Stellarium mod: Nebula Texture Tweaking
Adding new nebula textures to Stellarium is done by adding a record to the nebula_textures.fab file, located in the <config_root>/data directory. This is pretty straight forward - it's a text file with white-space separated fields as follows:
- NGC catalogue number
- Right Ascension (in decimal degrees)
- Declination (in decimal degrees)
- Magnitude
- Angular size
- Rotation
- Name (this should just be an "x")
- Texture filename
- Source / attribution (spaces replaced with underscores)
This is all well and good for getting the general position of the texture correct, but precise placing is very difficult - if a change to the file is made, it must be re-loaded before the changes are visible, and that is only done when Stellarium loads.
Enter the Nebula Texture Tweaking patch. This is a very ugly, but useful patch which applies against the SVN code (revision 2064). It binds the keys F3 - F12 to the following operations:
| Key | Function |
| F5 | Reduce the size of a selected nebula texture |
| F6 | Increase the size of a selected nebula texture |
| F7 | Rotate the texture clockwise |
| F8 | Rotate the texture anti-clockwise |
| F9 | Reduce the right-ascension of the object |
| F10 | Increase the right-ascension of the object |
| F11 | Reduce the declination of the object |
| F12 | Increase the declination of the object |
| F3 | Reduce the amount by which all the above operations do their work |
| F4 | Increase the amount by which all the above operations do their work |
Each time one of these keys is pressed when there is a Nebula object selected, the operation is performed, and the new position is printed on standard output in a form which is similar (although not quite the same as) the record in the nebula_textures.fab file which would position the object in the new location.
This output can be pasted into the nebula_textures.fab file (and massaged a little) to save the changes. I know this is a little manual, but it's enough to be useful. :D