View Full Version : [TEC] Guys I am having a brain fart need help with sun
leovampire
08-25-07, 07:21 PM
Okay would 90 and -90 be when the sun is at it's highest point in the sky?
what I want to do is make it so the sun slowlystarts to look smaller as it rises in the sky seeing the point of size refference fades as it rises. And then have it go back to original size as it is setting.
I also want to do this with the moon.
Rather than resize them and still not have the proper effect.
Once I get this done I will be able to get the proper reflection effect's for the ocean and what not so help is apreciated.
sneekyzeke
08-25-07, 07:32 PM
...so i don't know about the minus sign, but from horizon to horizon would be 180 degrees, so 90 would be half or "noon".
leovampire
08-25-07, 07:36 PM
#1 is set at 90 and #13 is set at -90
So I guess I need to do it on 15 deg incrments and seeing 1 is full size I will have to do 1 for size on #6 #7 and #8 then reduce the size by 0.1 for each other state so that it is at it's smallest size at 90 deg.
Does that sound right?
The only thing that sucks is the moon's size dosn't seem to be adjustable so you can do the same thing with that.
The sun only looks bigger on the horizon because you have a reference to compare it to. It should be about 30 minutes of arc no matter where it is.
The moon should be about the same (which is why eclipses happen the way they do).
tater
leovampire
08-25-07, 08:27 PM
relitive size as the sun tater?
Both are about 30 degrees of arc (~32 for the sun) (my astrophysics background has to be useful sometimes ;) )
Degrees are degrees are degrees. Their size doesn't change due to sky position.
tater
leovampire
08-25-07, 09:12 PM
the game dosn't know how to render the effect we have in real life. We know the sun and moon look bigger when it is close to horizontal because there is a reference point to campair. And when it gets higher in altitude or angle if you want it seems to be smaller because that reference is now gone.
But the game dosn't know how to create that effect unless you teach it and so far the only way seems to be making it smaller as the sun changes angle in the sky. And then slowly resize it as it comes back down near the horizon again.
But they didn't make the same effect available for the moon it stays a constant which is a problem.
It will have some reference if you see it rise/set next to a reference---like a mountain, or a ship.
<shrug>
tater
leovampire
08-25-07, 09:39 PM
If that were the case the game wouldn't have a set up for adjusting the size of the sun for each degree of altitude.
DirtyHarry3033
08-25-07, 09:45 PM
Well, just my opinion, it seems to me it's all an optical illusion as far as "apparent" size goes. True size of sun or moon of course don't change, and despite what people may think the atmosphere does not "magnify" either sun or moon when it's close to horizon.
What does happen with respect to the sun at sunset or sunrise, is all that intense light is being scattered thru a much thicker layer of atmosphere than when it's right overhead. And the light is more diffused. So the light "spreads out" more, if that makes sense, and it is possible to actually observe the sun's disc for a second or 2. Try looking directly at the sun at noon on a clear day, well you can't do it so you have no point for comparison!
The moon otoh, is like a candle in comparison to the sun's searchlight. You can look straight at it, as long as you like, no matter where it is. And there is very little light to get wildly scattered by that thicker layer of atmosphere when it rises or sets.
So anyway, the moon's size is more familiar. On land, when it rises or sets you have all kinds of familiar references to compare it to - buildings, trees, hills and so on. When it gets overhead your reference points are taken away and as a result it appears smaller.
But at sea, you don't have any of those reference points. Nothing but a flat, featureless horizon which is little better than the zenith of the sky. I've never been at sea on a clear night with a full moon rising, but I'd bet it wouldn't look much (if any) larger when rising than when it was right overhead...
DH
leovampire
08-25-07, 09:55 PM
which has helped a bit I have been working with the size vs altitude and adjusting the halo effect's and angle of reflections vs the sun's relative angle in the sky and starting to come up with some nice effect's on the water and sub and ships.
So I guess the discussion helped a bit to get me thinking more and picture it in my mind enough to get it working better in the game.
Just slow going as I have to learn more about how the effect's work vs settings for the game. Gets a bit confusing when the game switch's to negative numbers as the sun goes over the absolute highest point so have to reverse thinking to negative numbers.
DirtyHarry3033
08-25-07, 10:12 PM
Leo you work too hard! You should just take a break and play the game for a while ;)
Your work is appreciated though, I'm loving LBO 2.0 and begging for a storm so I can fully appreciate it. However virtual weather seems as un-cooperative as the real thing and I've been sailing for several days in a dead calm :damn::damn::damn:
Before I installed LBO 1.0, I had a patrol where I had nothing but 15 m/s winds and thunderstorms from the time I left port until I docked. Now I can't get a storm if I get down on my knees and beg for it!
Shouldn't be hard to get accustomed to the +90 -90 stuff, just think of the zenith as 0 degrees and it should all fall into place...
