Advanced lighting?

[StarStruckRabbit]

Are there plans for providing better quality lighting in Celestia? Don't get me wrong, it looks very nice right now, but wouldn't it be cool if Celestia had lens flare and such? (Just for eye candy sake.)

I know there are flare updates for stars available, but they're still just textures. What if Celestia had dynamic lens flare that changed and moved with the camera? Is there a way to do this? Is it something we can expect in upcoming releases of Celestia?

[ElChristou]

What Celestia show is supposed to be like naked eyes, so no lens flare simulated...

[Hungry4info]

Really?
When I look at the sun with my unaided eye, I see great irregular streaking arcs of light coming from it in all directions. The stars in Celestia have been demoralized over the past few releases to look like nothing more than white, dead spheres.

Is that how they actually look? If so, then I may be hypersensitive to light, and even the dead white ball of our sun looks blindingly bright.

Eh, maybe it's just me.

[dirkpitt]

Lens flare is not very realistic if the sensor viewing the scene is the human eye, but space probes use cameras so it might be realistic in that case.

[ElChristou]

We all agree the stars rendering is not good at this point but we will have to wait for Chris' work on HDR to see some more realistic rendering...

[dirkpitt]

Lens flare does not need to be synonymous with HDR, it could be pasted on to the current version of Celestia (LDR).

Off topic but speaking of HDR, a good HDR implementation that is also compatible with older graphics cards is really hard to do. I briefly experimented and immediately ran into problems with alpha blending not working in floating point buffers. I expect to see lots of breakage like what we're seeing right now with point sprites and depth sorting (at least on the Mac). Some discussion on how to manage backward compatibility for HDR is probably needed soon.

[ElChristou]

Lens flare does not need to be synonymous with HDR, it could be pasted on to the current version of Celestia (LDR).

Off topic but speaking of HDR, a good HDR implementation that is also compatible with older graphics cards is really hard to do. I briefly experimented and immediately ran into problems with alpha blending not working in floating point buffers. I expect to see lots of breakage like what we're seeing right now with point sprites and depth sorting (at least on the Mac). Some discussion on how to manage backward compatibility for HDR is probably needed soon.

I wasn't thinking in lens flare with HDR rendering, more in intense glare when the observer is close enough to a star...

As I see it (just like point sprite), HDR will be OGL 2 only, and of course for the last boards (less than 1 or 2 years I suppose)... I fear lots of people won't be able to enjoy those stuff, but...

[danielj]

I think you are WRONG.The majority of people in this forum have at least a Geforce 6(actually many have Geforce 7 and above).And you can??t delay any Celestia improvement just because it won??t be able to be used by Geforces FX or below.Some things HAVE to be exclusive of the newer cards.For example,Open GL 2.0 is exclusive for Geforces 6,7,8 and Radeon X and X1XX.Why can??t HDR be the same?

Lens flare does not need to be synonymous with HDR, it could be pasted on to the current version of Celestia (LDR).

Off topic but speaking of HDR, a good HDR implementation that is also compatible with older graphics cards is really hard to do. I briefly experimented and immediately ran into problems with alpha blending not working in floating point buffers. I expect to see lots of breakage like what we're seeing right now with point sprites and depth sorting (at least on the Mac). Some discussion on how to manage backward compatibility for HDR is probably needed soon.

I wasn't thinking in lens flare with HDR rendering, more in intense glare when the observer is close enough to a star...

As I see it (just like point sprite), HDR will be OGL 2 only, and of course for the last boards (less than 1 or 2 years I suppose)... I fear lots of people won't be able to enjoy those stuff, but...

[ElChristou]

I think you are WRONG.The majority of people in this forum have at least a Geforce 6(actually many have Geforce 7 and above).And you can??t delay any Celestia improvement just because it won??t be able to be used by Geforces FX or below.Some things HAVE to be exclusive of the newer cards.For example,Open GL 2.0 is exclusive for Geforces 6,7,8 and Radeon X and X1XX.Why can??t HDR be the same

Who say something will be delayed?

Anyway danielj, your comment is a bit misplaced because you are often the first in crying when something don't run on your (not to date) system...

[Boux]

As I see it (just like point sprite), HDR will be OGL 2 only, and of course for the last boards (less than 1 or 2 years I suppose)... I fear lots of people won't be able to enjoy those stuff, but...

