Planetary illumination

[Commander William Diffin]

I have ticketed this several times this year with no response. The engine for planetary illumination is all wrong. Look—


A planet partly in shadow is represented in 2D by a semicircle on the lit side joined to a semiellipse on the shadow side. That shouldn't be a problem for computer programmers. It's basic stuff. Atmospheres do not diffuse light to cause it to wrap around the night side of a planet as in these wretched in-game depictions:


In this one the shadow is actually behaving like the illuminated part of the planet with the terminator curving the wrong way altogether:


Now see how it works in real life, first with the Earth:


And now even with planets that are practically all atmosphere like Jupiter and Saturn:


If FD still can't even work out where the terminator line should be between night and day on a planet from deep space, I fail to see how they're going to represent them accurately from the surface when planetary landings come out, and I foresee big problems in Horizons with it still being daylight on the surface with the sun way below the horizon. It's not like realistic illumination of a sphere is a complicated thing to achieve in computer programming. It's far more complicated to get it wrong as FD have done. Someone sort this out please.

 

[Iskariot]

Very interesting. You seem tho have a point.
I hope FD looks into this.

 

[Jon flint]

No disrespect intended but I wouldn't exactly call it game-breaking.

Relax, maybe drink a little less coffee and enjoy the game

 

[Spanksh]

Well, how it is in Elite actually is correct to a certain degree. Stars are not point light sources, but have quite a large size difference to the planets. Therefor planets are actually -always- (no matter the distance!) illuminated more than half the surface. Depending on the size difference and distance this effect can be quite severe.

For those who don't get what I mean, a simple sketch (remember, while the distances are usually way greater, so are the size differences!):



Also while taking your screenshots, you specifically forced the perspective to make the shadow line look straight. If you look at the picture of earth, you can actually notice that the lit side is slightly larger, since more than half of earth is exposed to sunlight, due to said size difference and atmospheric effects.
Here is an edited picture of earth, while the red line marks the widest distance, therefore the area where the light should stop, if the light source was as large as earth, or above if the light source was smaller. However it keeps going until the orange line, only then does the shadow start.


The shape of the shadow line on a sphere (straight/concave/convex) entirely depends on the perspective. It just requires stronger and stronger angles once the light covers more than half the surface (just look at moon phases, you get every single shape from strong concave to straight to strong convex, just from a change of perspective). To sum it up, the mistake doesn't (necessarily) lie in the lighting, but more likely in the observer.

 

[GraXXoR]

Those look like typical CG rendered lighting examples with a semi diffuse light source. Just looks strange because of the angle of the observer. They are not very flattering angles, however.

Far more relevant is that the problem is that the shadowy side of the planet is PITCH BLACK, but the sky isn't. That is unrealistic...
I am on the way back from the Core right now and some of the lighting was ridiculous. PITCH BLACK shadows on an Earthlike when the entire sky was chock-bang Full Of Stars.

 

[Jon flint]

Don't get me wrong, I may have teased a little but the OP does have a point depending on how far those planets were from their star, below are a couple of examples I've just knocked up in maya...





In my examples, the terminator doesn't go very far beyond the centre line of the planet but it's directly related to the size of the light source. If the ingame planets are close to a large star then their lighting is pretty correct,

Honestly this has never bothered me that much , im far more concerned that the terrain doesn't cast shadows in any of the revealed Horizons pics or videos!

 

[Mr_Blastman]

It is all a matter of perspective, OP. Each of these screenshots were taken from the same timeframe. But each one was taken from a different perspective. And as you can see... There's a variety of ways to render the terminator depending on the angle you are observing the world from. This was done in Space Engine, by the way.

I don't think Elite is doing a bad job.

 

[Mr_Blastman]

I don't mean to rub it in further but... we don't really need computer simulations to illustrate my point. All you have to do is go outside at night and look up at the sky, every night, for twenty eight days. You'll see the moon provide a wonderful example of perspective.

