Celestia Forums

Well I guess I had to do it. So heres the link to
" - Earth Central For Celestia -"
http://63.224.48.65/~impulse/Earth_Cent ... ntral.html

I did a small update to the 8k texture package. I added a new 8k bumpmap. I will be making it available as a seperate download so don't rush to download the whole package just to update for the bumpmap.
other interesting info in there as well.

Excelent

Extremely well done, it looks great and matches your mars page prefectly.
I really like the style and layout of these pages.
It would be great to see a central news page that linked to each planet page.

(whipcrack sound) am i too demanding


-

Hmmm,
- Don's Celestia Central Hub -
Has I nice ring to it.
Actualy I was thinking of a hub page earlier today. So thats next I guess.

Don.

Don, why don't you separate Earth specular map from the base texture. Then you can compress the base texture with dxt1 instead of dxt3. You will get twice smaller(and faster) dds file. Also then you can use lower res separate specular map in dds format also.
Celestia supports separate specularmap textures. I think it was "SpecularMap" in ssc file.

Not entirely true. I have played with it and sure the main texture gets smaller but then I have to add another .dds texture to the zip and that takes the size back up some. And don't even get me started on normalmaps.
I do plan on dividing them but I just haven't got around to it yet. The other reason I added the specmap in to the texture was for easier use and installing for beginers but as things have progressed that isn't as much an issue anymore. But as I said as soon as the NASA project is over I will start to get back to organising things better.

Don.

Don:
i didnt understand something, if i install your earth texture, i dont have to use a separate secular map???

ElPelado wrote:Don:
i didnt understand something, if i install your earth texture, i dont have to use a separate secular map???

ElPelado,

In Don's textures (DXT3) the specular map is built in the main texture as an alpha channel, so you don't need to use an external file. This is an advantage if you take in acount that you don't have to modify ssc files and burn your graphic card with extra work.

praesepe, thanks.
after a post the replay, u tryed it and it worked. and it works a little bit faster than with two different textures.

ElPelado wrote:praesepe, thanks.
after a post the replay, u tryed it and it worked. and it works a little bit faster than with two different textures.

The whole idea of using a separate spec file is that you may use a much worse resolution for it than for the main texture, which saves /a lot/ for people with old graphics cards like myself. If you got 128 MB you can clearly do whatever you please.

Bye Fridger

i have a 64Mb Nvidia GeForce 2. i know its not the best, but its enough for me

True, except when you try the extended star data base then it takes a minute for the card to catch up.. Other than that, it is awesome having a 128MB card

t00fri wrote:

ElPelado wrote:praesepe, thanks.
after a post the replay, u tryed it and it worked. and it works a little bit faster than with two different textures.

The whole idea of using a separate spec file is that you may use a much worse resolution for it than for the main texture, which saves /a lot/ for people with old graphics cards like myself. If you got 128 MB you can clearly do whatever you please.

Bye Fridger

Hi Fridger,

I want to address one old issue. It is dxt1a format. Isn't it the best format for keeping colors plus 1bit for alpha/specular? Specular map for planets is essentially 1 bit, not 8 as present. dxt3 or separate dxt1 specular map is obvious waste of resources. Of course using separate low-res specular map is usefull option and it must remain, but i want to be able to use dxt1a format also.
But using dxt1a produces strange efects in Celestia. I think the problem is within pixel shader part. Bacause you have a glimpse over Celestia sources can you explain what is happening. Chris?

Pixel wrote:

t00fri wrote:

ElPelado wrote:praesepe, thanks.
after a post the replay, u tryed it and it worked. and it works a little bit faster than with two different textures.

The whole idea of using a separate spec file is that you may use a much worse resolution for it than for the main texture, which saves /a lot/ for people with old graphics cards like myself. If you got 128 MB you can clearly do whatever you please.

Bye Fridger

Hi Fridger,

I want to address one old issue. It is dxt1a format. Isn't it the best format for keeping colors plus 1bit for alpha/specular? Specular map for planets is essentially 1 bit, not 8 as present. dxt3 or separate dxt1 specular map is obvious waste of resources. Of course using separate low-res specular map is usefull option and it must remain, but i want to be able to use dxt1a format also.
But using dxt1a produces strange efects in Celestia. I think the problem is within pixel shader part. Bacause you have a glimpse over Celestia sources can you explain what is happening. Chris?

Hey Pixel,

I agree with you, this also bugs me from time to time. This is a question for our OpenGL guru;-)

Bye Fridger

Pixel wrote:I want to address one old issue. It is dxt1a format. Isn't it the best format for keeping colors plus 1bit for alpha/specular? Specular map for planets is essentially 1 bit, not 8 as present. dxt3 or separate dxt1 specular map is obvious waste of resources. Of course using separate low-res specular map is usefull option and it must remain, but i want to be able to use dxt1a format also.
But using dxt1a produces strange efects in Celestia. I think the problem is within pixel shader part. Bacause you have a glimpse over Celestia sources can you explain what is happening. Chris?

DXT1a will not work . . . There is no real alpha channel in a DXT1a texture. One color in each 4x4 compressed block is defined to be transparent . . . This 'color key' transparency is different than having a one-bit alpha channel, because the transparent areas of the texture have no color (or, they all have the same color.)

--Chris