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color mismatch + mapping flicks

Posted: 08.02.2004, 20:14
by nreeany
Hi,

am a new user of Celestia and I find this software absolutely awesome...

I don't know if this is a bug but for any strange reason, the moon and mars have funny rainbow colors. The mapping is ok but the color goes from blue to pink thru yellow and green.
On earth I also have mapping flicks depending on how long I have been using Celestia, the earth mapping desappears and is replaced by a blue/red/green dots white layer.
I am using Celestia 1.3.1 on WXP on a Compaq Evo 2.4 Ghz with an Intel 82845G family graph card with 64 Mb mem, driver version 6.14.10.3751.

Any clue ?

The rest is ok. Except has any one an idea how to install the add-ons, I wanted to install earth 8Mb mapping from the texture foundry but it does not seems to work...

Thanks for the help.

Henry

Posted: 09.02.2004, 00:31
by selden
Henry,

Sadly, Intel's 3D graphics chips are some of the worst :(

The rainbow coloring is due to the bumpmaps, which are supposed to cause shadows and highlights to appear on the sides of mountain and crater slopes. Intel's OpenGL library simply doesn't handle them properly. Others have reported similar problems. One way to keep ths problem from appearing is to type a Ctrl-V, switching to Celestia's "Basic" rendering path, so Celestia doesn't try to draw bumpmaps or specular highlights.

Celestia supports up to 5 different "rendering paths", depending on the graphics hardware:
Basic, Multitexture, Nvidia combiners, OpenGL vertex programs, and vertex programs+combiners. The vertex programs are used to draw bumpmaps and specular (mirror-like) highlights.

My guess is that the delayed color changes on the Earth may be due either to Celestia trying to draw specular highlights on the oceans, or, worse, to the chips overheating. See if switching to Basic or Multitexture mode helps.

You also might try editing Celestia\celestia.cfg
Remove the # from in front of the line

Code: Select all

   # IgnoreGLExtensions [ "GL_ARB_vertex_program" ]


Do any of these help?

works

Posted: 09.02.2004, 22:25
by nreeany
Selden,

Thanks for your prompt reply

your suggestion worked, no more rainbowish moon and mars...

I was going to buy me a new graphic card anyway, any recommandations for bumpmapping and specular lights supporting models ?

Thanks for your help

Henry

Posted: 09.02.2004, 22:48
by selden
Henry,

The obvious choices are Nvidia GF4 Ti4200 or higher or FX5200 or higher, or
ATI Radeon 9500 or higher, all with 128MB or more of memory. I think the least expensive of these would be about US$ 85 or so. Be sure to get one with a fan and warrantee. eVGA has (quiet) fanless versions, but they tend to overheat unless your system has plenty of air flowing through it.

Posted: 23.05.2005, 00:25
by Angry Space Goat
I just upgraded my video card/chipset drivers and found myself with the same problem. I have an image of the occurence:

Image

Damn you, Intel. I wanted spec maps and bump maps.

Posted: 08.06.2005, 02:18
by TourqeGlare
Angry Space Goat wrote:I just upgraded my video card/chipset drivers and found myself with the same problem. I have an image of the occurence:

Image

Damn you, Intel. I wanted spec maps and bump maps.


I wouldent mind a toggleable texture programe that does tht!
Thats HORRABLY gay (no offence), but still VERY cool!!! :D

Posted: 08.06.2005, 10:05
by selden
An engineer at Intel has provided a code fix for Celestia. Hopefully it'll appear in a future version of the program.