Universe Sandbox

Universe Sandbox => Universe Sandbox ² | Discussion => Topic started by: Cesrate on November 05, 2014, 09:10:04 AM

Title: G Type stars like Sun should have snowwhite color instead of yellow
Post by: Cesrate on November 05, 2014, 09:10:04 AM
As is shown in pic
(http://upload.wikimedia.org/wikipedia/commons/9/98/STS-129_Zvezda_sunrise.jpg)

Edit by Bla: Resized image
Title: Re: G Type stars like Sun should have snowwhite color instead of yellow
Post by: Gordon Freeman on November 05, 2014, 09:18:00 AM
But they are.

P.S. I'd recommend changing that to a link since the image is so huge
Title: Re: G Type stars like Sun should have snowwhite color instead of yellow
Post by: Cosmos on November 05, 2014, 09:19:06 AM
But they are.
What? Yellow?
Title: Re: G Type stars like Sun should have snowwhite color instead of yellow
Post by: Gordon Freeman on November 05, 2014, 09:20:19 AM
Well, in the image, the sun is kinda yellow. But, yeah in US2 they're the same color as the sun in the image.
Title: Re: G Type stars like Sun should have snowwhite color instead of yellow
Post by: gabriel.dac on November 05, 2014, 09:32:11 AM
The sun in the image is perfectly white. Are you high?

Anyway, that is an interesting detail I didn't notice. The Sun in US² is yellowish. In real life the Sun is white (even though it has slightly more green than other colors, proportionally speaking (that's why plants are green))
Title: Re: G Type stars like Sun should have snowwhite color instead of yellow
Post by: Gordon Freeman on November 05, 2014, 09:40:03 AM
that's why plants are green


Are you high?
Title: Re: G Type stars like Sun should have snowwhite color instead of yellow
Post by: Georg on November 05, 2014, 09:41:24 AM
Good point! Here's the explanation for why they don't look white in the Sandbox:

The brightness of an object in an image is determined by the amount of light it emits as well as the camera settings (aperture, exposure time, sensitivity of the medium etc). When you take the picture you're setting everything up to make the result fall into a useful range. In the image you posted, the goal was to pick out the details of the ISS and the glory of the sun's light at the same time.

Note the absence of other stars in the background of the image? They should be visible, there's no atmosphere to hide them... but at the exposure necessary to see the ISS they are invisible, as their comparatively low light emission doesn't get enough time to make it into the image. If you were to expose the image long enough to capture the background stars, the ISS and our sun would look like a featureless white blob of sheer inferno.

To be able to pick out the surface detail of the sun (and other bright objects) in Universe Sandbox² we deliberately set our "virtual exposure" to be quite low. In many cases, it's more important to us to show the nature of things in a detailed fashion than to depict them like you would see them with the naked eye. If we set it up to look like you would see it with your naked eye, we would

- need a monitor / display device that can be at least as bright as the sun
- be unable to show anything else on screen as the sun would just white-out everything
- have to start writing in a braille manual (you'd be blind pretty soon).

There are ways to handle exposure dynamically based on image content (HDR rendering with dynamic exposure). Those algorithms mimic the adaptation process of the human eye and also put all objects in the scene into a useful range by adjusting exposure like a photographer would. But even using those wouldn't help us much: the sun would still be featureless and white, and everything else in the scene would have to be rendered a lot darker.

Seems that our eyes just aren't the best tools for space exploration ;) Luckily, we can adjust eye sensitivity by using filters, like the ones used for watching a solar eclipse, to avoid the light saturating the cones in our retinas (and ultimately burning them).

Which is what we're doing with stars. To show you the shifting patterns of the granules on their surface. To let you see flares, impacts, differences between star classes.

If you'd like an even more in-depth explanation, visit

http://www.vendian.org/mncharity/dir3/starcolor/

And stay tuned for more star display modes to come, ultimately we want to show what they look like in different spectra, and add some more eye candy too :)

- Georg

P.S: It's completely impossible to compare colors of digital images with someone else as long as your monitor and the monitor of the user you're comparing it with are not calibrated to the same specs! For one user the sun in the image posted above may look yellowish, blueish for another, both may have different impressions of contrast and brightness... so expect and accept to disagree on colors ;)
Title: Re: G Type stars like Sun should have snowwhite color instead of yellow
Post by: gabriel.dac on November 05, 2014, 10:49:36 AM
P.S: It's completely impossible to compare colors of digital images with someone else as long as your monitor and the monitor of the user you're comparing it with are not calibrated to the same specs! For one user the sun in the image posted above may look yellowish, blueish for another, both may have different impressions of contrast and brightness... so expect and accept to disagree on colors ;)

This reminds me of that old "is your red the same as my red?" philosophical discussion.... :)

And stay tuned for more star display modes to come, ultimately we want to show what they look like in different spectra, and add some more eye candy too :)

Oh nice. That's what I suggested my thread: http://universesandbox.com/forum/index.php/topic,14047.0.html

I suggested Infrared and Ultraviolet visualization modes (along with Realistic, Mass, Velocity, etc...) to be included. With infrared vision, for example, you'd be able to see hot objects that aren't hot enough to glow in visible light. A tutorial on blackbody radiation would be great too
Title: Re: G Type stars like Sun should have snowwhite color instead of yellow
Post by: Gordon Freeman on November 05, 2014, 10:52:33 AM
kol more spectra? yes please
Title: Re: G Type stars like Sun should have snowwhite color instead of yellow
Post by: Cryo on November 05, 2014, 04:30:36 PM
Will there be those strange deformed stars with massive
Title: Re: G Type stars like Sun should have snowwhite color instead of yellow
Post by: Gordon Freeman on November 06, 2014, 06:06:45 AM
You mean Space Engine red supergiants? I doubt how that's how they look IRL...
Title: Re: G Type stars like Sun should have snowwhite color instead of yellow
Post by: Lord DC on November 06, 2014, 08:00:32 AM
You mean Space Engine red supergiants? I doubt how that's how they look IRL...
yeah, to me they look like giant molten cheeseballs
Title: Re: G Type stars like Sun should have snowwhite color instead of yellow
Post by: BrandCollision on November 13, 2014, 05:28:35 PM
You mean Space Engine red supergiants? I doubt how that's how they look IRL...
yeah, to me they look like giant molten cheeseballs
LOL! ikr!
Title: Re: G Type stars like Sun should have snowwhite color instead of yellow
Post by: smjjames on November 13, 2014, 08:11:57 PM
You mean Space Engine red supergiants? I doubt how that's how they look IRL...
yeah, to me they look like giant molten cheeseballs
LOL! ikr!

They're probably highly exaggerated.

Still though, while there are some red giant stars already in Ubox, Sol doesn't actually go through the red giant phase yet. It does get a bit bigger and a little redder, but it's far from swallowing up mercury, let alone venus and potentially earth.
Title: Re: G Type stars like Sun should have snowwhite color instead of yellow
Post by: DiamondMiner10 on November 14, 2014, 08:48:02 PM
My opinion is (this has probably been said before) the stars are way too bright. All of them look white to our eyes, its just that if you put the stars really far away they looked colored. The sun is that color, but anything really really bright looks white to us.