Hmmm, point sprite rendering is nothing new. As far as I remember, this has been implemented since OGL 1.2.
It has been available long ago in Direct3D.
Nevertheless, any decent piece of 3d rendering sofware should be able to scale up/down with the detected hardware and driver capability.
So for once, danielj is right.

[ElChristou]

Hmmm, point sprite rendering is nothing new. As far as I remember, this has been implemented since OGL 1.2.
It has been available long ago in Direct3D.
Nevertheless, any decent piece of 3d rendering sofware should be able to scale up/down with the detected hardware and driver capability.
So for once, danielj is right.

You are probably right but the fact is that right now on a platform (osX), point sprites are still useless because of some driver issues. End users cannot no anything to solve this, so finally we can see that even an old feature can be problematic...

Now again, I wonder what can make danielj say that some stuff may be delayed... If I'm not wrong, I only stated that most eye candy feature will wait the HDR work, but eventually some would not be able to appreciate it...

Thinking about it, a good thing to do would be to have a little something on the main site to inform people about the issues concerning the last public release, or at least a warning about the possible issues with hardware older than 2/3 years...

[selden]

It seems to me that descriptions of the graphic card and MacOS restrictions would be an appropriate chapter in the Celestia WikiBook. There are many details that should be included which probably are not appropriate for Celestia's main site. The site does include a link to the FAQ, which says that Celestia works best on modern graphic cards.

[ElChristou]

It seems to me that descriptions of the graphic card and MacOS restrictions would be an appropriate chapter in the Celestia WikiBook. There are many details that should be included which probably are not appropriate for Celestia's main site. The site does include a link to the FAQ, which says that Celestia works best on modern graphic cards.

Could be of course, but don't you think we could centralize a bit some important points on the main site (the critical info, question of a few lines no more...)? perso I find it quite pointless, I mean there is the essential but nothing more (could be better, as this is the first place one is supposed to visit...)...

Concerning the Wiki I won't do any editing because of my English, but yes it's also a good place for this kind of stuff...

[selden]

Only Chris Laurel can modify the main site on Shatters.net. I doubt very much that he would be willing to turn over control to anyone else, and he certainly doesn't have much time to work on it.

That's one reason why the Documentation page exists on the site. That page includes links to documentation on the Motherlode, but strangely does not mention the WikiBook. Chris has contributed several sections to the WikiBook in the past year. Most of them are sections describing the new features available in V1.5 -- describing Frames and ScriptedOrbit functions. for example.

[selden]

Just because you think your English isn't good enough does not mean you shouldn't contribute to the documentation. You can write the rough draft and someone else can correct the English for you.

Also, you could write sections for the French language version of the Wikibook and get someone to translate them for you. The French version of the WikiBook is at
http://fr.wikibooks.org/wiki/Celestia

[dirkpitt]

It seems to me that descriptions of the graphic card and MacOS restrictions would be an appropriate chapter in the Celestia WikiBook.

Thanks for the reminder Selden. I've updated the Graphics Hardware chapter in the WikiBook to reflect known Mac OS X graphics driver issues.

[selden]

Thanks!

[dirkpitt]

For example,Open GL 2.0 is exclusive for Geforces 6,7,8 and Radeon X and X1XX.Why can??t HDR be the same?

Actually OGL2 ought to be available for GeForce 5 series and Radeon 96xx/97xx too.. but nitpicking aside, this is not what I meant when I said "backward compatibility".

HDR can be implemented in many ways, such as:
1) Hacked (lots of workarounds for lack of hardware blending etc)
2) Partially faked (16-bit floating point buffers with blending)
3) Completely "native".
These roughly correspond to 1->GF5, 2->GF6,7, and 3->GF8. So even among OGL2 cards there are many differences and compromises that must be made.

[ElChristou]

Just because you think your English isn't good enough does not mean you shouldn't contribute to the documentation. You can write the rough draft and someone else can correct the English for you.

In fact, despite the language, one must also know perfectly the topic to edit a document, so in the case of those rendering stuff, besides knowing the global situation, I think I'm not enough skilled to write down the issues in details...

Now, I'll edit with pleasure the French page as soon as possible with DW comments!

[ElChristou]

Done!

But at least a link on the main site would be welcome... Chris?