\extras\folder. This causes Celestia to look for the models and textures in the wrong places.
\extras\folder into the Addon's main folder.
For example, all of the files that are in
must be moved into
Then delete the now-empty
Originally Addons had to put their files in among the files
that come with Celestia. The Zip file of one of these older Addons
\extras\ folder which corresponds to
\extras\ folder. It contains the Addon's catalogs.
Celestia v1.3.0 and later is confused by this and will look
in the wrong place for the models and surface texture images.
Also, if you're running Linux, the case of the letters in the file's name matters. The case of the letters has to be exactly the same in the 3DS file as is used for the filename itself. Linux is case-sensitive, but Windows is not. As a result, some Addons which work fine under Windows fail under Linux. It's safest to change the name of the surface texture image file(s) to be exactly the same as is specified in the 3DS model. It's essentially impossible to fix a damaged 3DS model, but easy to rename a file.
One possible workaround is to
disable the "medres" planetary images provided with Celestia. The lores
surface textures only need about half as much graphics memory.
One way this can be done is to rename the folder
\Celestia\textures\medres\ to be
The "surface normal vectors" specify the direction from which the surface is visible as well as determining how each surface patch gets shaded by light sources. If the normal points away from the observer, Celestia will not draw that patch. Some 3D display programs draw all of the patches no matter what directions their vectors point.
If you don't tell me that something's missing, unclear or wrong, I can't improve it.