Grant, small request

Tips for creating and manipulating planet textures for Celestia.
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Darkmiss
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Grant, small request

Post #1by Darkmiss » 08.02.2004, 12:01

Hello Grant
On the textures forum i see lots of textures by different people
and most of the time they seem to be rotated diferently from one another.

there ssem to be lots of different Jupiter textures and venus textures
and hardly any match up.

So I thought, been as you seem to know more about this than most.
would it be possible for you to make a small sticky post.
showing small thumbnail pictures or the correct planets rotation for textures, for Celestia :?:
Maybe you could start with just the main planets, then add asteroids and others later :?:

just so we have a refrence to stick to, to make thing consistent.

I hope I'm not asking to much. :?:
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jestr
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Post #2by jestr » 08.02.2004, 12:21

The textures you get with the install of Celestia are the correct orientations Paul just match your new ones up with those.Cheers Jestr

granthutchison
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Post #3by granthutchison » 08.02.2004, 15:18

Jestr's right - the information is all there in Celestia itself. It's just that some texture makers aren't particularly interested in making their textures match up.

Grant

Bob Hegwood
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Re: Grant, small request

Post #4by Bob Hegwood » 08.02.2004, 15:41

Darkmiss wrote:Hello Grantthere ssem to be lots of different Jupiter textures and venus textures and hardly any match up.


Paul,

This is something that I asked about in another thread too. The problem with textures like Venus and Jupiter is that there is no Central Meridian definition for use by the Celestia community. In other words, planets having a fixed reference point on the ground can be set up so that the Central Meridian (0 degrees longitude) is defined as being in the exact center of the image.

With Jupiter and Venus, however, there is no FIXED reference point which can be used to identify a Central Meridian location. Thus, you're going to find textures which define 0 degrees longitude at almost *any* place on the map.

As Grant suggested to me in another thread, the only thing we can really do to correct textures for planets like Venus and Jupiter, is to compare any new textures with the original Celestia textures, and then move the Central Meridian location so that it matches up with the location *currently* used by Celestia.

Have I gotten that right, Grant?

At any rate, that's my understanding of the problem. Not too many texture makers are going to go to that much trouble though. It takes a bit of work to first determine where the Central Meridian is located in the Celestia image, and then to move it to the same location in any new texture image.

Hope that helps.

Take care, Bob
Bob Hegwood
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granthutchison
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Post #5by granthutchison » 08.02.2004, 16:22

Bob:
I think Darkmiss may have been referring to the surface texture of Venus, which does have a well-defined prime meridian. There seem to be a host of Venus surfaces add-ons out there that don't align with Celestia - all of them very clearly derived from a small number of originals available on the web. For Venus clouds it doesn't really matter, since there are no permanent features to worry about. For the gas giants, there's no unique meridian because everything drifts relative to everything else - but Celestia is tweaked to display the Great Red Spot in its correct current position, so it would be nice if add-on makers offset their Jupiter textures to bring the spot into alignment with the Celestia original. But if they don't, it's the work of a moment to fix their texture yourself in an image editor.

Grant

Topic author
Darkmiss
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Post #6by Darkmiss » 08.02.2004, 18:22

The problem is I havent seen the original textures for Celestia for a long time.
as soon as a large high quality texture is available, that becomes my delault texture, and in the bin goes the old one

But im not asking this for myself
as my skills as a texture creator, are virtually zero
but as i said there are a lot of other that could do with this information.

because the proof is out there, all these mismatched textures proves
this kind of refrence could be handy.
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granthutchison
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Post #7by granthutchison » 08.02.2004, 18:31

Darkmiss wrote:all these mismatched textures proves this kind of refrence could be handy.
I'm afraid it just proves that a lot of people aren't that interested in getting their textures aligned in Celestia. It's their choice, after all. And to be frank, if they can't be bothered to do the very obvious thing of checking against the original Celestia textures, I don't anticipate they'll have the energy to go looking on the forum.

Grant


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