Celestia Forums

Hi. I'am new here and my english isn't very good, sorry. First: I didn't see the moderator's name before, so I selected my Username not very well...
I hope, I can change it, if it's necessary....

Creating a scale earth and moon in cinema4d I found Celestia. All my work is to be done there! Wonderful! And for free...

Thats my question:
Generating a movie by using the ISS flying over the surface of earth, I loaded the hires textures "Jestr Earth Mark I/II" with night and clouds. Its all fine. Very well texture! But if I select the ISS which is close to the surface (of course!), the zoom begins, my pc displays only black and celestia shut down at last. In the task-manager I see 1,8 GB memory used. Often (after a new starting celestia) the ISS covers a distance for hours, breaks into night - the same procedure happens....the memory grows up continuously and Celestia shut down!
I think my equipment isn't so bad. 2 GB RAM and windows XP and 256 MB on my craphics card are more than enough? And it's not the biggest texture yet!
It's possible to show this big surfaces as well as the less ones?
And whats about the hires surfaces of mars, mercury, the moons and galaxies?
I should like to import these in addition to!
If I leave a particular scene: why celestia don't clear the memory for new ones? I would rather wait for loading, its better than a shut-down!

Thanks for help!

Seldon (from Asimovs "Hari Seldon" of course)

Seldon,

People often misspell my name that way, so readers are just going to have to learn to recognize the difference between an E and an O

Virtual textures are the equivalent of gigantic surface texture images. Remember that a complete level 6 is equivalent to an 8GB image. Some arithmetic would be required to determine how much of the texture will be in the field of view from the altitude of the ISS.

Be sure to use a VT based on DDS images. They'll use the least memory.

You can limit the VT resolution by renaming the level directories that you don't want loaded from something like "level6" to "notlevel6".

Celestia does not delete the pieces of a VT from memory after they've passed out of the field of view, so Celestia will continue to grow as you view more of the texture.

Also, Celestia v1.4.1 loads more of a VT's tiles than is necessary. If you haven't already done so, I'd suggest trying again using the latest prerelease of Celestia v1.5.0, which loads fewer tiles (or recompiling from the current CVS code.)

You also should preallocate a virtual memory paging file which is at least large enough to contain Celestia and all of the other programs that are loaded into memory: at least 4GB. The operating system will not be happy if it runs out of page-file space. Windows will run faster if the paging file is contiguous, so be sure to defragment the system disk.

Another problem is that Celestia's executable is linked as a 32bit application under Windows, so it can't address more than 2 or 3 GB without being rebuilt as a 64 bit application. I don't know if anyone has managed to do that yet. Some changes to the source code might be required. The standard version of XP is limited to 32 bit addressing, anyhow.

I hope these comments help a little.

You can limit the VT resolution by renaming the level directories that you don't want loaded from something like "level6" to "notlevel6".

Yes, I have done this (deleting the last levels) and its better.
Thanks. If the texture is made of one piece, I would reduce it in a paint program. More than 30 MB is not expedient and You can't see it later.

My Paging File is big enough, so the problem is the limit of 2GB virtuell adress room (XP 32 bit). It's the same in Cinema4d - a very large scene could not be rendered.

Foremost I will delete all unnecessary objects, planets and textures from the "extra" folder, so they won't be loaded by Celestia....

Seldon

Seldon wrote:Thanks. If the texture is made of one piece, I would reduce it in a paint program. More than 30 MB is not expedient and You can't see it later.

That's what you're doing by eliminating the higher-resolution folders. Eliminating level 6 (and above) is equivalent to reducing the texture image from 64Kx32K (8GB) to 32Kx16K (2GB). Of course, since you're only looking at the path under the ISS, the entire texture isn't being loaded.

Foremost I will delete all unnecessary objects, planets and textures from the "extra" folder, so they won't be loaded by Celestia....

That should help, too.

selden wrote:Be sure to use a VT based on DDS images. They'll use the least memory.

All of my VT's are JPG. Some of them I've converted to that from PNG, because PNG files are rather large, and my hard drive space is rather limited. Furthermore, it takes longer for my computer to load PNG files in Celestia, and it zaps the speed severely. My computers basically paralyzes.

Is it possible to convert JPG to DDS? (This is probably a newby question, lol).

I've opened the file, Save As -> tx_x_y.dds. My computer still recognized it as JPG though.

