Celestia Forums

Can somebody give me a few pointers on getting these textures to work?

FOr example: I have downloaded a high res set of mars textures, the set includes A main dds file as well as png files for the bumpmaps and the clouds. I have my soler system data file edited like this for mars

"Mars" "Sol"
{
Texture "mars.dds"
BumpMap "Mars-Bump.png"
BumpHeight 2.5
Color [ 1 0.75 0.7 ]
HazeColor [ 1 1 1 ]
HazeDensity 0.45
Radius 3394
# Oblateness 0.006

Atmosphere {
Height 30
Lower [ 0.8 0.6 0.6 ]
Upper [ 0.7 0.3 0.3 ]
Sky [ 0.83 0.75 0.65 ]
CloudHeight 7
CloudSpeed 65
CloudMap "mars-Clouds.png"
}

CustomOrbit "vsop87-mars"
EllipticalOrbit
{
Period 1.8809
SemiMajorAxis 1.5237
Eccentricity 0.0934
Inclination 1.8506
AscendingNode 49.479
LongOfPericenter 336.041
MeanLongitude 355.453
}

RotationPeriod 24.622962
Obliquity 26.72
EquatorAscendingNode 82.91
RotationOffset 136.005

Albedo 0.150
}

I see a much better looking mars with this but i could swear i'm not seeing any bumpmapping it still looks rather flat, i've seen some pics with much better results, what am i doing wrong here? I have the latest version of celestia 1.30 as well as a video card thats perfectly capable of running this stuff, gf4 ti 4600.

Also if i wanted to use a normal map insted of a bumpmap would i just add NormalMap "mapname.dds" assuming it's a dds file?

Thanks for any help.

-Zeejay-

Zeejay wrote:Can somebody give me a few pointers on getting these textures to work?

FOr example: I have downloaded a high res set of mars textures, the set includes A main dds file as well as png files for the bumpmaps and the clouds. I have my soler system data file edited like this for mars

"Mars" "Sol"
{
Texture "mars.dds"
BumpMap "Mars-Bump.png"
BumpHeight 2.5
Color [ 1 0.75 0.7 ]
HazeColor [ 1 1 1 ]
HazeDensity 0.45
Radius 3394
# Oblateness 0.006

Atmosphere {
Height 30
Lower [ 0.8 0.6 0.6 ]
Upper [ 0.7 0.3 0.3 ]
Sky [ 0.83 0.75 0.65 ]
CloudHeight 7
CloudSpeed 65
CloudMap "mars-Clouds.png"
}

CustomOrbit "vsop87-mars"
EllipticalOrbit
{
Period 1.8809
SemiMajorAxis 1.5237
Eccentricity 0.0934
Inclination 1.8506
AscendingNode 49.479
LongOfPericenter 336.041
MeanLongitude 355.453
}

RotationPeriod 24.622962
Obliquity 26.72
EquatorAscendingNode 82.91
RotationOffset 136.005

Albedo 0.150
}

I see a much better looking mars with this but i could swear i'm not seeing any bumpmapping it still looks rather flat, i've seen some pics with much better results, what am i doing wrong here? I have the latest version of celestia 1.30 as well as a video card thats perfectly capable of running this stuff, gf4 ti 4600.

Also if i wanted to use a normal map insted of a bumpmap would i just add NormalMap "mapname.dds" assuming it's a dds file?

Thanks for any help.

-Zeejay-

All file names in solarsys.ssc must /exactly/ correspond to the respective names of your new files in textures/hires. Watch out for typos! Check capital letters etc.

Increase the BumpHeight to 10.0 for example. Then you should definitely see something.

Check for Mercury (1 G), you should see a bump map effect there by default.

Bye Fridger

Zeejay,

Celestia v1.3.0 final has a bug in the bumpmap code which was introduced when Chris tried to fix a bug in the normalmap code. The Windows version of v1.3.0 pre6 is available in http://www.shatters.net/celestia/files/. Bumpmaps work fine in that version, although of course that version does still have the normalmap bug.

(Fridger probably has forgotten about this since he compiles from scratch from the source code on SourceForge. Hopefully v1.3.1 will be available soon.)

Now can someone explain the difference between a bumpmap and a normalmap? Sorry for the rather stupid question...

A bumpmap is a grey-scale image with the "whiteness" of each pixel proportional to the altitude of the pixel.

A normalmap is a color image with the rgb components of each pixel proportional to the xyz components of the surface normal vector of the pixel.

A "surface normal vector" specifies the direction which is perpendicular to the surface at that point. If it points away from a light source, it's in shadow. If it points toward a light source, it's illuminated.

3D graphics cards use normalmaps internally. Celestia has to translate bumpmaps into normalmaps. Most bumpmaps are only 8bit greyscale, so they aren't very accurate. normal maps can include somewhat more precision.

See http://members.shaw.ca/jimht03/normal.html for an illustrated explanation.