Celestia Forums

This is a wonderful program (as you'll notice since I already got into coding it not long after dl'ing it for the first time - see the developer's section for a patch to add all sorts of types of information to Celestia). However, there are some significant issues I've hit - most notably, performance.

I have two very fast computers that I've tried it on, both with fairly good video cards. They get a minimally acceptable performance on normal space scenes. With galaxies turned on, that performance drops to near nil. Likewise, when you land on a planet, the same thing happens.

Is there any way, persay, that we could have an option to adjust the polygon count being used in Celestia? Pretty please? Especially on galaxies; they're mind-bogglingly slow. It almost feels like they're being raytraced.

OS: Linux (Redhat 9.0 and 7.3)

Rei wrote:This is a wonderful program (as you'll notice since I already got into coding it not long after dl'ing it for the first time - see the developer's section for a patch to add all sorts of types of information to Celestia). However, there are some significant issues I've hit - most notably, performance.

I have two very fast computers that I've tried it on, both with fairly good video cards. They get a minimally acceptable performance on normal space scenes. With galaxies turned on, that performance drops to near nil. Likewise, when you land on a planet, the same thing happens.

Is there any way, persay, that we could have an option to adjust the polygon count being used in Celestia? Pretty please? Especially on galaxies; they're mind-bogglingly slow. It almost feels like they're being raytraced.

OS: Linux (Redhat 9.0 and 7.3)

I cannot follow your statements. I am developing Celestia under (SuSE) Linux since about one year. My equipment is fairly old: 1GHz PIII/512MB RAM-CL2, GeForce2 GTS/32MB (!). Yet I am the person that runs those monster textures of 16kx8k (see the textures department) with typically 15fps with galaxies switched on of course...With the default textures of the celestia distribution I am always ranging at around 50fps at 1600x1200 resolution and 16bit color, which sounds acceptable to me, at least;-)

Very few people have complained here about Celestia's performance! And those who did, usually, were using old graphics drivers...

How many fps do you get with glxgears in 16bit color, say? What's your graphics equipment? Drivers? Add-ons? Asteroids? 2MB star data?

We cannot help, if you make no concrete statements about all this...Just costs time...

Bye Fridger

Celestia works very well in my Linux machine too (with the 2M stars database included), and I have a *old* graphics card:


P4 2.4 Ghz, 256Mb RAM, Riva TNT2 32Mb (but almost the latest nVidia drivers)

At work:
Dual Intel Xeon 1.8GHz (3578.26 bogomips each)
NVidia GeForce 2 MX (generic)
1600x1200x16bpp

At home:
1.2GHz Athlon (2385.81 bogomips)
ATI Rage 128 Pro Ultra
1280x1024x16bpp

As I'm not a gamer, I don't have any games to compare it to.

Could the problem be the res/bpp? Still, it's quite slow even with the window at a small size, indicating that the pixel draw speed isn't the problem.

Work and home are about the same speed, even though my work computer is clearly better.

How hard would being able to control the polygon count be?

I don't notice any difference really between using 2 mil stars & asteroids, and using the defaults; especially since the biggest slowdown is from galaxies & from planet surfaces.

Rei wrote:
As I'm not a gamer, I don't have any games to compare it to.

Your card at home may really be somewhat slow...But the equipment at work should be /by far/ fast enough for the default textures. Provided your hadware 3d support is correctly working. To check that I had asked you to quote the fps with the standard XFree86 tool glxgears. This has nothing to do with gaming. At work you should get more than 2000fps under 16bpp with glxgears.

Could the problem be the res/bpp? Still, it's quite slow even with the window at a small size, indicating that the pixel draw speed isn't the problem.

why don't you hit the "`" key and tell us the fps you are getting. Perhaps your notion of slow is different from mine;-)?

Work and home are about the same speed, even though my work computer is clearly better.

This points towards the suspicion that your 3d hardware support is not working correctly!

Bye Fridger

I suspect that you are using the default Xfree86 drivers, which are not 3D accelerated (I think).. I had a ATI Rage 128 Pro until last month at home, (running in WXP though, I hadn't time to test it in Linux), and the performance was good too (in my own reference frame ). 2K textures only, of course

Plz, Rei, post your OpenGL info (as shown in Celestia), and your glxinfo.

PS: *good* graphics card is very relative here!! If you don't own at least a GeForce2 32M, you have a *bad* card by our standards!! I have *very bad* cards, and I expect to afford a better one when my new skiing apartment stops eating all my extra cash...

Thank you everyone. Just knowing that other people weren't getting these problems prompted me to run some tests, and apparently *neither* of my computers had hardware GL acceleration working. That'll do it every time Now I can enjoy the beauty of Celestia at high FPS, huzzah!

Hmm, I wonder if I can now use .dds files...

Thanks!!!

Rei wrote:Thank you everyone. Just knowing that other people weren't getting these problems prompted me to run some tests, and apparently *neither* of my computers had hardware GL acceleration working. That'll do it every time Now I can enjoy the beauty of Celestia at high FPS, huzzah!

Hmm, I wonder if I can now use .dds files...

Thanks!!!

Yes and No;-)

At work (where everyone is supposed to work with anything but Celestia) you can. Too bad...

At home (due to your ancient ATI card) you cannot...
Here you will also experience rather reduced display features, unfortunately.

Bye Fridger

t00fri wrote:(where everyone is supposed to work with anything but Celestia)

I disagree!! It depends on what your work is. Celestia is perfect for teaching science and astronomy. So you can run rightfully at your work if you are an astronomy teacher...


Or perhaps if you are learning/teaching OpenGL?

Actually, I was killing time, waiting for an assignment, which I finally got. So no more Celestia for me here

BTW, an option to change the polygon count still would be very nice.

jamarsa wrote:

t00fri wrote:(where everyone is supposed to work with anything but Celestia)

I disagree!! It depends on what your work is. Celestia is perfect for teaching science and astronomy. So you can run rightfully at your work if you are an astronomy teacher...


Or perhaps if you are learning/teaching OpenGL?

Wait...my statement referred to Rei and her Geforce2 MX card. Not to people in general;-). I am having quite some suspicion that Rei is NEITHER an astronomy or science teacher NOR teaching OpenGL...

Bye Fridger