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Stellarium / stellarium

Stellarium is a free GPL software which renders realistic skies in real time with OpenGL. It is available for Linux/Unix, Windows and macOS. With Stellarium, you really see what you can see with your eyes, binoculars or a small telescope.
https://stellarium.org
GNU General Public License v2.0
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Corona texture not adjusted for refraction #2264

Open Atque opened 2 years ago

Atque commented 2 years ago

Viewing solar eclipses close to the horizon, we see that the corona texture is not affected by atmospheric refraction. See the screenshot below.

stellarium-117

Note how the Moon is squeezed while the corona texture is not, creating an ugly artifact.

worachate001 commented 2 years ago

I'm not sure this can be considered as a fix or not. I just try to make it better by editing the images (not sure this is allowed for image's owner) and adjust the size of corona.

corona

The process make it looks like this for 1957-10-23 total solar eclipse.

1957-10-23-tse-fix

gzotti commented 2 years ago

No, please don't paint the corona. It is pixel-perfect from the 2008 Mongolian eclipse. What we need to do is adding refraction to the corona texture. Currently it is drawn as simple image that only can be rotated, but not squeezed by-vertex. (I.e. use VertexArray for it.)

Atque commented 2 years ago

I just noted that the texture is not aligned with the ecliptic, at least if the eclipse is high in the sky. Look at the July 5 2168 eclipse (from the location of maximal eclipse), and note how the texture rotates as you pan around. It should be fixed.

gzotti commented 2 years ago

Yes, when somebody will implement it in a technically fully different way than it is done right now (DSO-like vertex array, not rotated image), this will likewise be fixed.