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[angrypig]

It's been a while since we published some screenshots with evening sun. So here are some new also with fixed shadowmap filtering but without final post process.

[RaikoRaufoss]

Looks very realistic!  Can't wait to see what they look like with post processing!

[angrypig]

Looks very realistic!  Can't wait to see what they look like with post processing!

Postprocess will only suppres the noise.

[RaikoRaufoss]

Postprocess will only suppres the noise.

Silly me. Will we see a video with the evening sun in it soon?

[angrypig]

And a few with Cessna...

[angrypig]

Postprocess will only suppres the noise.

Silly me. Will we see a video with the evening sun in it soon?

Definitely.

[Abc94]

Is the sun going to be an actual light source that moves around the world, or does the amount of light and shadows generated depend on what "time" it is in a certain area?


Either way it looks AMAZING!!  Beautiful!!  


I can't wait to see games made on this engine!  

[cameni]

Is the sun going to be an actual light source that moves around the world, or does the amount of light and shadows generated depend on what "time" it is in a certain area?

Well, seems to me like the same thing.

But the answer on the first part of the question is yes, there will be day/night cycle, and of course the Sun is in different position when viewed around the world.
If the second part of the question asked if the engine is being run with the light frozen as in certain time of day, then the answer is yes too
But that's only temporary because the Sun direction is currently at a fixed position, as specified in the configuration file.

[Abc94]

Is the sun going to be an actual light source that does not move, or does the amount of light and shadows generated depend on what "time" it is in a certain area?

(Fixed)

Yeah, I didn't phrase that question very well at all!  

What I meant was if you are in one area during the afternoon when the sun is in the middle of the sky, then go to another area where the sun is setting, are you actually looking at the same sun?  Is the sun a fixed light source?  Is the time of day determined by which position of rotation the Earth is at?  (Can planets in Outerra rotate?)

So I guess what I am asking is that if it is evening in one area, is it evening because of the area's angle to the light source, or is it because the engine determines what time it should be and shows the sun at the correct position?

[cameni]

So I guess what I am asking is that if it is evening in one area, is it evening because of the area's angle to the light source, or is it because the engine determines what time it should be and shows the sun at the correct position?

Somehow, this still means the same thing to me

Yes it's evening because the angle to sun from zenith is large, and thus atmospheric scattering computes evening colors. But of course, sun position can be set by what time it is, so .. .

Maybe the confusion stems from what a sun actually is. Was there no atmosphere, Sun would be just a bright star, a point light. Actually if you rise up in the engine, into the thinner atmosphere, apparent sun gradually shrinks until it's just a star. It's the atmospheric scattering that makes both the blue sky and the big circle of light. Sky is not a texture in Outerra, the colors are actually produced by computing the atmospheric scattering for given point on the sky or on the terrain. This also allows to change the parameters of atmosphere to simulate denser or thinner ones and varying aerosol density and such.

On the planet at various places you see the same sun vector, but the interpretation whether the sun is at fixed position and the planet rotates or if the sun vector is set to reflect current rotation angle of the planet is irrelevant - it looks the same, just different coordinate frames are used in our minds when we think of it
So in that sense, the planets in Outerra can rotate .. while not rotating at all

[RaikoRaufoss]

What I believe Abc94 is trying to say is: Is the sun the exact same sun in the sense that it is not just being projected to fit different types of day?  Anyway, will we see any videos of what the landscape in Outerra is like at night?

[cameni]

Sun is certainly not "projected", as I've said image of sun is created as an atmospheric effect, which it really is (the image). Also, sun is treated as a directional light because it greatly simplifies the formulas and the great distance allows the simplification.

Currently the landscape at night is dark, because there's no illumination from starlight and no moon. Additionally there has to be an adaptive HDR to compensate for vastly different levels of light during day & night, and for the fact that eye adapts to them.

[Abc94]

"Was there no atmosphere, Sun would be just a bright star, a point light. Actually if you rise up in the engine, into the thinner atmosphere, apparent sun gradually shrinks until it's just a star. It's the atmospheric scattering that makes both the blue sky and the big circle of light. ... the colors are actually produced by computing the atmospheric scattering for given point on the sky or on the terrain."

"Sun is certainly not "projected", as I've said image of sun is created as an atmospheric effect, which it really is (the image). Also, sun is treated as a directional light because it greatly simplifies the formulas and the great distance allows the simplification."

Wow...  Just wow...  I had no idea Outerra was capable of things like that, let alone any game.  That's pretty cool knowing that the sky and light you see is actually all being simulated!  I didn't know that anything like that was even possible!


And thanks RaikoRaufoss that was exavtly what I was asking!  


EDIT:  I just looked through the blog and found an article about "atmospheric scattering".  I guess I could have looked there first!  :p

[ZeosPantera]

I have a quick side question... How high?

Really, how far from the center of the earth can you go into outer space?

To the moon?       "384,403 km"
To the sun?    "149,597,892 km"

Depending on your answer the sun could actually exist and solve the riddle.

[cameni]

Actually there's no limit, just like we are changing reference frames on Earth to keep a good precision with floating point values, we can change the reference frames in space to have both good precision and covering a huge space.

But let's say that without changing the reference frame, and keeping 0.001m precision everywhere, we can get to ±2,251,799,814 kilometers from Earth. After that the precision will start getting worse, like 0.002m for another 2,251,799,814 kilometers and so on.