DH
leovampire
08-25-07, 10:22 PM
Here is an example picture. I have been adjusting relative size vs angle hight and angle's of reflections and the halo fade effect's and more and this is what I have already come up with. Not perfect but will be soon enough! Also working with the reflections in the water vs the suns angles to get more realistic effects.
http://static.filefront.com/images/personal/l/leovampire/93141/carribsuys.thumb250.jpg (http://gallery.filefront.com/leovampire//739543/)
I may not know how to make dds files and images but I know how to work the environment
effects enough to make it is real as possable for everyone to enjoy DirtyHarry3033. Just need
to learn the in's and out's of the rest of the Scene file and I am getting there.
sneekyzeke
08-25-07, 10:56 PM
http://www.skyandtelescope.com/observing/objects/javascript/3305541.html#
scroll to bottom of page to use it.
leovampire
08-25-07, 11:06 PM
but unfortunatly I havn't found any ajustments in the game that control date's vs angular possition and that is getting into the longitude and latitude views and that dosn't come into play in the game at all. You could be anywhere in the ocean and see the same effects where as in real life you possition make's a difference vs what you see.
Like for example in real life doing a patrol in the upper part of the Bering Sea there wouldn't be as much day light time as there is every where else we normaly patrol but the game isn't set up to simulate that.
Maybe some time in the future the games will be that accurate.
Thanks for the info anyways. :up:
If that were the case the game wouldn't have a set up for adjusting the size of the sun for each degree of altitude.
They have it there, doesn't mean they are right. The only realistic reason to use that capability would be if the game rendered the sun and moon different sizes due to the geometry of the game, and the adjustment was needed to make them constant.
You can easily measure the moon at moon rise or set, and again at zenith, and there is no difference. It's an illusion. With the sun it's exaggerated due to the fact that at sunset you can actually look at it long enough to dwell on details.
The sun/moon should be constant in angular size. They vary a little based on date (earth-sun distance, and earth-moon distance), but the difference caused by an earth radius is too tiny to matter.
tater
Bill Nichols
08-26-07, 08:21 AM
Here is an example picture. I have been adjusting relative size vs angle hight and angle's of reflections and the halo fade effect's and more and this is what I have already come up with. Not perfect but will be soon enough! Also working with the reflections in the water vs the suns angles to get more realistic effects.
http://static.filefront.com/images/personal/l/leovampire/93141/carribsuys.thumb250.jpg (http://gallery.filefront.com/leovampire//739543/)
I may not know how to make dds files and images but I know how to work the environment
effects enough to make it is real as possable for everyone to enjoy DirtyHarry3033. Just need
to learn the in's and out's of the rest of the Scene file and I am getting there.
Dirtyharry is absolutely correct, the sun's size does not change with altitude. It's simply an illusion due to reference points. (I, too, have an astrophysics background and have also done celestial navigation at sea :know: ).
Here's a pic I took last year while cruising the Caribbean:
http://i231.photobucket.com/albums/ee4/billn53/Sunrise_at_Sea.jpg
:ahoy:
I think the developers were trying to show the lens effect of the atmosphere at very low elevations but exaggerated it too much.
Except the "lens effect" is virtually nonexistant in RL, so they'd me modeling fantasy ;)
The most you will get is distortion, but no appreciable size change. Scattering will obviously redden the image as the blue is selectively scattered in an isotropic way (leaving more red light along the path length to the detector (your eye)).
tater,
You are probably correct scientifically but go outside at sunset, moonset, etc. and use the MK 1 eyeballs and you will see it "appears" to be a larger diameter at very low elevations but nowhere near the size modeled in SH 4.
Let's just say at the horizon it gets "distorted" and appears larger but if it's rising it quickly gets to it's correct apparent size in the sky.
Like you I live someplace where I get lots of pretty sunsets, almost every day (I can see 85 miles away out my west windows).
The larger appearance is entirely illusion. Such an illusion can be replicated in SH4 (with a correct sun size) by watching the sun set over some land, or behind some targets :D
tater
That's what I've been saying.... it is an illusion but it is present in RL.
I also said it is a highly exaggerated "illusion" in vanilla SH4.
You and I live in the desert where we can see this illusion. I know I've seen 60 miles away but even here there is more and more pollution showing up in the atmoshere.... mainly emissions from automobiles as the population increases. I can see a yellowish, brownish smog cloud just above the horizon in the direction of Las Vegas, NV. on clearer days. That is about 85-90 miles as the crow flies.
Rockin Robbins
08-26-07, 01:03 PM
Okay would 90 and -90 be when the sun is at it's highest point in the sky?
what I want to do is make it so the sun slowlystarts to look smaller as it rises in the sky seeing the point of size refference fades as it rises. And then have it go back to original size as it is setting.
I also want to do this with the moon.
Rather than resize them and still not have the proper effect.
Once I get this done I will be able to get the proper reflection effect's for the ocean and what not so help is apreciated.
Leo, the sun's apparent size does not change as it transits. Anything you think you see is an optical illusion, but it's size is always within a couple hundredths of a degree of ½º diameter. The same is true of the moon, which changes slightly (not enought to judge without measurement devices) due to it's apogee and perigee in its orbit around the Earth, but it also does not change in size with its relationship with the horizon. By the way, the moon also subtends ½º in the sky. Modeling something that doesn't exist seems to me to be a bad idea. That's the bad news. The good news is that since it is an optical illusion, it is already successfully modeled and you don't have to do a thing!
