Box_Ring_Stack }
      texture { Light_Tube }
   }

I will try out an alternative solution this night: cutting already the
fluorescent lamp raw cylinder inside the look_like accolades
in half instead of cutting the whole lamp...

See you in Khyberspace - http://www.geocities.com/electricafghan/index-e.html
Afghanistan Chronicle: http://www.ndh.net/home/bleimann/

Yadgar

Now playing: Spinning Wheel (Blood, Sweat & Tears)


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From: JRG
Subject: Re: New image, after light_source/wall coincidence correction (JPG 400x300, 52 KB)
Date: 23 Oct 2001 13:53:27
Message: <3bd5ae97@news.povray.org>
Ouch! This way is a lotta slower...
1) You can't use lightsources in differences.
2) Do not make differences which involve many scattered objects: the
bounding box will fill the whole scene and the rendering will be extremely
SLOW.
3) Why are you bothering trig, when it's much easier and faster to place
your bulbs with *rotate*? Just use: object {YOUR_BULB translate RADIUS
rotate ANGLE*y}

Try something like this (not tested, and I left the trig part, which IMO
should be substituted with rotate):

#declare Habitation_Module_Parlor_Lamp_Raw=
light_source
{
   <0, 1.25, 0>
   color rgb 1
   // area_light x, y, 1, 4
   fade_distance 3
   fade_power 2
   looks_like
   {  difference {
      cylinder
      {
         <0, -0.75, 0> <0, 0.75, 0>, 0.15 }
      box // your cutting box. Remember that you can also use a cutting
plane.
{
   <-0.2, 0.4, 0> <0.2, 2.1, 0.2>
}

         texture { Light_Tube }
      }
   }
   // adaptive 0
}

#declare Habitation_Module_Parlor_Lamp_Raw_Ring=
union
{
   #declare a=0;
   #while (a<4)
   object
   {
      Habitation_Module_Parlor_Lamp_Raw
      rotate y*(-7.5+a*90)

      translate <5*sin((-7.5+a*90)*(pi/180)), 0,
5*cos((-7.5+a*90)*(pi/180))>
   }
   #declare a=a+1;
   #end
}

#declare Habitation_Module_Parlor_Lamp_Raw_Ring_Stack=
union
{
   #if (clock=8)
     #declare n=2;
     #declare start=0;
   #else
     #declare n=16;
     #declare start=0;
   #end
   #declare a=0;
   #while (a<n)
   object
   {
      Habitation_Module_Parlor_Lamp_Raw_Ring
      translate y*(10+start*2.5+a*2.5)
   }
   #declare a=a+1;
   #end
}


// declaration of the entire habitation module
      object { Habitation_Module_Parlor_Lamp_Raw_Ring_Stack
      texture { Light_Tube }
   }

Hope this helps,

--
Jonathan.


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