You can use Irfanview or other utilities to convert between formats. There also are Photoshop plugins that can be used.

It's best to do all your artistic work with non-lossy formats, though. Generating a DDS (or JPEG) texture image file should be the very last step, since both of those formats throw away resolution in order to minimize the file size. Converting from JPEG to DDS makes image quality even worse.

A utility like NVIDIA's NVDXT is slow but gives good control over the details of the output file. DDS/DXT format has many options that Irfanview doesn't provide.

http://developer.nvidia.com/object/nv_t ... tools.html

Computer only recognises 1GB instead of 2GB RAM? I have just tried installing two sticks of 1GB RAM each but as I start the computer, it only recognises 1GB. I tried installing just the 1 stick and it then only recognises 512MB instead of the full 1GB.
______________________
[userid banned, advertisement removed by Selden]

salvadori,

Your symptoms are consistent with damaged hardware, most likely the memory stick which seems too small.

When handling computer components, you *must* use an anti-static strap connected to the metal of the computer case. Static electricity sparks that you cannot feel or see will cause permanent damage to the electronics.

My personal experience is that memory from different manufacturers often will not work together even when they have identical specifications.

--- edit ---

selden wrote:You can use Irfanview or other utilities to convert between formats. There also are Photoshop plugins that can be used.

It's best to do all your artistic work with non-lossy formats, though. Generating a DDS (or JPEG) texture image file should be the very last step, since both of those formats throw away resolution in order to minimize the file size. Converting from JPEG to DDS makes image quality even worse.

A utility like NVIDIA's NVDXT is slow but gives good control over the details of the output file. DDS/DXT format has many options that Irfanview doesn't provide.

http://developer.nvidia.com/object/nv_t ... tools.html

My F-TexTools 2.0/nmtools 2.0 produce directly highest quality DDS / DDSnm output based on the much superior squish algorithm (New OpenSource NVIDIA Texture Tools 2.05/2.06 !). My tools produce single textures e.g. from PNG input or VT's of course. They are designed to work for all OS, not just Windows!

@Selden,

any reasons why you systematically ignore these tools in your recommendation, although they definitely produce the best quality results and for VTs include all known optimizations? For example, Hungry has recently succeeded to make 64k Moon VTs with my F-TexTools ...

When recommending the meager DDS plugin of IrfanView, you definitely don't seem to be aware that the resulting DDS quality is often quite miserable ... It actually can be be quantitatively measured, you know... (nvimgdiff tool)

Fridger

This is the first time I've seen a bot edit a previous post to add advertising. Very interesting!
I'll be removing the advertisement and banning the userid.

Fridger,

a) You seem to be doing a very good job of recommending your tools. I tend to recommend tools I've used. I do not create hires VTs and have never used your tools.
b) I trust you realize the previous posts in this thread are quite old. I might make different suggestions today.

Selden,

selden wrote:...
a) You seem to be doing a very good job of recommending your tools. I tend to recommend tools I've used. I do not create hires VTs and have never used your tools.

It is not my concern to increase the number of users for my tools by telling people about them! The latter just represent a service to the community. Nothing more. If I note one day that they are not sufficiently used anymore, I'll stop their further development right away. I have no problems here.

Since you spend lots of time giving all sorts of advice to others (much of which obviously comes from scanning web sites rather than from your own practical experience), it just appears a bit strange (or badly informed, if you prefer) that you never mentioned the F-TexTools/nmtools in the respective context ...Notably since they are dedicated mainly to Celestia users and have been extensively tested, benchmarked and further tuned by quite a number of experienced Celestians, like in particular Christophe Teyssier, DW, ChrisL, cartrite...

b) I trust you realize the previous posts in this thread are quite old. I might make different suggestions today.

Sorry I did indeed not realize that the previous posts were so old. But my remark included more general observations... Actually, my tools existed in the same form already in 2007, except for the direct DDS output.

Please note that my tools are not at all restricted to VTs. For example, they work excellently for making "one-piece" normalmaps of any size (including "monster" sizes), either in PNG or DXT output format, for rescaling a texture to nearest power-of-two size, for adding to a RGB base texture an alpha channel , holding an arbitrary grayscale spec texture etc. They can also be used as multi-OS converters for PNG-> DXT 1, 3, 5, nm with and without CUDA GPU support. Just to name some non-VT applications.

In all cases highest quality, speed and versatility are foreground features.

Fridger

--- edit ---