Missing eclipses

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Topic author
Fafers
Posts: 12
Joined: 18.09.2004
With us: 20 years 2 months
Location: Belo Horizonte, Brazil

Missing eclipses

Post #1by Fafers » 18.09.2004, 21:32

Greetings from Brazil,

First of all, I apologize for my poor english...

Celestia is great! Congratulations for its creator and all the colaborators.

Now the question:

I've just upgraded from Celestia 1.3.1 to 1.3.2. I know that irregular bodies do not cast shadows on planets. But in Celestia 1.3.1, the planets did cast shadows on their irregular moons (like Jupiter's shadow in Amalthea, for example). They were not quite perfectly rendered but were fine to me. For my surprise, in Celestia 1.3.2 this does not happen (at least in my computer)! Repeating the example above, when Amalthea passes behind Jupiter, the irregular shaped moon was still iluminated by the sun, as if Jupiter was transparent (and I'm sure the option for showing eclipses was selected).
I need help here. Is it a bug or am I doing something wrong?

My system:
AMD 2.2GHz
512MB RAM
NVidia GeForce4 MX440-8X, 64MB DDR (no ring shadows... :cry: )

I look forward for your reply,
Thanks

Fafers

ajtribick
Developer
Posts: 1855
Joined: 11.08.2003
With us: 21 years 3 months

Post #2by ajtribick » 19.09.2004, 16:04

I also experience this problem... Amalthea is never shadowed by Jupiter

Celestia v1.3.2, Windows version (using WinXP Home), NVIDIA GeForce 3 Ti200 card

granthutchison
Developer
Posts: 1863
Joined: 21.11.2002
With us: 22 years

Post #3by granthutchison » 19.09.2004, 17:34

The eclipses for these objects were turned off some time ago, since they had become mysteriously badly behaved ... objects were turning emissive for no good reason. I presume Chris has so far been unable to find the bug.

Grant

chris
Site Admin
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Location: Seattle, Washington, USA

Post #4by chris » 19.09.2004, 18:07

Eclipses shadows on irregular objects never worked right as far as I know. I understand what needs to be done to make them work; these changes will be part of the work I do to enable bump, specular, and night textures for mesh objects.

--Chris

Topic author
Fafers
Posts: 12
Joined: 18.09.2004
With us: 20 years 2 months
Location: Belo Horizonte, Brazil

Post #5by Fafers » 21.09.2004, 03:36

Hi,

Thanks for your replies! :wink:

Chris,

I understand that they never worked right but in 1.3.1 there was, at least, some kind of shadow while in 1.3.2 there isn't any... :cry:
But it's ok! It's just a small detail in a great software. I'll wait for the upgrades.

bye!
Fafers

chris wrote:Eclipses shadows on irregular objects never worked right as far as I know. I understand what needs to be done to make them work; these changes will be part of the work I do to enable bump, specular, and night textures for mesh objects.

--Chris

Bob Hegwood
Posts: 1048
Joined: 19.10.2003
With us: 21 years 1 month
Location: Germantown, Ohio - USA

Post #6by Bob Hegwood » 22.09.2004, 21:17

Just thought I'd add my two cents worth concerning eclipse shadows...

Am still using 1.3.2 Pre11 and can no longer see eclipses on ANY of the
planets, regardless of which moon should be creating the eclipse shadow.

All I'm seeing now (via my Intel graphics chip) is a series of ugly, black
artifacts where the eclipse shadows should be.

Anything I should know about in order to correct the problem?

Cannot update my openGL drivers any further since Intel hasn't updated
them since 2002. Also experimented with turning on/off the Vertex Shaders
to no effect.

Any ideas?

Thanks, Bob
Bob Hegwood
Windows XP-SP2, 256Meg 1024x768 Resolution
Intel Celeron 1400 MHz CPU
Intel 82815 Graphics Controller
OpenGL Version: 1.1.2 - Build 4.13.01.3196
Celestia 1.4.0 Pre6 FT1

Bob Hegwood
Posts: 1048
Joined: 19.10.2003
With us: 21 years 1 month
Location: Germantown, Ohio - USA

Post #7by Bob Hegwood » 28.09.2004, 22:01

Another two cents worth for those who care...

As per Selden's advice (Thanks *very* much Mr. Ball!) I disabled my
Intel graphics accelerator chip and tried to view an eclipse shadow on the
Earth via Ulrich's - a.k.a Adirondack - Eclipse on Earth cel script.

Although I no longer see the stationary, ugly, triangular black artifacts
under the Windows OpenGL, I can *still* see no eclipse shadows
rendered on the Earth. I *do* manage to see some very faint cloud-type
dark shadows on the planet's surface, but the eclipses still do not work
correctly.

Just thought I'd mention it.

Thanks, Bob
Bob Hegwood

Windows XP-SP2, 256Meg 1024x768 Resolution

Intel Celeron 1400 MHz CPU

Intel 82815 Graphics Controller

OpenGL Version: 1.1.2 - Build 4.13.01.3196

Celestia 1.4.0 Pre6 FT1

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selden
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With us: 22 years 2 months
Location: NY, USA

Post #8by selden » 28.09.2004, 22:35

Below are the different types of shadows drawn by Celestia for the 2006 African solar eclipse when using Celestia's different "Render Paths" and an Nvidia FX5200 graphics card.

Although they do show that an eclipse is happening, I'm sorry to say that the shadows aren't all that great. Hopefully the imagry for all of the Paths will be improved in a future version of Celestia.

(Each of the thumbnails below links to a larger picture.)

Image
Basic Render Path


Image
Multitexture Render Path

Image
Nvidia Combiners Render Path

Image
OpenGL Vertex Program Render Path

Image
OpenGL + Nvidia Combiners Render Path

Image
Nvidia FX Render Path

System:
512MB 2.4GHz P4, WinXP Pro SP2
128MB FX5200, Forceware v61.76
Celestia v1.3.2 final
Selden


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