Problems with Specular Reflections

isodextim · Post #1by **isodextim** » 27.10.2002, 17:25

I am a new forum member but have been using Celestia on and off for over a year now and although I have read past posts on the problems of Specular
reflecitions I was wanting some help.

This is the Graphic card I have
NVIDIA
8 MB OF SDRAM
128 bits graphic power
Software Version 4.0

Can anyone help me fiqure out why the Earth hasn't any sperical reflection?

Or is my graphic card not able to do this?

Tim

billybob884 · Post #2by **billybob884** » 27.10.2002, 17:36

isodextim wrote:Can anyone help me fiqure out why the Earth hasn't any sperical reflection?

what is sperical reflection?

isodextim · Post #3by **isodextim** » 27.10.2002, 17:53

Sorry Used the Astronomical term:
The sun-glint off the oceans when viewing earth from space.

Here I guess it is Specular texture?

Post #4by **selden** » 27.10.2002, 19:00

Tim,

You need to be more specific when describing your graphics card. There are many different models of cards using different chipsets from Nvidia.

At any rate, to see specular reflections, you need to turn on both the "pixel shader" and "vertex shader" options in Celestia's Render menu. If either or both of them are greyed out, then your card doesn't support the options that Celestia needs in order to display specular reflections.

I hope this clarifies things a little.

isodextim · Post #5by **isodextim** » 27.10.2002, 19:05

It does clear things up alot
They are both grey out.
Well thanks anyway Selden,
I'll stop trying.

Tim

erostosthenes · Post #6by **erostosthenes** » 27.10.2002, 19:45

don't worry if they're greyed out. mine were, too. but hitting ctrl+p and ctrl+v turn them on anyway.

billybob884 · Post #7by **billybob884** » 27.10.2002, 23:32

i'm having the same problem. gforce 2, 128 ram, 32 mb video card, anything else needed?

Post #8by **selden** » 28.10.2002, 02:32

Mike and Tim,

If erostosthenes' suggestion of trying the Control-P and Control-V commands doesn't work for your card, and if specular reflections are really important to you, then you need to conskder getting a different graphics card. Chris has written several times that he's hoping to be able to include some more generic support, but at the moment specular reflections are only available with some models of Nvidia cards. Unfortunately, however, he's still depemdant on the card manufacturers supplying OpenGL libraries that include the necessary functionality. My impression is that pixel and vertex shaders have to be in the hardware.

I know that specular reflections are visible if you have an Nvidia GeForec4 Ti 4xxx series card (4200, 4400, or 4600 -- I have a 4200). Others will have to tell you what other cards work.

Sorry.

billybob884 · Post #9by **billybob884** » 28.10.2002, 03:43

I tried the Ctrl V and P and it worked. thanks! One more question, I copied the ocean color onto a custom made planet but I only see the reflection on the earth.

erostosthenes · Post #10by **erostosthenes** » 28.10.2002, 06:19

the colour is not what determines specularity. either the texture has a specular channel built in, or you have to use a seperate specular texture where reflectivity is given by levels of whiteness (i.e. white oceans, black land, and i like to have greyish ice).

isodextim · Post #11by **isodextim** » 28.10.2002, 23:14

No the Cntrol+p or V doesn't work on my computer.
No big deal not that important just wanted to make sure I was
doing all I could to get the reflections.

THANKS ANYWAY

Tim

Don. Edwards · Post #12by **Don. Edwards** » 29.10.2002, 05:39

Well I have been able to use my lowly GeForce2 MX200 32meg to generate specturals. I think with only 8megs of VRAM he probably has a Riva-TNT or TNT-Vanta based card. These are not going to generate any specturals.
Specturals on GeForcce2 based cards are done in software mode while GeForce4 does this in hardware mode and I think GeForce3 does it this way as well.

fpolo · Post #13by **fpolo** » 01.11.2002, 21:29

isodextim wrote:Can anyone help me fiqure out why the Earth hasn't any sperical reflection?
Or is my graphic card not able to do this?

I've got a graphics card like yours (NVidia Vanta 8 MB).
There's a similar shareware program featuring ocean specular reflections, cloud shadows and other atmospheric effects, and all that things WORK on my graphics card while Celestia doesn't. It is called StarStrider 2.0 (http://www.starstrider.com/).

Try it, it is a nice program, though less intuitive than Celestia, and lacking of several features Celestia includes.