Hi(gh)!

As I mentioned in my posting before, with my Earth model I now use a 
separate sphere for the cloud-only texture. The original cloud-only 
testure bitmap was black to white; to get the cloud-free portions 
transparent, I used the GIMP's Layer/Transparency/Colour to Transparency 
feature.

But obviously, the eastern hemisphere of that bitmap seems to be 
somewhat lighter than the western one; however, when I render a view of 
the North Pole (see below), the clouds-only texture covering the eastern 
hemisphere is not entirely transparent even in its cloud-free parts. 
And, very strangely, this effect does not disappear when I darken the 
eastern portion of the original map!

Here is the code:

union
{
   sphere // Earth, surface
   {
     0, 1
     texture
     {
       pigment
       {
         image_map
         {
           png "solarsys/ev5826_land_ocean_ice_lights_8192.png"
           map_type 1
           interpolate 2
         }
       }
       finish
       {
	ambient 1
	diffuse 0
       }
     }
     texture
     {
       pigment
       {
         image_map
         {
           png "solarsys/ev11612_land_ocean_ice_8192_POV.png"
           map_type 1
           interpolate 2
         }
       }
       finish { F_Standard_Planetary_Surface }
     }
   }
   sphere // Earth, clouds
   {
     0, 1.000783928 // clouds 5 kms above surface
     texture
     {
       pigment
       {
	image_map
	{
	  png "solarsys/cloud_combined_8192a_alpha.png"
	  map_type 1
	  interpolate 2
	}
       }
       finish { F_Standard_Planetary_Surface }
     }
   }
   rotate -y*clock
   SetAxis(bodies[3][10], bodies[3][11])
   scale <bodies[3][1], bodies[3][2], bodies[3][3]>/sc
   translate Pos_Earth/sc
}


What went wrong?

See you in Khyberspace!

Yadgar

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Attachments:
Download '2012-05-13 earth, take 46 - north pole from 12,000 kms.png' (594 KB)

Preview of image '2012-05-13 earth, take 46 - north pole from 12,000 kms.png'

The first thing I'd do is to find the offending layer. Do you
really need all three? Does each texture individually look fine?
What about the cloud layer over a simple one-pigment sphere?

 > radius 1.000783928
 > scale <bodies[3][1], bodies[3][2], bodies[3][3]>/sc
 > translate Pos_Earth/sc

This may be fishing for floating point inaccuracies if you
have astronomical numbers in the bodies array. Did you try
with two simple spheres of radius 1 and 1.1?

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Hi(gh)!

On 14.05.2012 03:30, Christian Froeschlin wrote:

> This may be fishing for floating point inaccuracies if you
> have astronomical numbers in the bodies array. Did you try
> with two simple spheres of radius 1 and 1.1?

Yes, that's it... I scaled both spheres separately and set the global 
scaling factor to 1000 (rather than 13347 before), and the effect 
disappeared (see below)!

See you in Khyberspace!

Yadgar

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Attachments:
Download '2012-05-14 earth, take 47 - north pole from 12,000 kms.png' (629 KB)

Preview of image '2012-05-14 earth, take 47 - north pole from 12,000 kms.png'

> Hi(gh)!
>
> As I mentioned in my posting before, with my Earth model I now use a
> separate sphere for the cloud-only texture. The original cloud-only
> testure bitmap was black to white; to get the cloud-free portions
> transparent, I used the GIMP's Layer/Transparency/Colour to Transparency
> feature.
>
> But obviously, the eastern hemisphere of that bitmap seems to be
> somewhat lighter than the western one; however, when I render a view of
> the North Pole (see below), the clouds-only texture covering the eastern
> hemisphere is not entirely transparent even in its cloud-free parts.
> And, very strangely, this effect does not disappear when I darken the
> eastern portion of the original map!
>
> Here is the code:
>
> union
> {
> sphere // Earth, surface
> {
> 0, 1
> texture
> {
> pigment
> {
> image_map
> {
> png "solarsys/ev5826_land_ocean_ice_lights_8192.png"
> map_type 1
> interpolate 2
> }
> }
> finish
> {
> ambient 1
> diffuse 0
> }
> }
> texture
> {
> pigment
> {
> image_map
> {
> png "solarsys/ev11612_land_ocean_ice_8192_POV.png"
> map_type 1
> interpolate 2
> }
> }
> finish { F_Standard_Planetary_Surface }
> }
> }
> sphere // Earth, clouds
> {
> 0, 1.000783928 // clouds 5 kms above surface
> texture
> {
> pigment
> {
> image_map
> {
> png "solarsys/cloud_combined_8192a_alpha.png"
> map_type 1
> interpolate 2
> }
> }
> finish { F_Standard_Planetary_Surface }
> }
> }
> rotate -y*clock
> SetAxis(bodies[3][10], bodies[3][11])
> scale <bodies[3][1], bodies[3][2], bodies[3][3]>/sc
> translate Pos_Earth/sc
> }
>
>
> What went wrong?
>
> See you in Khyberspace!
>
> Yadgar

Hi, that looks really good, where did you get the high res image maps from??

Cheers Dre

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Am 17.05.2012 07:00, schrieb Dre:

> Hi, that looks really good, where did you get the high res image maps
> from??

NASA has stuff like that; search for "blue marble".

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