Ring casting shadow

AstroBoy · Post #1by **AstroBoy** » 22.06.2003, 15:23

I saw that rings can cast shadow onto the planet in selden's website, but I do not see that !!

http://www.lns.cornell.edu/~seb/celestia/iapetus-shadow.jpg

http://www.lns.cornell.edu/~seb/celestia/saturn-ringshadows.jpg

Does it requier a special add-on or is it a problem with my computer ?

I have Win2k with nVidia GeForce4 MX 440

Thanks for your help...

Post #2by **selden** » 22.06.2003, 17:00

1) make sure you have "ring shadows" selected in the "Render" "View Options" menu

2) Type "Control-V" several times to toggle among the "Render Path" optons to see which paths your graphics drivers support. To see shadows on the planet with Celestia v1.3.0 and later, your drivers need to support the "OpenGL Vertex Program"

3) See the Users' faq: Q1/A1 and Q2/A2

4) According to one post, many new features are available for the older cards in the latest Nvidia drivers . See http://63.224.48.65/forum/viewtopic.php?t=2598

5) the latest official Nvidia drivers, v44.03, can be downloadef from
http://www.nvidia.com/content/drivers/drivers.asp

5A) at least one Web site claims to have even more recent unofficial beta drivers which were "leaked". Caveat Emptor.

6) Although they're certified for the FX drivers, there seem to be bugs in 44.03 in the code for some older cards. They went into a CPU-bound loop on my system (GF4 Ti4200) shortly after rebooting. Windows XP complained bitterly. So did I

so I'm still using 43.45.

Does this help?

AstroBoy · Post #3by **AstroBoy** » 22.06.2003, 18:42

1) make sure you have "ring shadows" selected in the "Render" "View Options" menu

Yes, it is. When activate I can see planet shadow on the ring.

2) Type "Control-V" several times to toggle among the "Render Path" optons to see which paths your graphics drivers support. To see shadows on the planet with Celestia v1.3.0 and later, your drivers need to support the "OpenGL Vertex Program"

I tried CTRL+V, and celsetia toggle between :

They all work fine except for the "Basic" (Planet shadow on ring disapear) but no shadow on the planet.
I observe Saturn during a complet revolution to be sure to see a shadow casting if it is present.

5) the latest official Nvidia drivers, v44.03, can be downloadef from
http://www.nvidia.com/content/drivers/drivers.asp

Sorry, forgot to say that I use 44.03 drivers, but as I never seen those shadow before (with older version) I don't think that should be the origin of the problem.

So, still doesn't see anything :cry:

Darkmiss · Post #4by **Darkmiss** » 22.06.2003, 18:54

I thought i read here somwhere that the MX range of Graphics cards
do not suport this feature ?

Post #5by **selden** » 22.06.2003, 18:55

Well, I guess this is a problem for Chris Laurel to comment on.

If you feel like taking a chance, you might try the "unofficial drivers". A Google search for "nvidia drivers" finds them quickly. Be sure to do a full backup of your system disk first, though. For all I know they're really a "trojan horse" program.

Post #6by **selden** » 22.06.2003, 19:04

Paul,

My (apparently mistaken) understanding was that the ring shadows on the planet should be visible if the drivers support "ARB_vertex_programs". Apparently that's not quite enough, though.

Darkmiss · Post #7by **Darkmiss** » 22.06.2003, 19:24

yeah shame that really, he probably spent a whole lot of cash on that card too.
only to find out it doesn't do all that he wants.

Astroboy if you ever get the chance to get a G4 TI card with 128 meg on board, grab it, as it makes Celestia Fly...... :wink:

Post #8by **selden** » 22.06.2003, 20:14

Paul and Astroboy,

Like the MX series, the GF4 series is "obsolete" now. Since the FX series is starting to become available at reasonable prices, I'd suggest something like a 128MB FX 5200 to someone considering a middle-of-the-road upgrade these days.

At about U.S. $80, it's about the same performance as a 4200, but with more features for slightly less money. FWIW, some months ago, Chris "threatened" that he might add some new eye-candy features that'd only be visible on the FX series.

AstroBoy · Post #9by **AstroBoy** » 22.06.2003, 20:46

Well, as I see I have to live without it !! It's not an important feature, I think that I'll survive :wink:

FWIW, some months ago, Chris "threatened" that he might add some new eye-candy features that'd only be visible on the FX series.

Will there be picture post with those, just to see what I miss !!!

Evil Dr Ganymede · Post #10by **Evil Dr Ganymede** » 22.06.2003, 23:20

Hrm. I must have a really crap video card then (Powercolor Radeon 7500 (ATI clone), 64 MB RAM), because I only have two options when I press Ctrl+V - 'Basic' and 'Multitexture'.

Post #11by **selden** » 22.06.2003, 23:38

Dr Ganymede,

Unfortunately, my impression is that ATI isn't doing much to improve the OpenGL features available for their older cards.

According to a recent posting by Chris, if you want to stick with ATI, you'll need a 9500 or better to see all the features (about U.S. $125). (While they should work, there are serious bugs in the OpenGL libraries for the 8500 and 9000 cards that really mess up the ringed planets.)

Evil Dr Ganymede · Post #12by **Evil Dr Ganymede** » 23.06.2003, 02:45

Oh, I've no desire to stick to ATI if they're not up for the job.

I think I need a new video card anyway, I'm getting Lightwave 3D this week.

Are there any cards I should investigate that would be good, do you know? Apparently GeForce cards are good?

Post #13by **selden** » 23.06.2003, 11:41

It really depends on the application software and your budget.

Most of the professional 3D design packages (like AutoCad, Maya, and Lightwave) are certified to work only with specific cards and specific versions of their graphics drivers.

Several companies sell Lightwave packaged with particular graphics cards, like the Nvidia Quadro FX 1000. That card can be had for about U.S. $850. The Quadro FX 2000 is about $1400. I expect Celestia would work fine with either of those cards

My personal guess is that Lightwave will work OK with the consumer Nvidia FX 5200, too, although I've never used that software myself. The 5200 is only about U.S. $80 and has no problems showing all of Celestia's "eye candy."

Note that I haven't mentioned any particular manufacturer of the cards. Nvidia only supplies chips and "reference designs". Other companies actually make the cards, adding their own improvements. eVGA and Asus both have good reputations for their consumer cards. I'm sure there are others.

cal · Post #14by **cal** » 24.06.2003, 01:48

I have a Radeon 9100 and I found that if I use the Ctrl-V command and swith to "multitexture" mode, the ringed worlds are rendered properly.

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