Questions on Textures and Finding Objects

[Andrewski]

Hi, new here; bear with me.

I have perused the manual and the links page for some nifty textures. I've gotten Earth to look quite nice, with a bump map and everything. My question is: considering I don't have the greatest video card (GeForce 2 MX... 64?), which file types are the best for speed v. quality for textures? I noticed a few different names thrown around out there, but no explanation anywhere I looked.

Secondly, I imported a galaxy, a cluster, and a messier object plugins, hoping to use them. But I can't figure out how to get to the objects. I had put in the Rosetta Nebula one (great!) and figured out that I had to type ngc2237 to get it. Why I can't type rosetta nebula I don't know. However, typing "m46" or "m 46" didn't register at all, though I have both open clusters and Messier objects imported. Any tips?

Finally, anyone know of any more plugins like the Rosetta one... or the black hole one? Don't patronise my newbie-eye-candy-wanting habits too much, but they're fun!

Thanks a lot,
AC

[selden]

AC,

I'm guessing those are my catalogs you mean. It'd be best if you could specify the exact names of the add-ons. I'm sure there will be competing ones at some point.

Unfortunately "it works fine for me".
When you type a name, you have to match exactly the name that's used in the catalog file. in this case it's "m46" (no space and without the quotes, but capitalization doesn't matter).

I assume you're running Windows. Check to make sure that Windows isn't hiding the actual extension from you. Sometimes it'll gratuitously append ".TXT" when it downloads a .DSC file, making the name into something like "messier_open.dsc.txt" That spurious .txt filetype has to be removed before Celestia can use the file.

One way to check that a catalog add-on has been loaded is to enable "galaxy labels" and expand Celestia's field of view using the "." key. With a large field of view, there should be lots of bright yellow names visible.

Another thing you can do is manually turn Celestia to point in the direction where they are located on the sky to see if they're where they should be.

Also, don't forget that the open cluster addons only provide labels and locations, not objects. Many of the stars that are members of the clusters are already included in Celestia. They're best seen by staying in the solar system and looking toward them. If you incorporate the 2 million star addon, you'll see more of them.

Does this help?

[selden]

AC,

Celestia's ability to display extra-solar eye candy like nebulae is a very new addition, so there aren't many yet.

Prasepe has created one of the horsehead nebula region. See his Web page at http://www.la-guarida.com/Celestia/index_archivos/slide0001.htm

I'v created a few example "billboards" that are at http://www.lns.cornell.edu/~seb/celestia/billboard.html

I hope this helps.

[selden]

AC,

finally, in regard to textures, your card supports them, so DDS files will losd more quickly than JPEG or PNG files because that format is used by the hardware. Usually the larger files will produce better images if the person who created them was careful.

[Andrewski]

Selden,
First of all, thanks for such a great site. I had perused it, and it's where I got most of the plugins I have.

I should have been a bit more clear. I was able to get the galaxy file working, just not the open cluster one. I do have the additional stars put in, and I did type m46 without the quotes, but it doesn't seem to be working. The extension is indeed .dsc, and I even found the names of all the clusters while opening the file in Notepad. (I subsequently had a hunch I would type what was in there.) Is there anything I need to do in the solarsys file? Or is there a way to label the clusters?

Random question: Could I add an additional name to an object? Example: change "NGC2237" to "NGC2237" "Rosetta Nebula".

About the textures, is there any way to change a jpeg file to a dds one? I found a really nice bump map for Earth (I think it was called "ocean floor" or something), but I only found it in jpeg. Now, it takes my computer about 15 seconds to go to Earth. Not unbearable, but I wonder....

Thanks for your help!
AC

[Sum0]

Someone else can field the DDS conversion question (it's messy), but it sounds like to view the cluster you need Rassilon's Globular Cluster Generator, avaliable on this page.

[Andrewski]

No, I'm speaking specifically of Selden's open cluster file, messier_open.dsc. I found it on his site, and after importing it (so I hope) I can't figure out how to turn on the labels or how to find the objects (by typing them in).

The globular clusters I have came with galaxies and are now in my galaxy.dat file. Those work fine.

[selden]

Andrew,

If you really do mean that galaxies.dat works for you, and you are not using galaxies-extended.dsc, then you are running Celestia v1.2.5. galaxies.dat does not work at all with Celestia v1.3.0.

DSC files require Celestia v1.3.0. They don't work with Celestia v1.2.5 or earlier.

[Andrewski]

Ok, I got it. I had to move the messier_open.dsc file to the extras folder, not the data folder. Whoops!

A few more questions:
1. How do I get that red square that comes up when I select an object to come back? It disappeared on me!

2. I have the 2k star database, but most of the open clusters I found were starkly sparse, even with the magnitude turned up to 15. Is that to be expected?

3. How do I manipulate the different resolutions? I'd like to make some of the larger textures appear on hires only; is that possible?

Thanks!
AC

[Andrewski]

Oh, and is there any way to label added objects (like the open clusters or planetary nebulae I've added)?

[selden]

0) Please read http://www.lns.cornell.edu/~seb/celestia/addon-intro.html for a description of one way you can organize add-ons.

1) That little square is a Mark. It's a recent addition to Celestia and does not seem to have made it into any of the menu options available under Windows. Type a Control-K to toggle it on and off. If it's on when you exit from Celestia, it'll be on when you start it up again.

You can "permanently" Mark the object that is currently selected, but only for the duration of the current run of Celestia, by using the right-mouse-button pop-up menu.

2) The Hipparcos satellite was used to measure the parallax of selected stars. Those are the only stars available in Celestia's binary star data format. The people responsible for creating those files for Celestia are frustrating over how to improve them.

The relative positions of many stars in many open clusters have been estimated using other methods. As yet, nobody has translated any of those catalogs into STC or binary catalog files that Celestia can use.

3) There are three texture directories: lores, medres & hires. Image files with the same name can be put into all three of them. Use the keyboard commands "r" and "R" to select among them. "R" = display the file that's in the next higher resolution directory, "r"= next lower resolution directory. Celestia starts by looking in the medres directory. Delete the files you don't want to see. Only the remaining ones will be visible. E.g if only the hires version is available, that's all Celestia will show.

4) I'm not quite sure what you're asking. The name you specify for a Nebula, OpenCluster or Galaxy in a DSC file does get shown.

At the moment, only stars can have more than one name for the same object. However, you can define multiple objects with identical positions but with different names.

The names of all objects in all DSC files appear when you enable rendering of galaxy labels, although this may change. Also, all DSC object labels have the same coloring. There currently is no way to distinguish among them by specifying a special color or different position offset for the labels of particular objects.

I hope this helps.

[Andrewski]

Yes, it does help. Thanks!

[John Van Vliet]

AHH the .dds ? . this is a very fun ? there isnt that mutch that i have found written about it . Iv'e learned by trial and error . I do have .dds textures
for Mercury,Venus,Earth, Moon,Mars,Demois ,Phobos Jupiter ,Amathia,callisto,ganimead,Io ,Europa on my site

click on the link below