Celestia Forums

will it run slower if i use virtual texture??
it seems difficult to install virtual texture

VT's can be somewhat difficult to install sometimes, especially if you are installing at VT that depends on another. But Celestia will run much faster since it only loads the piece of the texture, called the tile, that you are looking at, rather than the whole object.
Cheers,

Joe

thx.
But one more question,will the planets look more realistic if i use virtual texture??

cyf wrote:But one more question,will the planets look more realistic if i use virtual texture??

VTs allow much higher resolutions than regular textures, because only small parts of the texture have to be kept in memory. Typical VTs for Earth are 32768x16384 (or even 65536x32768) pixels in size.

Whether a planet looks more realistic depends on from where you are looking at it, and the quality of the texture. From far away the higher resolution of VTs isn't used, so the visual quality depends solely on the quality of the texture. When close to the surface VTs allow much better quality.

One thing about performance: the higher resolution and better general performance comes at a prize. Celestia has to load new tiles from disk when you change position above surface or distance. This will (depending on your system) be noticeable as a short pause.

Harald

Cyf...

I'm using a fairly non-graphics capable machine, and I can notice some really nice
advances in the textures of the planets using VT's. Since my system is only
capable of displaying a 1k image by itself, (1024x1024 pixels or less), virtual
textures which have been sliced into 512-byte pieces work really well on my
machine.

As Harry mentioned though, the trade-off is a bit of hesitation as you
move around the planet which is being displayed via a VT. These delays can
be anywhere from .5 seconds to 3 seconds, depending on what I'm trying to do.
Virtual textures are definitely worth using if you you don't already have a great
graphically-endowed machine to begin with though. Also, once you have them
installed, you don't have to use them if you are in a hurry. Just set them up as
alternate textures, and you can then right-click on the planet to either use the
Virtual Textures, or the normal - single - texture you already have.

If it would help, you can also download my "Virtual Textures For Dummies"
Guide. (The Dummy is me!) Just go to my website HERE and visit the
Miscellaneous Downloads page to get the Guide.

Hope that helps...

Take care, Bob

thanks for your help.
Now i have a better understanding about the virtual texture.
But where can i find the virtual texture to download??
any guildlines for me to follow??

Ah ha!
This is why I troll around the forum - so I can point newbies in the direction of my online catalog of (just about) everything Celestia. Just click on the "www" at the bottom of my post and you will be in VT heaven! Soon my army of black and white html pages will take over the world. I am a genius.

Joe

cyf wrote:thanks for your help.
Now i have a better understanding about the virtual texture.
But where can i find the virtual texture to download??
any guildlines for me to follow??

Cyf,

If you downloaded the VT's For Dummies package, there's already a set
of textures for use on Mars included in the package. Only up to level 3 if I recall
correctly, but I *did* include them in the package, along with instructions on how
to use them. Maybe you just downloaded the Manual?

At any rate, "Go to Joe's." He's got *lots* of neat stuff to work with there.

Take care, Bob

Thanks!!
I can install the Mars virtual texture successfully!!
thank you for your package,it is really useful for the starter
Amazing!!
The resolution of Mars is very high and my Geforce4MX440 card can run it smoothly.
For my Geforce4MX440 card,what is the maximum resolution can i use with a smooth motion?

cyf wrote:For my Geforce4MX440 card,what is the maximum resolution can i use with a smooth motion?

Cyf,

I have absolutely *no* idea. Remember, I'm still using my non-graphics
endowed machine. Maybe Selden would know? Remember too, that as you try to
use larger virtual textures, you rapidly begin to talk about a *lot* of images
which have to be shuffled around as you explore the planet(s). Just experiment
with some of the VT's which can be found at the sites on the Celestia Web Ring, and
at Joe's Place in particular. Hey, I like the sound of that... Joe's Place... Hmmm.
Much better than the current title.

Take care, Bob

cyf wrote:For my Geforce4MX440 card,what is the maximum resolution can i use with a smooth motion?

4k should still run smooth with a full planetary texture. 2k for deep space objects. The best VT resolution is 0.5k.

maxim