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Author Topic: Moon rendering  (Read 11062 times)

aWac9

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Moon rendering
« on: August 24, 2015, 10:04:20 am »

the introduction of the moon, rivers and wind has been a jump in the community knows outerra thank ..
with respect to the moon:
There are multiple effects that would add value to OT, for example the illusion effect moon or sun related optical illusion effect of size,,, or the moon on June 23 is huge and bright, etc .. but other effects less complex, having to do with the appearance to the human eye, it is to try to simulate the moon as we see,
for the day:

night (bright light with its own light (reflection):



Can we improve?

thanks
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Uriah

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Moon rendering
« Reply #1 on: August 24, 2015, 01:52:35 pm »

With regards to the Moon, the current one is simply a placeholder at the moment. If you open the objects menu, you'll actually find the model under outerra/test_moon, and I don't think there is a need to waste time improving it any more than necessary, as we're still waiting for the procedural moon, which once it arrives may make it necessary to re-evaluate the way it is rendered. However, OT has already done some things to make it look like the real thing looks to the human eye. For instance, the absolute angular distance of the Moon as seen from Earth is about 0.5 degrees. Now, if that were so in OT it would be exactly 12 pixels wide at an HFOV of 80 degrees on a screen of 1920x1080. Do the math: 0.5/80*1920. Now it sounds logical that would be true, but for a reason I don't completely understand that is actually not correct at all because of how it is rendered. For this reason the Moon is set to a scale of 4x, which scales it to the correct angular diameter as seen by the human eye, which is now 48 pixels wide at an FOV of 80 degrees on a screen of 1920x1080. This is defined in the file world.cfg by the following parameter:

Code: [Select]
moon-scale = 4.0,
Also, the Moon is in the correct orbit, using data from NASA, and therefore should have the correct Apogee and Perigee, making it bigger and small depending on the distance and time of year.  :D  You can verify the distance to the moon by opening the HUD and pointing it at the Moon, you'll see the distance which you can compare with its apogee/perigee. However, it won't be accurate according to the year, because there is no current definition of time since epoch in Outerra, that I know of, which would determine the Moon's exact position in its orbit.

Regards,
Uriah
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aWac9

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Re: Moon rendering
« Reply #2 on: August 24, 2015, 02:58:50 pm »

luckily I did not speak the lunar eclipse  ::)
thank you for your explanations  ;)

note: just a question.
my world.cfg have only 43 lines .. is that correct?
« Last Edit: August 24, 2015, 03:31:09 pm by aWac9 »
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Uriah

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Re: Moon rendering
« Reply #3 on: August 24, 2015, 03:51:55 pm »

Not sure exactly how many lines it should have. You can always save backup, then delete world.cfg and or eng.cfg and restart OT and those files will be freshly generated. This can help so solve many issues which are obvious.

Regards,
Uriah
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LeeP

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Re: Moon rendering
« Reply #4 on: August 27, 2015, 06:25:32 am »

I said it in the latest version section but I'm saying again here.

Man!! Partial lunar eclipse!! You guys are awesome!!!
The quality you guys are maintaining in this sim is just phenomenal !! 
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zzz

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Re: Moon rendering
« Reply #5 on: August 27, 2015, 06:53:57 am »

With my moon I had to put it at 3.8x10^7m up instead of 10^8 for it to "look right". In life the moon looks about the size of a 2 pence piece to me whilst at 10^8 it looked like a 5 pence piece.
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cameni

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Re: Moon rendering
« Reply #6 on: August 27, 2015, 10:48:20 am »

... the absolute angular distance of the Moon as seen from Earth is about 0.5 degrees. Now, if that were so in OT it would be exactly 12 pixels wide at an HFOV of 80 degrees on a screen of 1920x1080. Do the math: 0.5/80*1920. Now it sounds logical that would be true, but for a reason I don't completely understand that is actually not correct at all because of how it is rendered. For this reason the Moon is set to a scale of 4x, which scales it to the correct angular diameter as seen by the human eye, which is now 48 pixels wide at an FOV of 80 degrees on a screen of 1920x1080.

I would not say that 12px would be incorrect, quite opposite: for given FOV that you use in-game, it will be perfectly correct. Even though we all know the mismatch between our field of view of the display and the rendered FOV is causing all sorts of deformations, it's easier to adapt to it for objects that you can get close to. You get a deformed depth perception, but it doesn't feel entirely wrong.

However, it doesn't work for objects that are so distant that any normal distances on Earth do not change their perceived size for us. Here the real-sized Moon feels small, even though the same shrinking effect is present on all other objects - proportional to the ratio between the monitor and rendered FOV.

I'm still not entirely sure what to do about it. The same problem appears when you view Earth from Moon, but our brains did not learn what the size of Earth should be when viewed from there, so it feels less wrong even though Earth is not scaled (featureless Moon surface also adds to it).
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KW71

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Re: Moon rendering
« Reply #7 on: August 27, 2015, 01:56:31 pm »

Could the solution be a dynamic moon-scale? From 4 (or x) when you are in the earth surface to 1 when you are close to the moon? (Not sure if with a linear decay)
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josem75

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Re: Moon rendering
« Reply #8 on: August 27, 2015, 03:29:39 pm »

Could the solution be a dynamic moon-scale? From 4 (or x) when you are in the earth surface to 1 when you are close to the moon? (Not sure if with a linear decay)

This is what i was thinking too. Wondering if it was posible to do. I guess for the moon alone yes. Maybe the problem is when you build the moon with other objects, dont know if can scale all the objects too.
But well.. anyway the big scale x4 would be from a distance you will not see any object.. They can be the same.. When you are near and the scale is smaller the objects can then fit.
It would be a elegant good if posible
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HiFlyer

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Re: Moon rendering
« Reply #9 on: August 27, 2015, 08:19:02 pm »

And right on the heels of all of this Moon-Stuff for Outerra comes Unigine: Space

Just noticing how these products; Outerra and Unigine seem to be overlapping a bit in the race for a completely open world sandbox.



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LeeP

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Re: Moon rendering
« Reply #10 on: September 14, 2015, 02:44:12 am »

For me it seems that the moon always fallows the sun around. Is it supposed to have its own orbit?
Its just a see thru sphere it doesn't have a texture to it.
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bomber

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Re: Moon rendering
« Reply #11 on: September 14, 2015, 11:27:48 am »

And right on the heels of all of this Moon-Stuff for Outerra comes Unigine: Space

Just noticing how these products; Outerra and Unigine seem to be overlapping a bit in the race for a completely open world sandbox.


Yes,  there's a very strong ungine presence at the moment.....

A product to be taken seriously
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