Celestia Forums

Does anyone with programming knowledge think it might be possible to include several maps in one file? While working on some high-res textures last night I began to wonder if three or four textures could be included in a single RGB or RGBA file. Specular, Bump, Night and Cloud maps all seem to only require a single greyscale channel each so maybe it would be possible to assign each to one of the RGB(A) channels of a single file and have Celestia extract them as needed. This way we could have a fantastic-looking Earth with all the graphical bells and whistles that would fit in two DXT-compressed files. This way everyone would be able to get more bang for their graphics-card-buck. At the moment I'm using an 8k Earth without a specular channel (21MB DXT1c) plus an 8k Cloud map (27MB PNG) and it runs smoothly on my 32MB GF2 GTS card. However when I enable my 8k nightside texture (21MB DXT1c), things slow to a crawl. So what do people think, is something like this possible to achieve?

/me waits for the day when I can use all the 32x16k textures on my computer and still get full frame rate.

Ortolan wrote:/me waits for the day when I can use all the 32x16k textures on my computer and still get full frame rate.

Well, if you don't mind waiting 5-6 months and spending 400-500 dollars on a card, ATI and Matrox are both releasing 256 and 512 MB cards, and these cards also have performance that will put the GF4 TI 4600 to shame.

The ATI card should indeed be very fast, but the new Matrox Parhelia has somewhat disappointing performance. A Geforce4 Ti 4400 or 4600 will be faster for Celestia than any announced Matrox board. The surround gaming feature could be neat if you have three monitors.

--Chris

Hey Chris, Celestia doesn't need 200fps. I think 30 fps are enough for such application. What is more important from vid-cards are features - big frame buffer, multitexturing, volume texturing, displacement mapping!!, antialiasing... i am wrong ?

Besides Matrox has a history of being unreliable with some software out there...The higher video memory will be nice...but GF4 I think can go up to 512 megs...or am I dreaming?

I'm not sure that having all the different components in two files rather than three or four will reduce the memory requirements per se - you still have the same number of channels.

I've been wondering if it's possible to optimise the performance of Celestia. At most all mine has to display is a ball with a big texture on and a few effects - this should not stress an Athlon 1Ghz with a GeForce II Pro, yet it does.

I've yet to entirely pin down where the performance bottlenecks on my system are, but they're somewhere in the graphics card and in it's having to store or display several ridiculously big textures.

I think, that it's not only the textures but the high polygon count as well (i still remember openuniverse with planets of 32 slacks and slices ;))
although T&L should help there .. but im not sure wether it suffices to transform all these textures and still work on them with vertex&pixel shaders ...

Pixel wrote:Hey Chris, Celestia doesn't need 200fps. I think 30 fps are enough for such application. What is more important from vid-cards are features - big frame buffer, multitexturing, volume texturing, displacement mapping!!, antialiasing... i am wrong ?

Yess, but when you can get 200+ FPS with reflectivity, displacement mapping, and all that other stuff, it really IS good.

If you can get 200+ FPS with a 24k*16k texture, it's impressive.

The TI4600 is good, of course, but it can't do what the new ATI card can(however, there are rumors going around of a NVidia card that will have 512 or even 1 GB of RAM, and will top the performance of the new ATI card by almost 25 percent, but that's about 8-9 months away)

Look, if a card can run Doom 3 at max quality seamlessly(ATI's new card), then it should have NO problem with Celestia.

*drools at the thought of a triple-monitor setup, or even a 360 degree setup*