Is it true? Celestia can view Nebula????

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fsgregs
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Is it true? Celestia can view Nebula????

Post #1by fsgregs » 28.12.2002, 01:53

In reading some of the forum posts, I've discovered references to "nebula" that Celestia may be able to see (e.g. - see recent post on FOV's). Is this true? Has someone placed some actual nebula in the sky somewhere that Celestia can see? If so, PLEASE tell me where to download those beautiful nebula(s) ......
:roll:

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Post #2by bh » 28.12.2002, 11:15

fsgregs

Follow the thread in Celestia Developement - NGC 1999 system.

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Post #3by Redfish » 29.12.2002, 14:33

No it's not possible. Cuz we don't know the 3d composition of nebulae. Therefor it's impossible to do anything else than put an image somewhere in the sky.

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Post #4by Darkmiss » 30.12.2002, 23:10

here is a picture of one that Rassilion made

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Post #5by Redfish » 30.12.2002, 23:57

So what does it look like when you fly some 3 LY to the left?

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Post #6by selden » 31.12.2002, 02:00

It disappears, of course.
But that's because of a design limitation in the current version of Celestia. Large extended objects really aren't supported well. But I'm sure that'll be fixed Real Soon Now ;)

And your implication is right, too: Ras' did choose to make a "billboard" object.

Nevertheless, extended 3D objects are important. While we can't actually know their visual appearances except as they're seen from the solar system, the depths of many nebula have been estimated in various ways.

One reason for including nebulas, if only in billboard form, is being able to show why stars can't be seen in various directoins. As it is, the "spokes" are rather strange.

Besides, they look pretty!
Selden

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Post #7by Darkmiss » 31.12.2002, 02:49

Hey who can argue when we have sight like this in Celestia now
This is surounding my star wars universe at the moment

I just hope Ras makes some more shapes, sizes, and colours 8)
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Post #8by Rassilon » 31.12.2002, 03:42

The billboard effect will be worked on for future versions...
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Post #9by Guest » 31.12.2002, 13:06

Redfish wrote :

No it's not possible. Cuz we don't know the 3d composition of nebulae.


So ? Make it up ! Doesn't matter as long as it looks right from Earth's point of view. Although how you'd actually make a volumetric nebula, I don't know. Maybe with particles or something...

(Mad Boris)

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Post #10by Redfish » 01.01.2003, 15:47

Anonymous wrote:Redfish wrote :

No it's not possible. Cuz we don't know the 3d composition of nebulae.

So ? Make it up ! Doesn't matter as long as it looks right from Earth's point of view. Although how you'd actually make a volumetric nebula, I don't know. Maybe with particles or something...

(Mad Boris)


Yeah sure make it up. But the same goes for the galaxies. You could make up the stars and render en entire galaxy with random stars, but at the moment i don't think it's possible. That's why no one has done it.
For stars i wouldn't mind randomly created stars, i'm not going to visit them all. And only the very close stars are nice to visit, but they all look the same at the moment.

Nebulae are a different thing. First of all look at the way the galaxy is rendered now with the blobby haze. Well if you would use that to render nebulae it would look very crappy. So that's not an option. Using images can be done but you'd get the same effect as in doom 1 :) no matter how you were facing an object it would always look the same. So the only option would be real 3d objects, but then we have the problem that we don't know the real 3d structure of the nubula.
One could make up a 3d model and put some transparent texture on it, and fill it with some particles that would be nice i guess. but who will do it? :)

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Post #11by Rassilon » 01.01.2003, 16:47

Actually the best option would be for chris to incoperate volume effects from studio max into Celestia then the nebulas would look realistic....I am unsure if volume effects can be exported to 3ds though....so this may not be an option....but if it can...it can be used with the mesh to produce the best results!
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arneB

nebulae

Post #12by arneB » 06.01.2003, 17:26

There is a program called SkyWorks (with downloadable sourcecode)
which renders beautiful volumertic and shaded clouds in realtime.
The clouds are particle-based, and I imagine the technique (using impostors) would be perfect for nebulaes. And it is very fast.
Download a demo or the sourcecode at http://www.cs.unc.edu/~harrism/SkyWorks/


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