New star textures

[Kreso]

Hello.

One of the new features in Celestia 1.5 is the option to change the textures of stars globally. So, here is my work in progress:

http://kcindric.fizika.org/data/kc_stars.jpg

I would appreciate any comments, constructive criticism, suggestions...

I have been using Celestia for many years, but just recently I became interested in trying to improve it and explore the possibility of creating add-ons... Here are some of my thoughts: I have no plans to create fictional (sci-fi and such) content, except by adding artistic (hypothetical) content which I would like to make as accurate as possible (scientifically).

As it is possible to change textures of stars, is it possible to change 3D models, or is that hard-coded in Celestia? I would like to add solar flares to all F, G and K type stars, large flares to carbon stars (class S, N and R) and small nebulae of ejected material around Wolf-Rayet stars (WC and WR class).

Kreso

[NIGHTCAST2000]

Hi Kreso,
I think your star textures look very nice! my only suggestion is that since it is work in progress,I would make the stars more granular-looking.
But all the same,keep up the good work.

Regards,
NIGHTCAST2000

[d.m.falk]

You might want to make Betelgeuse more like your HIP 94706, although even more pronounced-- Betelgeuse, being the first exosolar star ever to be directly imaged with distinct stellar features, has FRIGGIN' 'UGE convection currents, enough that parts of the star appear very dim and parts very bright, and resembling large scale bubbles.

d.m.f.

[Kreso]

Thank you for the comments.

I intentionally didn't want to make stars very granular-looking, because stars are very bright objects, so I feared too much granulation would make them appear not as bright as they should. Also, those massive O, B, A and F stars have their radiative zone over the convective so I guessed they would not appear with any granulation at all. Perhaps I'm wrong... I am not sure that such stars even have spots on their surface. Hopefully someone here will shed some light on this issue.

I wanted to make the Sun much less yellow (than in official distribution of Celestia), because, apparently it is white when viewed from outside the Earth's atmosphere.

Since this project is far from being complete, I wanted to compensate high granulation of Wolf-Rayet stars with the small nebula of ejected material. This "granulation" is only here to make them appear very active and dynamic.

Concerning red supergiants like Betelgeuse, and red dwarfs like Barnard's star, there is a problem because they are both class M, so they use the same texture. So, if I made Betelgeuse more turbulent and "dynamic"-looking, than all red dwarfs would look like that, and I guess they are not as active and turbulent. I guess red dwarfs should have more granular-looking surface because they are not as bright. If only it would be possible to modify actual 3D models of stars, globally (it would be quite a job to alter every single star in Celestia) - then I would add large flares and similar dynamic elements to stars. If anybody has an idea, please post here.

I will consider making textures of M class stars more "dynamic"-looking. Should I make them more orange in appearance? That was the idea, but these stars in Celestia have a pink glow around them, so that didn't look very nice. Stars are, more or less, black bodies, and pink is not a color of a black body. Perhaps there is a way to tweak this glow, but I don't know how to.

Also, about neutron stars... I have no idea what would they look like up close. Since they are VERY hot, they should be white/blueish in appearance. And since there are very strong magnetic fields there, perhaps they have a lot of darker spots? Do they, in general, have any distinct surface features?

I want to make this as realistic and scientifically accurate as possible (concerning color and surface features), so, please, feel free to criticize me (constructively) as much as you want. Any help, comment, or advice is highly appreciated.

Kreso

[duds26]

Neutron stars twist also very rapid around their center.

Best thing you can do is first read a lot and think about information about stars.

What happends with them during their existence?
What elements can be formed and what is their impact on temperature and appearance of the star.
How does the movement of the star has an impact on it's appearance.

The sun is one star where you can collect data from it's appearance almost directly since it's so close.
So you wanna also observe the sun's appearance in pictures.

Visit the motherload to look at the other addons made for stars like Chams magnetic field addon and others.

(It's usefull to dive in a little bit of particle physics since stars are powered by nuclear reactions and neutron stars are well..eh very big nucleus that are normally very small when they are with a few and form a core, nucleus of an atom)
(A little far farfetchet, if you know physics try to do some physics experiments on the computer to simulate what happends in stars.)

Here is a picture of the sun meant for looking at with stereoglassees (red and blue)

ZonStereoview_PIA09321.jpg

[fsgregs]

Kreso:

I like your star textures. Will you be posting them with example stc files for the community to use?


