Are you looking for good real-world spacecraft to add to your perfect scene? Or maybe you want to examine the Discovery from 2001: A Space Odyssey up close and personally? The Celestia Motherlode has a superb catalogue of spacecraft both from fiction and reality to explore. What’s more these spacecraft can be placed in an accurate 3D universe contained in the Celestia software or within scenes created from your own 3D applications. There is a large collection of models related to Star Trek, Star Wars, 2001 and Babylon V often available in 3DS format.
What is Celestia?
Celestia, a 3D astronomy program, allows you to travel through a comprehensive universe, which is based on reality. There are almost 120,000 stars contained in it, based on the Hipparcos Catalogue. Models range from small spacecraft to entire galaxies, all represented in three dimensions using OpenGL. The superb advantage of having this universe in 3D is that you can have perspectives which would not be possible from a classic planetarium. Its notable that NASA and ESA have used Celestia in their educational programs. The software was originally created by Chris Laural.
Question and Answers With Ulrich Dickmann
Celestia Motherlode Site Administrator
(original article by Brian Christensen from issue 13 of 3D Art Direct Magazine)
3DAD: How and when did the Celestia Motherlode.net site start. Did it exist in the early days of the Celestia project?
Ulrich Dickmann: The site was conceived by Mr. Joe Bolte in June 2004, three years after the first release of Celestia software. He created the initial Celestia Add-on Catalog web site, which was originally located on the University of Chicago web servers. Since add-ons were scattered around the internet and hard to find we did try to collect, gather and host add-ons with a repository.
3DAD: Tell us how you personally got involved with Celestia. What attracted you to the software?
UD: – I simply did stumble over the 3D astronomy simulator Celestia while I was looking for a planetarium software at the end of 2003. I did download it and expected nothing but another simulator with a more or less undemanding graphics quality. I did install the software and … WOW! What a remarkable graphics quality! You can travel throughout the solar system, to any of over 100,000 stars, or even beyond the galaxy. All movement in Celestia is seamless; the exponential zoom feature lets you explore space across a huge range of scales, from galaxy clusters down to spacecraft only a few meters across while it is simple to navigate through the universe to the object you want to visit.
3DAD: How easy is it to install these models to a copy of Celestia that’s already installed on your system?
UD: – Well, that depends on how the add-on author did set up the add-on. Most of the add-ons you find on the Celestia Motherlode are very easy to install on Windows platforms. Linux users may have to modify some files in order to get the add-on run properly (since Linux is a case sensitive operating system). Each zip file should contain a readme-file with instructions.
3DAD: So all these models are completely free, and created and donated by users from around the world? What does it take to get someone’s model included in this amazing project?
UD: – Yep, all models are completely free (but copyrighted sometimes). To get your model included in the listings of the Celestia Motherlode your add-on have to be really ready for wider distribution, e.g: Does it work properly and offer something new or in better quality? Will other people find it actually interesting?
3DAD: What are the .ssc files that all the models come with, and how do they effect the models?
UD:– This kind of file sets up planets, moons, spacecraft and other orbiting objects in a solar system. It is a *S*olar *S*ystem *C*atalog (SSC). To set up a solar system you also need a .stc file (*St*ar *C*atalog) where you have to define the position of the star in your universe.
3DAD: What are Celestia Virtual Textures (VT) and how do they work?
UD: In its simplest form, a VT is simply a large, hi-resolution image of a planet’s or moon’s surface. This image has been broken down into smaller images (tiles) which are then used by Celestia to display higher resolution images on your computer. The advantage in processing the images this way is that they don’t take up a lot of memory while running on your display screen. Each level of a VT consists of a series of small pictures which are aggregated by Celestia into a whole for your viewing pleasure. If you’re limited to a machine which has no graphics card at all, then VTs can make all of the difference in the world…
3DAD: Tell me about scripts for Celestia; what can you do with them?
UD: – What can you do with them? Everything! Scripts are a kind of a macro you may know from MS Excel or similar.
A Celestia .CEL script is simply a plain-text file that contains a list of instructions for Celestia to carry out automatically. For example, when a default installation of Celestia is run, the on-screen display moves to Jupiter’s moon Io. This action is taken automatically when Celestia is run, via the included startup script. So with a script you are able to show others how space dynamics works, you can present and explain planets and moons and a lot of more.
3DAD: I was looking for the Mir space station, and I couldn’t find it. Why doesn’t it appear in orbit?
UD: Celestia has programmed some of its spacecraft to appear in space and then actually fall back to Earth (disappear) on the day that they really did so. The Russian space station Mir was launched on
02/20/1986 and fell back to earth on 03/21/2001. To see Mir in orbit above the Earth, you will have to reset the date to some period between those two dates.
3DAD: What’s the next step for Celestia? Where do you see this program (and it’s community) going?
UD: Well, that’s hard to say. I think the community will grow since Celestia is in an ongoing progress of development and improvement. E.g. High dynamic range lighting (photorealism), Light scattering model for rings, major UI improvements, advance visual effects… A big step for the next major release (2.0) is to join all operating systems (Windows/Linux/Mac) into one setup file and GUI.