 

[Jon flint]

I don't mean to rub it in further but... we don't really need computer simulations to illustrate my point. All you have to do is go outside at night and look up at the sky, every night, for twenty eight days. You'll see the moon provide a wonderful example of perspective.

http://astropixels.com/moon/phases2/images/Phases10-5x3w.jpg

Okay you win, moon beats CG

 

[AndreyATGB]

Cannot unsee, thanks for that.

 

[govny]

there is definetly something wrong in the planetary lightning.
The shadow is far too small even for planets far away from the star.

 

[Kristov]

As pointed out, it's not the shadow that is wrong, it's your perspective that makes it appear so, simple as that. Fly around a planet and you'll see the terminator as a straight line, convex and concave, with less than half, exactly half and more than half of the planet lit up or in shadow, all in a single orbit, and that's going straight around the equator, get some angles going on and you can really have some fun with perspectives and how much is lit up or in shadow, shape of the terminator...yeah, that's not a bug, that's how lighting actually works.

NOW, if you'd instead been complaining about the fact that ONLY a single light source is used and it's usually a visible white light source at that, THAT would be something to put in a ticket about. Known issue, David said they are working on that, it's just a very resource intensive thing to do. I know this from my own 3d work, multiple light sources eat your overhead alive, and doing 3d artwork, not a big deal, just means my render takes longer. Real time gaming, THAT is a huge issue, you can't let it take longer to render the scene, it needs to be done real time, which means you have to use a lot more resources to do it, which means you need a better rig to make it run smoothly and not drop the frames to the single digits or worse.

 

[majogl]

The lighting seems to be the cause of major tech problems in this game... Even when it comes to a body accepting light from 2 different sources (multiple shadows), the issue has been with us since the release and still no fix. Even when asked about planet rings casting shadows, DB was very evasive, like they do not yet know if they will be able to fix this within acceptable performance fluctuation...

 

[torc]

i've always loved discussions about this features, because i really feel the need to see a ''correct as possible'' galaxy...this is because i'm waiting for a good exploration trip, just because i'd like to enjoy a truly space experience.

i think there are also problems with HDR, and planets albedo isn't implemented correctly yet.
As you may notice, you have a bright galaxy and space even very close to planets and atmospheres, and this shouldn't happen in real life...as istance i'd like to have a fully visible and bright milky way only in deep space, and near planets (like our earth) you should see a very faint and almost monochromatic milky way...that's why i think a good High dynamic range management related to planets albedo would solve a lot of graphic issues (OP mentioned the Pitch black dark side of the planet and the background too bright).

If you google planets albedo you may see the amount of light each planet reflects based on his compositions and atmosphere. and you can understand wht gas giants are so bright even if them are so far away from suns, and why mercury doesn't reflect almost any light because it's basically a burned rock

This would be the first step with the fixed terminator line...multiple light sources and shadows could wait until they optimize the game for them since it's very recource expensive IMO.

My 2 cents

 

[Spanksh]

The lighting seems to be the cause of major tech problems in this game... Even when it comes to a body accepting light from 2 different sources (multiple shadows), the issue has been with us since the release and still no fix. Even when asked about planet rings casting shadows, DB was very evasive, like they do not yet know if they will be able to fix this within acceptable performance fluctuation...

Well it's not something that needs fixing, since it's not broken. Multiple light sources and ring shadows are ACTIVELY disabled (as officially stated repeatedly - last time by David Braben in the Horizons stream). Frontier is seriously afraid of lowering performance even in the highest settings, which is kinda laughable considering the computer setups many people have here. But then again I don't know any details about the engine and how well it could even handle such a thing (if at all). Anyways these things won't be in the game until Frontier finds a performance friendly way to enable it.

 

[Kristov]

The lighting seems to be the cause of major tech problems in this game... Even when it comes to a body accepting light from 2 different sources (multiple shadows), the issue has been with us since the release and still no fix. Even when asked about planet rings casting shadows, DB was very evasive, like they do not yet know if they will be able to fix this within acceptable performance fluctuation...