Frank

[Kreso]

Kreso:

I like your star textures. Will you be posting them with example stc files for the community to use?


Frank

Thank you, I'm glad you like them.

I can upoad them, sure, but they are far from being finished and, at this stage, are not very good at all (low quality). But I think the colors are quite good now, except, I would like to make M class stars more orange (i.e. more black-body-like) - but, there is no point in doing that if it is not possible to change their glow color.

Here is the link: http://kcindric.fizika.org/data/kc_stars.zip Enjoy.

Kreso.

[Joey P.]

I have gotten used to using these textures. Thanks

[John Van Vliet]

month shy of 10 years

a bit back i posted a few sol textures here
http://forum.celestialmatters.org/viewtopic.php?f=4&t=466

[callix]

Great improvement from 10 years back.

[Joey P.]

The image is not available, but for some reason, I found it on a wiki site about some cringy kid's show on YouTube...
How did it get there? Here it is: https://vignette.wikia.nocookie.net/battlefordreamisland/images/4/4b/KC_Stars.jpg


Also, I found some models on the Sketchup 3D warehouse that plagiarize your star textures! However, since you are planning to add solar flares to type F, G and K stars, you could use these as inspiration, since the creator of the model used your textures to make solar flares. Here they are: https://3dwarehouse.sketchup.com/user/1371005398273822518935928/joshua?nav=models

[Joey P.]

You can use the solar flares in Runar Thorvaldsen's A portrait of our sun addon, since the color fits widely with type F, G and K-type stars.

[Joey P.]

Besides, Betelgeuse is no longer the only star that is directly imaged. Vega, Algol, XX Trianguli, and Antares have all been imaged as well. Is it possible to make their glow color more vivid, like as seen in the images? I can prepare the .stc file, but I think you need to modify the models used for the stars to modify the glow colors.

BTW, I like your star textures, and I have used them in my Celestia along with viewtopic.php?f=23&t=17804.

[Danny Lorraine II]

those star textures are so good . i've downloaded them all for my celestia .

[Danny Lorraine II]

i also have textures for the largest stars as i have stated in another thread

[SpaceFanatic64]

Removed at the request of the author.
Moderator

[Joey P.]

Concerning red supergiants like Betelgeuse, and red dwarfs like Barnard's star, there is a problem because they are both class M, so they use the same texture. So, if I made Betelgeuse more turbulent and "dynamic"-looking, than all red dwarfs would look like that, and I guess they are not as active and turbulent. I guess red dwarfs should have more granular-looking surface because they are not as bright. If only it would be possible to modify actual 3D models of stars, globally (it would be quite a job to alter every single star in Celestia) - then I would add large flares and similar dynamic elements to stars. If anybody has an idea, please post here.

I will consider making textures of M class stars more "dynamic"-looking. Should I make them more orange in appearance? That was the idea, but these stars in Celestia have a pink glow around them, so that didn't look very nice. Stars are, more or less, black bodies, and pink is not a color of a black body. Perhaps there is a way to tweak this glow, but I don't know how to.

The upcoming version of Celestia features a now orange glow and texture for type M stars and Frank Gregorio has created "calmer" red dwarf textures (for Gliese 581 but you can extend it to Proxima Centauri, Wolf 359, and TRAPPIST-1) that are available on the Celestia motherlode.

[Joey P.]

I also remembered someone made a texture and mesh for Betelgeuse that was derived from an actual simulation. If you search up "Category:Celestia" in Wikimedia Commons then I think you will find it. And yes, I am looking for something like that, too.

Added after 50 seconds:
If Celestia will separate Be stars from type B stars (which I would like to see), then they would deserve a separate texture.

[Joey P.]

Kreso wrote:
Perhaps I'm wrong... I am not sure that such stars even have spots on their surface. Hopefully someone here will shed some light on this issue.

O, B, and A stars lack outer convective zones - they lack sunspots.

Additionally, the classification "Q" was originally used by Annie Jump Cannon for all miscellaneous/peculiar spectra, though today I have seen it in use for only neutron stars, just like Celestia. However, I think it is formally used for novae.

[Joey P.]

Here is a zip of all the star textures, including a nebula texture. I hope you do not mind.