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List of impossible add-ons

Posted: 21.04.2021, 18:20
by john71
Are there any add-ons which cannot be realized in Celestia 1.6.2.2?

It seems that in the last 20 years every possible idea surfaced...

Or am I wrong? :think:

Posted: 21.04.2021, 18:56
by SevenSpheres
List of things that (as far as I know) are completely impossible in Celestia, even with workarounds, scripting, etc:

  • A file that completely removes an object defined in another file.
  • Stars with impossible colors, like green or purple (there are workarounds for this, but none that change the actual glow color of the star).
  • Anything that involves stars changing over time, since unlike ssc and dsc objects, it's impossible to make a star invisible, even using a script.
  • Stellar proper motion, and motion of DSOs.
  • Stars farther than the render limit (10 million light-years for 1.6, or 1 billion light-years for 1.7).
  • Objects with both LunarLambert and a SpecularTexture.
  • LunarLambert for clouds.
  • AltSurfaces for clouds, stars, etc.
  • Gravitational lensing.
  • Objects smaller than ~1 cm.
Will update if I think of more.

Posted: 21.04.2021, 19:40
by john71
Whoa, very nice list.

You can have strange colored stars, but without the glow:

strange sun.png


You can have very small objects, but Celestia won't show them, only as a point.

Posted: 06.06.2021, 01:05
by Eric Nelson
I made an addon for V838 Monocerotis as a binary system based on studies.
1 M-type red supergiant and 1 B3-type main sequence star.
I even made a custom texture for V838 Monocerotis A from scratch (using paint.net) as many view it (a bright magenta star) and while the glow around it isn't affected, it looks goos with it.
The spectral type, magnitude, luminosity, temperature and radius for it was based off of gironde's addon of largest stars https://celestia.space/forum/viewtopic.php?f=23&t=19624&p=141067&hilit=proxima+centauri#p141067
Which simulates the star much more accurately than Meegja's V838 Monocerotis Nova addon from the Celestia Motherlode, which simulates it as an unrealistically smaller K star (along with an unrealistically flat billboard model of the nova with some bumps and a highly outdated image).
Though it doesn't simulate V838 Mono as a binary system which it is (a red supergiant and main sequence star) and what my addon of it is.

Posted: 06.06.2021, 14:52
by SevenSpheres
Eric Nelson wrote:I made an addon for V838 Monocerotis as a binary system based on studies.
1 M-type red supergiant and 1 B3-type main sequence star.
I even made a custom texture for V838 Monocerotis A from scratch (using paint.net) as many view it (a bright magenta star) and while the glow around it isn't affected, it looks goos with it.
The spectral type, magnitude, luminosity, temperature and radius for it was based off of gironde's addon of largest stars viewtopic.php?f=23&t=19624&p=141067&hilit=proxima+centauri#p141067
Which simulates the star much more accurately than Meegja's V838 Monocerotis Nova addon from the Celestia Motherlode, which simulates it as an unrealistically smaller K star (along with an unrealistically flat billboard model of the nova with some bumps and a highly outdated image).
Though it doesn't simulate V838 Mono as a binary system which it is (a red supergiant and main sequence star) and what my addon of it is.

This has very little relation to this thread's topic. You're aware you can make new threads, right?

Posted: 06.06.2021, 15:01
by trappistplanets
SevenSpheres wrote:This has very little relation to this thread's topic.

i agree this is about impossible addons, not stars

Posted: 06.06.2021, 18:21
by Eric Nelson
The part is about the star color and V838 Monocerotis appearing magenta which seems surreal (and impossible to some) actually but stars have colors.
Now an impossible addon to make is a star with Earth's continents or any terrestrial landscape on the surface along with life on such.
Stars are too hot to live on and are made of hot gases and plasma.
But all in all, a magenta star's impossible as far as we know.

Posted: 06.06.2021, 18:45
by SevenSpheres
Eric Nelson wrote:The part is about the star color and V838 Monocerotis appearing magenta which seems surreal (and impossible to some) actually but stars have colors.

Sure, it's tangentially related to the topic, but your post wasn't about impossible addons or making stars that glow magenta, it was about making an addon for V838 Monocerotis. It's too far off topic and should have been posted in its own thread.

Eric Nelson wrote:Now an impossible addon to make is a star with Earth's continents or any terrestrial landscape on the surface along with life on such.
Stars are too hot to live on and are made of hot gases and plasma.

That's certainly unrealistic, but not impossible to render.

Posted: 06.06.2021, 18:54
by Eric Nelson
Of course, thanks for the information.

Posted: 07.06.2021, 00:53
by trappistplanets
SevenSpheres wrote:That's certainly unrealistic, but not impossible to render.
yeah

Eric Nelson wrote:Now an impossible addon to make is a star with Earth's continents or any terrestrial landscape on the surface along with life on such.
you can change the texture of the star in the code as you were doing here, viewtopic.php?f=5&t=21181
but instead of changing the original star texture to a costume star texture, you can change the original star texture to a texture of a planet like earth as shown in seven's pic https://cdn.discordapp.com/attachments/5586434404 ... 028481917091881/SpicaPoles.png

Posted: 07.06.2021, 03:34
by Eric Nelson
Yeah, and the point is in reality, it would be impossible for a star to look like a terrestrial planet unless the mass is reduced and density matches that of a terrestrial.
Yet in reality, we can't turn a star into a terrestrial planet and not change its mass, size or density.
Yet in reality we don't even have the technology to convert Sol or any star into a planet or such as they're part of nature and nature always wins.
Yet an Earth sized object with 1 Solar mass would quality as a white dwarf which certainly wouldn't look anything like Earth.
And if Earth were a star, the 1st thing that would happen is everything including us would burn up and stuff.
Such an addon would be good for fictional purposes only.

Posted: 07.06.2021, 04:03
by DaveBowman2001
Eric Nelson wrote:Yeah, and the point is in reality, it would be impossible for a star to look like a terrestrial planet unless the mass is reduced and density matches that of a terrestrial.
Yet in reality we don't even have the technology to convert Sol or any star into a planet or such as they're part of nature and nature always wins.
Yet an Earth sized object with 1 Solar mass would quality as a white dwarf which certainly wouldn't look anything like Earth.
And if Earth were a star, the 1st thing that would happen is everything including us would burn up and stuff.
Of course Celestia's photo and code based and not meant to simulate gravity like Universe Sandbox or other gravity simulators.
Such an addon would be good for fictional purposes only.

Um no, the point of this thread is to identify which addon cannot be rendered in any way within the technical capabilities of Celestia 1.6.2, not the laws of physics preventing such things to exist. Your recent posts (except like simulating gravity yes) are still possible to code in Celestia, just classified as fictional :smile:

Posted: 07.06.2021, 04:49
by Eric Nelson
Yup, and we can't make an addon where an object classified as a planet, Moon or spacecraft would have a spectral type or apparent magnitude like a star would.
Celestia wouldn't render the planet, moon or spacecraft like that.