Atmospheric dawn-shines, fog, and lens flares

[IlyaG]

http://www.fpsoftlab.com/earth3d.htm

Go to that site and download a shareware 3D screen saver of Earth (also available are Mars and the Moon). What this program does is what Celestia SHOULD be able to do, and someone needs to get on it right away

Specifically, I'd like to point out the less bland, more realistic rendering of Earth, thanks mostly to atmospheric fog. It lightly blurs the edges of the planet, making it highly more photo-real than atmosphere planets in Celestia. (Also, I believe the texture itself is more photo-realistic than the default one in Celestia)

Also, note the animation when the sun approaches and then goes behind the planet's surface. It is brightly and photo-realistically reflected by the atmosphere, giving off a bright orange light (the Moon version of this program realistically does not have this effect, because the Moon has no atmosphere). This effect must be reproduced with Celestia. It is absolutely phenominal here!

And finally, the lens flare. Isn't it about time we got one for Celestia?

Someone needs to study this screensaver and try to reproduce the amazing effects in it. This is a great example of what Celestia should look like in the future, or at least what Celestia's developers should strive for.

[Stargazer_2098]

There is only one thing I didn't like about those screen-savers; the price tag. I mean , I would rather pay for something like Celestia, then having to pay many $ for some screen savers.
As for importing this to Celestia... Yes I belive it should be possible to use the textures of the screen-saver on the planets in Celestia, but I am not a developer, so I can't be sure.
I did like the graphics tough, so I hope it is possible to do so.
Anyone?

Stargazer.

[Pixel]

Spectacular!!!

They don't use powerfull 3d-accelarators nor big textures, and still you have nice effects in hand!

I have just fectched the textures from the screen saver. They are noway hi-res. They are just 2048x1024 ...and... he-he-he - they used bathymetry map (ocean floor relief) for oceans, instead of ocean surface. Strange idea indeed - one can clearly see the Atlantic Ridge .
Except for oceans, no shadow-relief to land is present in the texture itself. They have no bump map either - so you should not see any bump-map effects. They have specular map, clouds map, night-lights map and a bunch of flare images (images of circles). Amazing space sunsets and sunrises are achieved not by complex simulation of iteraction of light and athmosphere but by simple flare effects - i see the fixed images of sunset flares. So i think it is not possible to zoom in/out without artifacts when you watch sunsets - so it is not true iteractive 3D. However there are good ideas that can be adopted in Celestia:

1) Although texture is low-res (2048x1024), i think the colors are really nice and adjusted "naturally". BlueMarble images are far from that.

2) specular map, clouds map and night-lights maps are all in different files and are all in resolution 1024x1024. This allow to reduce memory requirements.

3) nice trick for Moon. They used there moonBump map that has higher resolution than base moon texture. 2048x1024 vs 1024x512. base moon texture again has better collors than celestia's ones.

[marc]

[
And finally, the lens flare. Isn't it about time we got one for Celestia?

The lens flare issue has been bought up before.
Who here has actually seen a real lensflare with a mk1 eyeball?
Is it not an unwanted effect which is produced by poor quality optics?
Lensflare, no thanks too cheesy.
I also have some doubts on the dawn shine effects. They aren't exaggerated are they?

We really need to model celestia on real photographs and not on other programs which look cool.
Anyone got any good links to real earth photographs? it would be nice to do the comparison

[Rassilon]

Sunsets I heard [The swelling red sun] is caused by the copper in the atmosphere...Is this correct? Something my roommate told me at one point...This I would like to see on earth atleast...

[IlyaG]

Who here has actually seen a real lensflare with a mk1 eyeball?

I don't agree with your opinion that the Celestia program is supposed to reproduce eye-quality visuals. Is it not animation? Is it not displayed on a computer monitor? The visibility (or lack thereof) of lens flares by the naked eye is inconsequential. Besides, I wear glasses and therefore DO see lens flare with my own eyes. So how do you defend that? By saying I'm some sort of exception to the rule?

Celestia in my opinion does not represent naked eye-quality visual effects, otherwise there'd be a lot more things we'd need to change with the visual presentation of the program (labels, orbits, constellations being just a few examples)

There's nothing wrong with improving the visual presentation of Celestia. It doesn't have to be just about scientific realism (and I'm still not backing down from my opinion that lens flare is realistic)

[abiogenesis]

Rassilon wrote:

Sunsets I heard [The swelling red sun] is caused by the copper in the atmosphere...Is this correct? Something my roommate told me at one point...This I would like to see on earth atleast...

Actually, I believe the reason for the red-shift of the sun during sunrise and sunset is due to the greater distance the light has to travel through the atmosphere. During sunrise and sunset, when the sun is near the horizon, there is a much greater volume of Earth's atmosphere through which the light must travel to reach your eye. This slows the light down, causing a spectral shift toward red.

I'm not sure exactly what the effect would look like from space. Earth's atmosphere is quite thin, relatively speaking. It takes a severe angle to notice refraction when standing on the surface. This is already modeled in Celestia by the change in color in the atmosphere's around Earth and Mars. I think the current model is quite nice, but if it can be improved, either through realism or aesthetics, I'm all for it.

