No rings for Saturn!

[rthorvald]

Problem: Rings won??t show, or is just a featureless dark gray.
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I have just installed Celestia on an imac G5. The graphics card is Nvidia GeForce FX 5200, 64 MB VRAM. The rest: 1GB RAM /18ghz/OSX 10.3.5.

I believe the machine use OpenGL 1.4 (info on this is very difficult to find, but i know my Powerbook running 10.3.5 uses 1.4, so i assume the same is true here). The GeForce Extiension has Vno. 1.3.28.

I am reluctant to update OSX to 10.3.7. because it seems less stable than 10.3.5.

Everything works fine, exept for jovian rings: these are more or less invisible. Ring shadows shows up, though.

The default rendering path is NV C+ARB VP. Rings will [b]only|/b] show correctly if i use the Multitexture path...

Now, Apple always incorporates the graphics card updates with it??s own software update - it seems impossible to get directly.

Question is, do anyone else see similar problems? Suggestions to fix it?

rthorvald

[Tetzauh]

They are supossed to be nearly invisible. As oppsed to saturn, the Jovian rings are really faint. The Voyager saw them on it's way out of the Jovian system, glowing faintly on the sun. If you look at a picture of jupiter you won't see rings, unless it's purposely overexposed to see them.

[rthorvald]

They are supossed to be nearly invisible. As oppsed to saturn, the Jovian rings are really faint.

Sorry, i was a little unclear here; i used jovian rings as a general term:
rings around jovian-type planets. The problem goes for ALL rings;
Saturn??s rings ought to look like the left image below, but on the imac,
it looks like the image on the right:


-rthorvald

[maxim]

One possible cause could be a small texture memory buffer.
Your horizontal ring texure size should not excert the texture memory size.

maxim

[rthorvald]

One possible cause could be a small texture memory buffer

How do i determine that?
Other files, far bigger, shows up just fine. The problem is limited to rings only - all rings, in all planetary systems that has them. Also, if i use the "multitexture" render path, the rings shows up fine. And on Saturn, i don??t have *anything* else enabled.


-rthorvald

[maxim]

Ring textures - like DSO textures - are limited to the actual texture buffer size of your graphics card. That means with a 2k buffer size you can only use DSO or ring textures up to 2k. Ring textures are blown up vertically, so even if you have only one line, it's horizontal size in pixels is the limit. Tha could be irritating when looking at the file sizes. Celestia info should show your texture buffer size.

But if you could show up rings fine with 'multitexture' setting, the upper cause seems to be unlikely. Not shure what else it could be.

maxim

[John Van Vliet]

if they are my rings then they are about 98% trans.
and very faint
look at jupiter from a bit below the equater and look up to the north pole and you will see them agensed jupiter's clouds

[Frank Hunter]

I too have an G5 iMac, same specs except:-

The GeForce Extension has Vno. 1.3.36
OpenGL driver monitor 1.0
OpenGL profiler 2.0
OpenGL Shade builder 1.1.5
Find in System Profile/Software/applications

Don't know much about Open GL and grasping at straws but could it be a faulty OpenGL Shade builder?

I am having no problems with Saturns rings but, on a quick search, can't see Jupiter's.

Frank