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A newbie

Posted: 13.05.2005, 16:03
by Art_Erickson
I just started playing with this wonderful app and thought I'd try adding the "Stage 13 (Complete)" (for the ISS) addon from the celestiamotherlode site. I started by reading the various FAQ and users guides so I have made some progress. Note: using the Search function to locate information in the forum could be refined - I don't think it uses a rating system to give you the most relevant topics (based on keyword hits) first.
I was able to d/l the isscomplete.3ds file and the textures and put them in the proper subdirectories (C:\ProgramFiles\Celestia\extras\ISScomplete\data, etc.) but it was not going to be that easy :) I decided I needed a .ssc file so I copied the one for the ISS in the spacecraft.ssc file and modified for my use. I named it ISScomplete.ssc and put it in my data dirctory for ISScomplete (in the extras directory) hoping Celestia would pick it up automatically - ah, well :)
Then I decided to put the ID section (the copy if the ISS section from the spaceraft.ssc file) I had created into the spacecraft.ssc file itself. After a little trial and error the ISScomplete option appeared in the spacecraft section of the Earth context menu. Hurray for me :)
The problem is, it still uses the image from the original ISS object. I tried playing with the path to the mesh but that didn't help. I put the ISScomplete.3ds file in the Celestia models directory and now it displays both images - the original ISS and ISScomplete. It doesn't display the textures for ISScomplete but I presume that is because I didn't put them into the Celestia textures directory.
Has anyone else tried this before? I believe I'm just missing a fundimental bit of knowlege about how this app works.

Thanks in advance,

Art

Posted: 13.05.2005, 16:33
by selden
You might take a look at http://www.lepp.cornell.edu/~seb/celest ... intro.html
It should help clarify what needs to be where.

Please let me know what can be improved.

Posted: 13.05.2005, 16:40
by bh
Hello Art - glad you're having fun with the fantastic ISS model. You need to download the texture pack for this model into your textures/medres directory...

regards...bh.

Posted: 13.05.2005, 17:34
by Art_Erickson
Hi guy's, thanks for the assist. I did indeed go to the http://www.lepp.cornell.edu/~seb/celest ... intro.html site and found that to start a little farther along than I was. I wasn't trying to add a true astronomical entity (planet, star, etc.) just add a little 'ol spacecraft to Earth. I really did think I was starting out with an easy one. I'm not nearly smart enough (yet, anyway) to offer suggestions for the improvement of this help file but I certainly will if I think of one.


I do not believe I need a separate .ssc file at all. I just need to add the ISScomplete info to the spacecraft.ssc file I believe it will co-exist with the orginal ISS object just fine - if I do this right. I believe the problem is with getting the spacecraft.ssc file to tell Celestia where the model and the textures for the ISScomplete object are and to not display the original ISS image.


I just went to the http://members.fortunecity.com/guilpain ... ssc_uk.htm site and it did give a little more info. It states, "Generally one does not use the functions Textures and Mesh together because the models are already textured, the Texture function is thus useful only for the planets and moons, spherical by default." but I would think many objects use both models (called mesh?) and textures. From this example it looks like I need to add the textures to the ssc file with tags. Hmmm, I hope not.

I believe bh may well be correct that I need to add the textures to the Celestial /textures/medres directory but that is contrary to the instructions to create separate directories for each addon under the extras directory.

I see this as a path problem. I need to use the correct sytax with the mesh tag and the textures tag. All the examples I've seen just use the file name.

Thanks again.

Art

Posted: 13.05.2005, 18:49
by TERRIER
The problem is, it still uses the image from the original ISS object.


This is the .ssc file settings I am using for the current "true-life" version of the ISS, which is stage 11A, for which a model is currently available;

Code: Select all

"ISS-11A" "Sol/Earth"
{
  Class "spacecraft"
  Mesh  "iss_11A.3DS"
  Radius  0.030
Beginning 2452602 # P1 Truss Launch Nov 23, 2002

  EllipticalOrbit  #Updated 11-Mar-2005
{
Period  0.06366559      
    SemiMajorAxis  6735.005      
    Eccentricity  0.0003655      
    Inclination  51.6451      
    AscendingNode  40.3534      
    ArgOfPericenter  182.4940
    MeanAnomaly  177.6204
    Epoch  2453441.05712646      
  }      
  Obliquity  51.6451      
  EquatorAscendingNode  40.3534      
  RotationOffset  300.6148      
  Orientation  [ 180 1 0 0 ]   
Albedo 0.10
}


