POV-Ray : Newsgroups : povray.animations : Where is the failure Server Time: 18 Jun 2019 17:33:45 GMT
  Where is the failure (Message 1 to 6 of 6)  
From: Roland Mösl
Subject: Where is the failure
Date: 15 Nov 2011 08:43:50
Message: <4ec22646@news.povray.org>
#declare terra_class = union
{
   sphere { <0,0,0> 100 }
   sphere { <70,0,-70> 8 rotate <0,0, 15> }
   sphere { <70,0,-70> 8 rotate <0,0, 75> }
   sphere { <70,0,-70> 8 rotate <0,0,135> }
   sphere { <70,0,-70> 8 rotate <0,0,195> }
   sphere { <70,0,-70> 8 rotate <0,0,255> }
   sphere { <70,0,-70> 8 rotate <0,0,315> }
   torus { 95 20   rotate <90 0 0> }
   texture { t_metall }

}

I thought the smaller spheres should be 45% visible on the biger sphere,
but they are not.

I can not find my failure

--
Roland Mösl


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From: Stephen
Subject: Re: Where is the failure
Date: 15 Nov 2011 09:07:52
Message: <4ec22be8@news.povray.org>
On 15/11/2011 8:43 AM, Roland Mösl wrote:

> I thought the smaller spheres should be 45% visible on the biger sphere,
> but they are not.
>
> I can not find my failure
>

Where is your camera?

They are visible to me when my camera is:

camera {
  perspective
  location <-0.891,7.168,-594.751>
  up y
  right 1.333*x
  angle 33.000
  sky <-0.000,1.000,-0.020>
  look_at < 0.449, 18.943, 0.102 >
}


-- 
Regards
     Stephen


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From: Roland Mösl
Subject: Re: Where is the failure
Date: 15 Nov 2011 18:00:48
Message: <4ec2a8d0$1@news.povray.org>
On 2011-11-15 10:07, Stephen wrote:
> On 15/11/2011 8:43 AM, Roland Mösl wrote:
>
>> I thought the smaller spheres should be 45% visible on the biger sphere,
>> but they are not.
>>
>> I can not find my failure
>>
>
> Where is your camera?
>
> They are visible to me when my camera is:
>
> camera {
> perspective
> location <-0.891,7.168,-594.751>
> up y
> right 1.333*x
> angle 33.000
> sky <-0.000,1.000,-0.020>
> look_at < 0.449, 18.943, 0.102 >
> }

more in the - in the z axis, here the szene
was for a 12 second scene, where 4 Perry Rhodan style spaceships
fly, Earth and Moon in the background

BTW, it's so different from SF movies.
In SF movies are spaceships always lighted from all sides to
be good visible.

#declare t_metall = texture
{
   pigment { color red 0.51 green 0.69 blue 0.70 }
   finish
   { brilliance 8.0
     phong 1.0
     phong_size 80
     reflection 0.75
     ambient 0.01
   }
}


#declare terra_class = union
{
   sphere { <0,0,0> 100 }
   sphere { <70,0,-70> 8 rotate <0,0, 15> }
   sphere { <70,0,-70> 8 rotate <0,0, 75> }
   sphere { <70,0,-70> 8 rotate <0,0,135> }
   sphere { <70,0,-70> 8 rotate <0,0,195> }
   sphere { <70,0,-70> 8 rotate <0,0,255> }
   sphere { <70,0,-70> 8 rotate <0,0,315> }
   torus { 92.5 20   rotate <90 0 0> }
   texture { t_metall }

