Celestia Forums

I don't understant how Celestia handles really big textures. I installed a Blue Marble map to see Venice at level 10.
When I zoom the pc (a centrino 1400 with 512 mb of ram) starts swapping as hell and almost freezes. It seems that the program is loading the ENTIRE set of textures of the current level, instead of the small portion that should appear on the screen. Zooming in does not help: everything freezes again for ages and only at the end the program works normally.
Is it the way the program is designed to work?

Another question: is it possible to use textures beyond level 10?

As I understand it, you need three things to handling big textures - a graphics card with a LOT of memory, a lot of motherboard RAM, and a big hard drive to hold the textures on. And a fast CPU helps, obviously.

So if things are getting all jerky, it's likely that you're lacking in one of those departments. You probably need at least 1 GB of RAM for starters, and you need a graphics card with at least 128 or 256 MB of RAM. Otherwise I'm afraid you may just have to make do with lower resolution textures.

Heck, I have a 3.8Ghz P4, 2GB of RAM and a 256MB graphics card and it can still stutter in spots when I zoom in and move around using 32K textures

Suskis,

What do you mean when you say huge textures ?
A lot of close-up textures are in DDS format, so, Celestia can handles them well enough with only (on my PC) a very short hiccup the first time it loads the textures.

If you use the last Celestia version 1.4.0pre6 you can use levels 11 and 12.

jdou

jdou wrote:Suskis,

What do you mean when you say huge textures ?
A lot of close-up textures are in DDS format, so, Celestia can handles them well enough with only (on my PC) a very short hiccup the first time it loads the textures.

If you use the last Celestia version 1.4.0pre6 you can use levels 11 and 12.

jdou

I mean, for example, a full blue marble set. But since venice was in jpeg, I downloaded the jpeg version of blue marble too. I should have used the DDS instead?
Also: where can I download level 11 and 12 textures?

Using DDS gives a big improvement - you'll get rid of the JPEG-uncompression, DDS-compression steps for every tile.
More improvements can be made if you put Celestia textures on your raid stripe set partition. This way harddisk read speed is about doubled.

maxim

maxim wrote:Using DDS gives a big improvement - you'll get rid of the JPEG-uncompression, DDS-compression steps for every tile.
More improvements can be made if you put Celestia textures on your raid stripe set partition. This way harddisk read speed is about doubled.

maxim

But still do not understand why it takes so long: does it really Celestia loads the FULL set for a certain level instead of the small part you see on the screen? I mean: if I am looking at Italy, there's no point in loading Japan. I hope this is the way Celestia works.. But its slowness makes me think the opposite...

It only loads the part you see.
But if you look towards the horizon, this may be several tiles that simply appear as almost a line.

maxim

hi i am on a old pen 4 and a old nivida gforce 2 mx 64 and 512meg ram
and have no problem with my 64k earth

it sounds as if you have the vt set up wrong and you are tring to loade vis.earth 32k map and not the vt's

With a Geforce 2mx????

I have a Geforce 4mx (with also 64 MB) - Can you please write which (i hope it will be written so) texture (for earth) you have in usage?

I've big problems with 16384*8192 textures.....

thanks

rifl

maxim wrote:More improvements can be made if you put Celestia textures on your raid stripe set partition.

what is -raid stripe-?

RAID = Redundant Array of Independant Disks
It's the use of multiple disks configured as if they were a single disk. It can be done using special hardware or using software. It usually is done for reliability: one or more disk drives can fail and all the data is still available.

Striping = placing each sequential disk block on a different disk drive. This is also called RAID 0. It's usually done for performance.

If you stripe across 4 disks, for example, disk 1 gets block 1, disk 2 gets block 2, disk 3 gets block 3 and disk 4 gets block 4. If the disks' rotations are synchronized, you can read all 4 blocks in at the same time, in the same amount of time you would read one block from one disk. In other words, you'd get 4x the data rate of a single drive.

Unfortunately, most ATA disks are not synchronized, so striping usually doesn't provide any performance gain unless you use really large disk blocks.

RAID 1, also called "mirroring', consists of writing exactly the same data to two or more disks. This gives more reliability, since either disk can fail and you'd still have all your data. It gives better input performance than a single disk, since data is read from whichever of the two disks happens to have it ready first. Writing is slower than to a single disk, since it isn't finished until the second, slower, disk has been written to.

A combination of RAID 0 and RAID 1 (usually called RAID 0+1) normally uses 4 disks: stripe across two, mirror them on two others. It can provide the advantages of both.

The other common RAID configuration, RAID 5, spreads the data over several disks and has an additional parity drive to verify the data. Any one disk can fail and all the data will still be available.

With a Geforce 2mx????

I have a Geforce 4mx (with also 64 MB) - Can you please write which (i hope it will be written so) texture (for earth) you have in usage?

I've big problems with 16384*8192 textures.....

-------------------------
Does anybody know somethin about that ? a 64k texture with a geforce 2 MX??

thanks

rifl

i still think you have earth set up as a single map and not a virtual texture

dose your file with the textures look like this

or are you loading a single 16k x 8k map
on my sys a 16384x8192.png will take 2 min. to load

i am using a 32768x16384.png virtual tex.
ie. level0 to level5

hi john, can you give me a link to your texture? and this one runs liquid?

It took me 15 min to load my 16384*8192 px texture... (jpg) it was terrrible slow.....

whats with the texture on http://www.celestiamotherlode.net/catalog/earth.php
--> 64K Jestr Earth Mark II (VT/DDS)

Which texture on this site should i use when non of these - can you give me a link to the other please?

thanks, rifl

Earth ---this is a link to my earth virtual texture----
http://johnscelestiapage.no-ip.com/VirtualTextures/filemgmt/viewcat.php?cid=7

and to my 8,4k earth map


http://johnscelestiapage.no-ip.com/filemgmt/viewcat.php?cid=2