Don't forget that you need to change the name in the Mesh "................3ds" line of the code to exacly match that of the model you are wanting to use.

regards,
TERRIER

Posted: 13.05.2005, 18:49
by selden
Art,

3D models that need to use more than one surface texture image (which is most of them, especially the ISS models) have to specify the names of their texture image files within the model files themselves. There's no need to spacify any Texture in the associated SSC definition. Texture files that are specified in 3D model files (3DS or CMOD meshes) must be in the folder /textures/medres/ that's associated with a particular Addon.

You can't specify more than one Texture in an entry in an SSC catalog file. If you do specify one, that one texture will then be applied in place of all of the different textures in the model, which probably is not what you want.

In general, it's best not to modify any of the SSC catalog files that come with Celestia. An SSC file for the Addon usually works best. If you want to replace the default ISS, then specify either specify it with a Replace or a Modify:

This would replace Celestia's ISS model by the "complete" model, for example, leaving all the other parameters unchanged:

Code: Select all

Modify "ISS" "Sol/Earth" {
           Mesh "isscomplete.3ds"
}



Does this clarify things a little?

Limited Success

Posted: 13.05.2005, 19:28
by Art_Erickson
AHA, much better! I am still digesting what you have told me but just by commenting out (I know, I should used Replace as suggested but I'm not too bright :) ) the original ISS definition in the spaceship.ssc file I now get only one image. I was hoping to leave the original so I could have multiple images to use as I wished. Here is where the replace function may come in, but it does make me alter ther file before launching Celestia. I'll clean this up when I have a little more experience (I haven't done anything major yet).

I agree Sheldon that, "In general, it's best not to modify any of the SSC catalog files that come with Celestia." but, sadly, the best way I learn a new app is to break it and then learn how to fix it. I haven't broken Celestia yet so I need a little more time. You might say my feet have many scars from the bullet holes :)

Terrier, do you put all your files in the original Celestia directories or do you create a subdirectory structure in the extras folder like the user manuals suggest? Getting the path right is the last part of this puzzle.

Re: Limited Success

Posted: 13.05.2005, 20:16
by TERRIER
Art_Erickson wrote:
Terrier, do you put all your files in the original Celestia directories or do you create a subdirectory structure in the extras folder like the user manuals suggest? Getting the path right is the last part of this puzzle.


I installed my ISS add-on, quite a while ago, before any of the "new" .ssc commands such as Modify, Replace ( and I think there's another one that I can't remember at present. :roll:). I've never altered it, because it works OK.

Basically I hashed out (#) all the default ISS .ssc file code in the spacecraft.ssc which is found in the main Data directory, and added a new ISS folder in the main Extras directory, under a subdirectory which I call Spacecraft.

In summary, my ISS add-on folder is installed inside the following folders;

Celestia -> Extras -> Spacecraft

Inside my ISS folder I have many .ssc files for all the different stages of the ISS, where models are available. I also have a file named models, where all the 3d model files are kept, and finally a textures file, which inside contains a medres file where all the appropriate textures for the models are located.

In summary, my ISS folder contains the following folders/ files;

ISS -> various .ssc files
-> models -> various 3d model files
-> textures -> medres -> various texture files that apply to the ISS models

I hope this is clear to understand ?

regards,
TERRIER

Directory structure

Posted: 13.05.2005, 21:31
by Art_Erickson
Terrier,

It is clear. It is the way I have set up my ISS addon except I didn't use a Spacecraft top level directory. Also, I put a medres subdirectory in the textures directory.

Well by jingies! I just put everything back to, what I thought was, my original configuration and now it works. True, you can't have the original ISS in the spacecraft.ssc file, but the spacecraft selection box for earth is automatically populated with the new ISS. Actually I'm glad it didn't work the first time because I learned so much more this way.

When the holes in my feet heal I may be brave enough to take on a more complicated object. After I use this awhile I hope to better understand the interface and how to get from one place to another. I ran across an image I can d/l with the commands, I'll go find that again.

Many thanks to you all for such prompt and considerate help.

Art