Using the Nmtools package

[woody]

Thanks cartrite & selden for yours links.

I studied the docs and wrote the .ctx & .ssc files that I place in the Celestia directory as follow :

C:\Program Files\Celestia\extras\gebco_bathy.ssc

Code: Select all

AltSurface "gebco_bathy" "Sol/Earth"
   {

   Texture "gebco_bathy.ctx"



C:\Program Files\Celestia\extras\gebco_bathy\textures\hires \gebco_bathy.ctx

Code: Select all

VirtualTexture
{
        ImageDirectory "gebco_bathy"
        BaseSplit 0
        TileSize 1024
        TileType "dxt5nm"
}



Then I copied the tiles folders there :

Celestia\extras\gebco_bathy\textures\hires\gebco_bathy\level0\*.dxt5nm
Celestia\extras\gebco_bathy\textures\hires\gebco_bathy\level1\*.dxt5nm
Celestia\extras\gebco_bathy\textures\hires\gebco_bathy\level2\*.dxt5nm
Celestia\extras\gebco_bathy\textures\hires\gebco_bathy\level3\*.dxt5nm
Celestia\extras\gebco_bathy\textures\hires\gebco_bathy\level4\*.dxt5nm
Celestia\extras\gebco_bathy\textures\hires\gebco_bathy\level5\*.dxt5nm

When I launch Celestia and right click on the Earth, I can see in the drop down menu my gebco_bathy texture.

If I choose it the surface of the Earth became totally WHITE

I guess something is missing somewhere. But what and where ?

Another question, is it possible to put those huge tiles folders out of Celestia directory, on another partition with more free space ?

Thanks again to share your knowledge with beginners.

Kind regards,

--
Woody

[cartrite]

To begin with I think you may have done the wrong file. The snowy alaska site seems to down right now so I can't verify that the file you used was a 16bit signed integer hieght map. That may have been a rgb texture map. The files you built with nmtools, if a correct file was used, would be a normal map and if no texture map was used the planet would look white but you should see shadows like the image I posted of mars. on page 16 of this thread. In that case you would also need a "diffuse" virtual texture of the earth as well. Search the BMNG site for whatever month you chose.
They have 12 maps.

cartrite

[t00fri]

Woody,

how about following carefully my tutorial in CelestialMatters??

http://www.celestialmatters.org/cm/host ... al00.shtml

Bye Fridger

[woody]

Hello,

I follow "exactly" the procedure described on the tutorial but with another file:
not the "world.200406.3x86400x43200.bin.gz", but with "gebco_bathy.21601x10801.bin.gz" (280 855 Ko) because I want to work on the ocean bathymetry.

It's probablly the reason why I failed: the dimension aren't the same ? I will have to adapt the code.

Could you help me?

The whole process took 4 hours on my venerable Athlon!

Regards,

--
Woody

[cartrite]

Do you see shadows on the white earth?
Is this file BMNG June? world.200406.3x86400x43200.bin.gz. You don't want to use that file anyway. If the file you used is from NOAA then it may be a good file if it's a 16 b bit signed integer file.

[woody]

Cartrite,

The Earth was totally white without any texture.

What about the localization of the tiles folder outside the Programs files directory ?

[t00fri]

[cartrite]

If you have a image editor open one of the files you created and examine it. You should see some topographic features on a lot of them. The 1024k ones for sure. Also type the "~" key while running Celestia to see what is getting loaded or what errors are occuring.

Fridger, The file he said he used sounds like it may be a height map that NOAA made available but I can't remember. It's been a long time since I used thier files.

[woody]

I worked on a wrong file and didn't took time to read some theory before playing with my machine and get asap the result.

Too impatient!

Tonight, I will try with srtm_ramp2.world.86400x43200.bin.gz and vtgen.bat.

Thanks again

--
Woody

[t00fri]

Fridger, The file he said he used sounds like it may be a height map that NOAA made available but I can't remember. It's been a long time since I used thier files.

Correct, that's why I erased my above post. In any case woody used the wrong file

Bye Fridger

[woody]

Hi Fridger (& cartrite),

I ran your vtgen.bat script on the "srtm_ramp2.world.86400x43200.bin.gz" all the night and this morning, I got a successful alert window on my screen. Pleasant wakening!

I copied the "Earth"folder and the "Earth.ssc" file to the "extra" directory in Celestia.

When I launch Celestia, the image of the Earth appear normaly. Then, I right-click on it, the program crashes.

Could it be a problem of video memory ? I have 128Mb on a Matrox Dual head, 2 Gb of RAM.

Do you have any idea.

Thanks again,

__
Woody

[woody]

I forgot to say that I run Celestia win32-1.5.0pre3

[t00fri]

woody,

the vtgen.bat script is not by me. I think it is by tech2000 (Anders). I am surprised that it takes soo much time! I have never examined that script... On my machine all normalmap VT's are generated within 20-30 minutes ONLY! What kind of computer do you have???

Matrox cards are often plaqued with problems...Usually the reason for crashes are buggy, old drivers. Do you use the latest available driver?

You see, Celestia really challenges the card drivers with OpenGL functions and extensions. Often they have never been adequately tested by their vendors...

With proper drivers you are NOT expected to have a problem. 128MB should be enough for working.

What VT tiles did you take as base texture and as specular texture?? It is certainly advisable to use VT's of similar resolution for ALL textures!!

Bye Fridger

[woody]

Hi Fridger,

I updated the Matrox driver yesterday; I have the last one.

But, what do you mean by "What VT tiles did you take as base texture and as specular texture"?

I again forgot this step I think.

Shame on me!

--
Woody

[t00fri]

Hi Fridger,

I updated the Matrox driver yesterday; I have the last one.

But, what do you mean by "What VT tiles did you take as base texture and as specular texture"?

I again forgot this step I think.

Shame on me!

--
Woody

Celestia works with an overlay of SEVERAL textures, each fulfilling a different purpose:

base texture: That's an (unshaded) (RGB) texture, responsible for rendering the colors of the surface

specular texture: It is responsible to tell the reflective (sea) and non-reflective (land) regions. Reflective=white, non-reflective=black. This has to do with the so-called "alpha channel".
In fact, in my latest tools, the base and spec textures are mounted together to form a RGBA texure. This saves card memory.

normalmap: This is what you did so far. See my tutorial for a summary of the purpose of normalmaps! normalmaps provide a "dynamical" shading of the surface, depending of the position of the light source (Sun!).

nightlights texture: This is a texture that carries the information from the city lights etc (on Earth).

Each one of these textures may be used as "one-piece" or as VT tiles. For larger textures > 8192 x 4096 pixels, say, it is advisable to cut the textures into VT=virtual texture tiles! Typically a tile size of 1024x1024 pixels is advisable.

So you need to get a hires set of VT tiles for the base, spec and nightlights. My new tools do this just like the nmtools for normalmaps, but I still want to do some further tests before their publication. You may download for now some VT's from the Motherlode (The user Fightspit has a 64k set)

Bye Fridger