-abiogenesis-

[Sum0]

While this discussion just seems to be a long excuse to be nasty to Celestia , I was impressed by the screensaver, especially by its speed. The problem is, Celestia needs a decent graphics card to get cool effects and a high frame rate. However, programs like this screensaver show that even a terrible Rage 128 can look good next to a Geforce.
I hate to sound like i'm looking a gift horse in the mouth, but it would be nice if Celestia was more compatible (i'm not sure that's the right word) with more setups, not just high-end PCs.

Of course, if I get a Geforce or something, I'll probably say something like "Well, if you're not prepared to shell out the cash, then you can't really expect much..."

[Pixel]

While this discussion just seems to be a long excuse to be nasty to Celestia , I was impressed by the screensaver, especially by its speed.

How can you compare the speed? The screensaver is not even proven to be realtime 3D application. Nor does the nice looking StarryNight planetarium.

[Guest]

Rassilon wrote:

Sunsets I heard [The swelling red sun] is caused by the copper in the atmosphere...Is this correct? Something my roommate told me at one point...This I would like to see on earth atleast...

Actually, I believe the reason for the red-shift of the sun during sunrise and sunset is due to the greater distance the light has to travel through the atmosphere. During sunrise and sunset, when the sun is near the horizon, there is a much greater volume of Earth's atmosphere through which the light must travel to reach your eye. This slows the light down, causing a spectral shift toward red.

Well, although the red color of sunset is indeed linked to the fact that light has to travel a longer distance through the atmosphere this red shift is not due to light slowing down.

The blue color of the sky as well as the red color of sunrise and sunset can be explained by the Rayleigh scattering. O2 and N2 air molecules scatter the sunlight. The amplitude of the phenomenon is a function of the wave length, it is more effective for short wave length which explains why blue is diffused while red is not.

CT

[Rassilon]

Which could also explain how vision gets distorted in high tempratures causing a mirage effect in some cases...Isn't this almost a reflection of the sky...the light rays bouncing off the ground? That would be cool to see...

Noctis IV I notice does a bit of this...

[IlyaG]

Can someone extract or simulate the texture of Earth (and the clouds) in this screensaver and stick it into Celestia? This Earth texture makes Celestia's look incredibly cartoonish.

Also, the atmospheric fog/fuzziness around the planet... it produces a very photo-realistic effect. Any way to do this in Celestia?

[bork]

I cant resist the chance to stir

Besides, I wear glasses and therefore DO see lens flare with my own eyes.

Must be pretty fancy glasses.

P

[booger]

Can someone extract or simulate the texture of Earth (and the clouds) in this screensaver and stick it into Celestia? This Earth texture makes Celestia's look incredibly cartoonish.

I would think that that would be rather immoral and illegal without the authors permission.

[Pixel]

Can someone extract or simulate the texture of Earth (and the clouds) in this screensaver and stick it into Celestia? This Earth texture makes Celestia's look incredibly cartoonish.

Also, the atmospheric fog/fuzziness around the planet... it produces a very photo-realistic effect. Any way to do this in Celestia?

Being amoral, i already have them, but i am not impressed at all. Specular map was fake and i use my own. Collors are good, but resolution is rather low. They look good only at the same distance as viewed in the screen saver.

[Guest]

Can someone extract or simulate the texture of Earth (and the clouds) in this screensaver and stick it into Celestia? This Earth texture makes Celestia's look incredibly cartoonish.

Also, the atmospheric fog/fuzziness around the planet... it produces a very photo-realistic effect. Any way to do this in Celestia?

Being amoral, i already have them, but i am not impressed at all. Specular map was fake and i use my own. Collors are good, but resolution is rather low. They look good only at the same distance as viewed in the screen saver.

That was exactly my impression, too. I am not sure why people seem to be so excited about this. I can also easily increase the fog level in my clouds, but I am not sure whether this is what /I/ really want.

Bye Fridger

[Pixel]

That was exactly my impression, too. I am not sure why people seem to be so excited about this. I can also easily increase the fog level in my clouds, but I am not sure whether this is what /I/ really want.

Bye Fridger

However i wouldn't miss the illumination effects - that is where earth colors tends to bright blue
near corona.

[Rassilon]

Theres also the fact with right lighting and texture effects....any one of us photoshop or gimp users can reproduce...as fridger mentioned the cloud fog...any of the effects with a little texture f/x...

spectural and haze at the correct amounts could easily blow away that screensaver...atleast from space...the surface chris might have to add a few more things...

[Pixel]

spectural and haze at the correct amounts could easily blow away that screensaver...atleast from space...the surface chris might have to add a few more things...

The effects you see in the saver are pure 2D. You can't do this simple by adding haze fog , wich fog any way i do not see with my Gf2. Btw the screen saver can really pretend for photorealism, whatever it means. I have seen many photos of the Earth from space and must admit that BlueMarble images are really cartoon-like.

[Rassilon]

Thats why currently I'm working on a better layout of the earth...I am currently looking for a good map of the ocean floor...

And I agree they are a bit cartoonish...but with a bit of green haze over the ocean and a nice ocean bumpmap...might make a better view...

Also chris mentioned maybe adding specular and bumpmap effects in the upcoming version...all is needed then is cloud shadows