// 2011-11-15 change scale from m to km
   scale <0.001, 0.001, 0.001 >
}


#declare start_point = -499950;
#declare speed = 6;

object { terra_class translate < 0.6, 0.1, start_point +  0 - clock * 
speed> }
object { terra_class translate <-0.6,-0.1, start_point +  5 - clock * 
speed> }
object { terra_class translate < 0.2,-0.1, start_point + 10 - clock * 
speed> }
object { terra_class translate <-0.2, 0.1, start_point + 15 - clock * 
speed> }


object
{ sphere  { <0,0,0> 12757/2 }
   pigment { image_map { png "map-earth.png" map_type 1 interpolate 2 } }
   finish  { ambient 0 }
   rotate  < 0, -30, 0 >
   translate <-8000,0,0>
}  // object


object
{ sphere  { <0,0,0> 3467/2 }
   pigment { image_map { png "map-moon.png" map_type 1 interpolate 2 } }
   finish  { ambient 0 }
   rotate  < 0, 90, 0 >
   translate <3500,0,-380000>
}  // object

light_source { <-149000000, 0, 0> color <1 1 1> } // light_source
light_source { <-149000000, 0, 0> color <1 1 1> } // light_source
light_source { <-149000000, 0, 0> color <1 1 1> looks_like { sphere { 
<0,0,0> 1350000/2 color <1,1,1> } } } // light_source

camera
{ location <0, 0, -500000>
   direction <0 0 1>
   up <0 1 0>
   sky <0 1 0>
   right <16/9, 0, 0>
   look_at <0 0 0>
   angle 4
}  // camera


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From: Christian Froeschlin
Subject: Re: Where is the failure
Date: 15 Nov 2011 20:13:25
Message: <4ec2c7e5@news.povray.org>
Roland Mösl wrote:

> light_source { <-149000000, 0, 0> color <1 1 1> } // light_source
> light_source { <-149000000, 0, 0> color <1 1 1> } // light_source
> light_source { <-149000000, 0, 0> color <1 1 1> looks_like { sphere { 
> <0,0,0> 1350000/2 color <1,1,1> } } } // light_source

You will usually run into numerical problems when attempting
to model meter-sized objects in a solar system scale. You can
avoid such problems by modelling the small objects near the
origin at the meter scale and then faking the rest by using
planets and stars that are too close but also too small.

Also, having multiple light sources at the same position
doesn't seem to be useful. Note that the brightness is not
limited to 1 and using color rgb 3 will work just fine.


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From: Stephen
Subject: Re: Where is the failure
Date: 15 Nov 2011 20:21:22
Message: <4ec2c9c2$1@news.povray.org>
On 15/11/2011 6:00 PM, Roland Mösl wrote:
> more in the - in the z axis, here the szene
> was for a 12 second scene, where 4 Perry Rhodan style spaceships
> fly, Earth and Moon in the background
>

It is looking good.
Did you know that you do not need three light sources but can have one 
light source with brightness greater than one?

color <3 3 3 > or color <1 1 1> * 3

> BTW, it's so different from SF movies.
> In SF movies are spaceships always lighted from all sides to
> be good visible.

Artistic licence. :-)
Using that you could add a very little ambient to your planets to give a 
hint of the darkside.

-- 
Regards
     Stephen


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From: Alain
Subject: Re: Where is the failure
Date: 17 Nov 2011 03:27:30
Message: <4ec47f22@news.povray.org>
Le 2011/11/15 15:13, Christian Froeschlin a écrit :
> Roland Mösl wrote:
>
>> light_source { <-149000000, 0, 0> color <1 1 1> } // light_source
>> light_source { <-149000000, 0, 0> color <1 1 1> } // light_source
>> light_source { <-149000000, 0, 0> color <1 1 1> looks_like { sphere {
>> <0,0,0> 1350000/2 color <1,1,1> } } } // light_source
>
> You will usually run into numerical problems when attempting
> to model meter-sized objects in a solar system scale. You can
> avoid such problems by modelling the small objects near the
> origin at the meter scale and then faking the rest by using
> planets and stars that are too close but also too small.
>
> Also, having multiple light sources at the same position
> doesn't seem to be useful. Note that the brightness is not
> limited to 1 and using color rgb 3 will work just fine.

A single light_source with rgb 3 will also be about 3 times faster than 
those 3 light_source with rgb 1.
In the first case, you only do a single illumination/shadow test.
In the second case, you need to do 3 of those: One for each lights.


Alain


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