If you insist, +90 is straight up, -90 is on the other side of the earth, straight down.
Rockin Robbins
08-26-07, 01:13 PM
tater,
You are probably correct scientifically but go outside at sunset, moonset, etc. and use the MK 1 eyeballs and you will see it "appears" to be a larger diameter at very low elevations but nowhere near the size modeled in SH 4.
Let's just say at the horizon it gets "distorted" and appears larger but if it's rising it quickly gets to it's correct apparent size in the sky.
But tater is saying that happens between your ears and not in the sky. Similarly, with no modifications whatever it will happen between your ears in SH4 and so no mod is necessary for solar and lunar size.
tater,
You are probably correct scientifically but go outside at sunset, moonset, etc. and use the MK 1 eyeballs and you will see it "appears" to be a larger diameter at very low elevations but nowhere near the size modeled in SH 4.
Let's just say at the horizon it gets "distorted" and appears larger but if it's rising it quickly gets to it's correct apparent size in the sky.
But tater is saying that happens between your ears and not in the sky. Similarly, with no modifications whatever it will happen between your ears in SH4 and so no mod is necessary for solar and lunar size.
Maybe I'm misunderstanding. Yes If there was no atmoshere, If there was no knife-edge distraction, If there was no diffusion etc. etc. The "apparent" "diameter" of either the Moon or the Sun would always "appear" to be the same no matter what elevation above the horizon you observe it but these are scientific facts that even good astronomy programs have corrections you can apply as an option to correct for abberation, knife-edge distraction, diffusion etc. etc. The human eye DOES perceive a different diameter at VERY LOW elevations but the effect is higly exaggerated in SH 4.
So it is REAL in REAL LIFE. Scientifically the distance from the object determines it's "ACTUAL" angular size.
(not counting gravitational bending which can even obscure a scientific measurement!)
Perhaps in SH4 the lens effect of the atmosphere isn't programmed in so they opted to change the diameter of these objects to give the "ILLUSION".
Percieved as larger doesn't mean it is larger.
Measure the moon on the horizon. Measure the moon at zenith. No difference.
It's an illusion, it is not an actual change.
Distortion, mirage, etc are all possible visual effects that are demonstrable, but the diameter doesn't change to the extent you could see it with the naked eye. BTW, if anything they are actually (with very precise measuring gear, not the naked eye) SMALLER at the horizon since they are 1 earth radius farther away than zenith (there is also a squashing effect, actually, no size increase).
Percieved as larger doesn't mean it is larger.
Measure the moon on the horizon. Measure the moon at zenith. No difference.
It's an illusion, it is not an actual change.
Distortion, mirage, etc are all possible visual effects that are demonstrable, but the diameter doesn't change to the extent you could see it with the naked eye.
Maybe my eyes are different then because on moonrise it sure looks big! It quickly diminishes in appeared diameter as it rises fully above the horizon completely.
I used to take a visual sighting of the moon to aim my parabolic antenna to do "moon bounce". This is bouncing radio signals off the moon and back to earth. I didn't have a proper polar mount or connected to a computer program so I kept it aligned using my eyeball.
Your talking about laboratory instruments to measure it, I'm talking about how it appears to the HUMAN eyes and BRAIN.
Again, looking and measuring are different. Measure the moon and try it.
Anything that you think you see is, as RR put it so well, between the ears, that's why it's called an illusion :)
Again, looking and measuring are different. Measure the moon and try it.
Anything that you think you see is, as RR put it so well, between the ears, that's why it's called an illusion :)
We both have said this.... it is an illusion but an illusion that is present in RL.
Bill Nichols
08-26-07, 02:41 PM
Ah, but it's not an illusion when I'm looking at the moon or sun with my periscope. In both cases they should always extend the same number of hashes.
:|\\
Rockin Robbins
08-26-07, 09:03 PM
Ah, but it's not an illusion when I'm looking at the moon or sun with my periscope. In both cases they should always extend the same number of hashes.
:|\\
And that's why it's important for the moon to be its real 30' size in the sky. The periscope is a measuring device and is it too much to ask that it measure correctly?
Hey tater, how about a mod for extended objects in the night sky. The Milky Way and a few major nebulae would be really cool in the middle of the Pacific. M33, M32, NGC 253, the Orion Nebula, The Beehive Cluster (M44), the Coma Cluster (some obscure catalog number, lol) should all be easily visible to the naked eye at night on a submarine in the middle of nowhere. We could turn SH4 into a planetarium!:arrgh!:
leovampire
08-27-07, 02:58 PM
I will work on making the sun set's and reflections for it on the water more like that. I started getting the effect just not the coloring by adjusting sun reflection angles vs possition of the sun. It is comming together just needed a day off for an aniversarty party.
leovampire
08-28-07, 04:16 PM
that should make this project go smoother I havn't given up on it just working on other stuff inbetween this. So maybe the work will go a little smoother now and I can get the reflections correctly working faster. One of the new things that you will be seeing is cloud reflections on the smoother surfaces of the ocean when the winds are at 0 mps and now both sun and moon reflections can be adjusted not just the sun.
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