 |
|
|
|
|
|
| |
| |
|
|
From: Jörg 'Yadgar' Bleimann
Subject: Image_map with alpha channel: strange effect
Date: 13 May 2012 11:51:23
Message: <4fafd87b@news.povray.org>
|
|
|
| |
| |
|
|
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
Post a reply to this message
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'
|
|
| |
| |
|
|
From: Christian Froeschlin
Subject: Re: Image_map with alpha channel: strange effect
Date: 13 May 2012 21:30:25
Message: <4fb06031$1@news.povray.org>
|
|
|
| |
| |
|
|
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?
Post a reply to this message
|
|
| |
| |
|
|
From: Jörg 'Yadgar' Bleimann
Subject: Re: Image_map with alpha channel: strange effect
Date: 14 May 2012 05:16:57
Message: <4fb0cd89@news.povray.org>
|
|
|
| |
| |
|
|
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
Post a reply to this message
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'
|
|
| |
| |
|
|
From: Dre
Subject: Re: Image_map with alpha channel: strange effect
Date: 17 May 2012 01:00:17
Message: <4fb485e1@news.povray.org>
|
|
|
| |
| |
|
|
> 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
Post a reply to this message
|
|
| |
| |
|
|
From: clipka
Subject: Re: Image_map with alpha channel: strange effect
Date: 17 May 2012 03:36:27
Message: <4fb4aa7b@news.povray.org>
|
|
|
| |
| |
|
|
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".
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
|
|