Because it's very expensive to do halfassed, even more expensive to do properly, and that's simply how it works. Real time lighting and shadowing is extremely resource intensive with a single light source, add just 1 more light source and the resource usage goes up exponentially, so it gets really hard on hardware really quick. I've been in systems with 5 suns all within 1000 LS of the central star, that kind of lighting and shadow creation...OUCH!

Rings casting shadows on planets seems pretty easy right? Just some half circle lines on the ground, right? Only, Horizons is changing all the planets to be actual 3d bodies, not spheres with some topo on them. So now we're trying to create shadows from objects thousands of kilometers away, possibly through an atmosphere(which creates a whole NEW set of issues), on a rotating 3d spherical body. Oh, and that ring, it's not actually a SOLID object, so it's shadow will need to take that into account, which makes things even more complicated.

It ain't easy, despite what people who have absolutely NO experience in this stuff think.

 

[torc]

Because it's very expensive to do halfassed, even more expensive to do properly, and that's simply how it works. Real time lighting and shadowing is extremely resource intensive with a single light source, add just 1 more light source and the resource usage goes up exponentially, so it gets really hard on hardware really quick. I've been in systems with 5 suns all within 1000 LS of the central star, that kind of lighting and shadow creation...OUCH!

Rings casting shadows on planets seems pretty easy right? Just some half circle lines on the ground, right? Only, Horizons is changing all the planets to be actual 3d bodies, not spheres with some topo on them. So now we're trying to create shadows from objects thousands of kilometers away, possibly through an atmosphere(which creates a whole NEW set of issues), on a rotating 3d spherical body. Oh, and that ring, it's not actually a SOLID object, so it's shadow will need to take that into account, which makes things even more complicated.

It ain't easy, despite what people who have absolutely NO experience in this stuff think.

I agree with you, but i think there would be some kind of ''turnaround'' regarding this issue that FDevs can achieve if them wanna try to give a better look.
I'd start to thin that if you are in the middle of multiple light sources, would be enough ''fade out'' the first light shadow and ''fade in'' the upcoming light source, instead having an immediate change as it happens now when you travel from a star to another.

 

[Jon flint]

It ain't easy, despite what people who have absolutely NO experience in this stuff think.

More than a little presumptuous to assume that nobody on these forums has any development experience.

That being said I do completley agree with the rest of your post.

The game does already support multiple shadow casting light sources (see ship headlights), just not ones stretching over an entire system.

 

[Privata]

I love the game (best spacesim ever) but I have given up on them fixing the graphics this season
The draw distance tiny , 90% of dynamic showdows gone , number of stars in the sky gone down , textures reduced , lods the wrong colour in roid fields , no more fog with volume...
its a shame , they will fix it in the future but I dont know when and I am scared that there will be another downgrade in terms of graphics in 1.5 because so far there been one with every update (this one was station lods are less good)

Again I LOVE elite and think its the best game ever , but its a damn shame that they ignore the high end user base 100% and inject all the nerfs into the ''ultra'' settings instead of keeping them in low or adding extra-low.

 

[Kicks]

I agree with you, but i think there would be some kind of ''turnaround'' regarding this issue that FDevs can achieve if them wanna try to give a better look.
I'd start to thin that if you are in the middle of multiple light sources, would be enough ''fade out'' the first light shadow and ''fade in'' the upcoming light source, instead having an immediate change as it happens now when you travel from a star to another.

Kristov is quite right... it's not so much "experience" (and I believe the OP has been more than "nasty" in his presentation), but the more lights you add to a scene, the more computationally expensive it is. FD could probably easily do it 100% realistically. But if they did, they have to justify the extra work that will be available to a probably small % of people with the hardware that will run the game at a decent speed. You can fake *some* things, but FD (rightly in my opinion) try and get things as realistic as they can.

Add in some binary/trinary star systems and things get interesting really fast.