Celestia 1.3.2 pre 10

[chris]

A new Celestia prerelease package for Windows is available. 1.3.2 pre 10 will probably be the last prerelease before 1.3.2 is finally done. It's available in the usual place:

http://www.spacesim.net/prerelease/cele ... 2pre10.exe

There's no EXE-only package for 1.3.2pre10 because so many of the data files have changed since the last prerelease. Here's a summary of the changes:

* Implemented an algorithm for importance weights to avoid overlapping or
too crowded location labels for Mars, Venus and the Moon
* Added new textures for Titan based on recent imaging from the Cassini mission
* Improved depth sorting so that hidden surface removal works properly for overlapping objects
* Added theoretical estimates of oblateness and rotation rate for extrasolar planets
* Replaced old Io and Europa textures with improved versions
* Added disposition modifier for ssc objects to control what happens when an object with the same name and parent already exists. The three possible behaviors are Add (the default), Replace, and Modify.
* Fixed several mesh rendering bugs

--Chris

[symaski62]

moi travaille

tout de monde => http://cvs.sourceforge.net/viewcvs.py/c ... te#dirlist


celestie 1.3.2 pre 8


tout fin


/symaski62

[Rassilon]

Chris,

Very nice job on Titan! It looks like one of my phantasy worlds with the thick atmosphere...And the improvements on atmospheres and haze with FX is simply superb...

Models render good and everything seems tip top...I havent found any errors yet anyway...

Cheers!

[don]

Pre 10? Guess I was asleep when Pre 9 was released? Don't recall seeing it. Talk about time flying!

[fsgregs]

Chris, could you post a short explanation of how to use "Add, Replace, Modify" in an ssc file, or direct us to a thread that might already describe it. I am anxious to learn how to use it. A VERY useful feature.



Frank

[selden]

Well, I'm not Chris, but... the descriptions of how the new "disposition" modifiers work haven't really been gathered together until now. They've been in the form of changes to changes to changes. It took some discussion before they were finalized.

Here's a description that I've put together from messages by Harald and Chris on the developers' mailing list.

When a new SSC object is defined with the same name as an existing object but with no dispostion modifer, Celestia just adds the second object to its internal list using that same name. This makes it impossible to reliably change or replace default objects by files in /extras/. This is the way it's always been.

You now can define an SSC object with the same name but with a disposition modifier which controls how the new and original objects are handled by Celestia.

The three modifiers are Add, Replace and Modify.

Add
acts the same as no modifier: the new object is simply added to the list of objects known to Celestia. Any confusion caused by the use of the same object name more than once is still ambiguous.

Replace
causes the new object to completely replace the preexisting object of the same name. It's as if the previous object definition had not been read in.

Modify
causes any characteristics defined in the new object to replace those same characteristics in the old object definition. Characteristics which are not mentioned in the new object are left unchanged.

Here's an example:

Code: Select all

# This gives the earth a seoond moon.
# Both are named "Moon"
# but this second Moon has somewhat different characteristics from the first Moon.

Add "Moon" "Sol/Earth" {
    Texture "moon.*"
    Radius 1737
    EllipticalOrbit {
        Period 27
        SemiMajorAxis 384400
        }
}

# this replaces Phobos by something quite different
# the original tiny Phobos is gone.

Replace "Phobos" "Sol/Mars" {
    Texture "moon.*"
    Radius 1737
    EllipticalOrbit {
        Period 27
        SemiMajorAxis 384400
        }
}
     
# This simply makes Deimos bigger.
# It still follows the same orbit and looks the same.

Modify "Deimos" "Sol/Mars" {
    Radius 1000
}


Note:
I haven't tried using either Replace or Modify when there already are several objects of the same name, so I don't know what will happen. It's still confusing

[alphap1us]

Could someone explain how Celestia determines which is the old and which is the new object? Obviously, something in the extras directory could modify a default object, but what if I had two objects that were both trying to modify the same object (or each other)? Which one takes precedence?

[Harry]

AFAIR there is no defined load-order for ssc-files, so the only guarantee is that ssc-files in extras replace/modify definitions in the default data directory.

There is a shortcoming with Replace: the new object will be added to the end of the list of children, i.e. if you use Replace with Earth, Earth will no longer be the third planet in list and when using the number-keys to select planets.

Harald

[don]

Why? If it's a Replace operation, then why can't the BASE definition ("Earth/Sol") remain in-place (so the position values do not change) with only the details being changed?

[don]

A new Celestia prerelease package for Windows is available. 1.3.2 pre 10 will probably be the last prerelease before 1.3.2 is finally done.

Chris, please remember to change the Help / About version from 1.3.1 when you do a final build.

[Harry]

Why? If it's a Replace operation, then why can't the BASE definition ("Earth/Sol") remain in-place (so the position values do not change) with only the details being changed?

The current implementation deletes the old definition, then adds the new one - which adds to the end of the list. A fix for this is on the way...

Harald

[Rassilon]

This could come in handy if you wanted to create the stages of a star from proto to black hole....Along side the timestamp function used in ssc files...of which I cannot remember offhand what that command is named...

[RND]

Cant wait for it to go final. I have one suggestion Id like to see though. The option to change the temporature of a Sun or planet. K doesnt mean a great deal but celsius would.

[John Van Vliet]

k --kelvin is celsius--


k= temp(in celsius) +273 deg. celsius

70 deg. celsius = 343 k

[jestr]

Using the Replace,add,modify commands,would it be possible (as Runar is trying to do-see this threadhttp://www.shatters.net/forum/viewtopic.php?p=39944#39944) to have a spacecraft moving from an xyz defined orbit (which has the craft entering the star system and moving towards an inner planet) to take up an elliptical orbit around this planet.I can't see how to use these commands to change from (in this case)
"Orion Rocket" "Ran"
to "Orion Rocket" "Ran/Hroenn"
where Ran is the name of the star and Hroenn is the planet.
Just what does Celestia, Replace?
is it simply"Orion Rocket" or does the rest of the definition have to be the same also?Is there some combination of these commands which would acheive the desired result?
All the best Jestr

[Rassilon]

Fridger,

Very nice job on Titan! It looks like one of my phantasy worlds with the thick atmosphere...

Chris,

The improvements on atmospheres and haze with FX ( I was foiled again) is simply superb...

Models render good and everything seems tip top...I found a few errors but bloody hell its all for fun!

Cheers!

Fixed

[don]

The current implementation deletes the old definition, then adds the new one - which adds to the end of the list. A fix for this is on the way...

Excellent!

[maxim]

Using the Replace,add,modify commands,would it be possible to have a spacecraft moving from an xyz defined orbit (which has the craft entering the star system and moving towards an inner planet) to take up an elliptical orbit around this planet
....
Is there some combination of these commands which would acheive the desired result?

As I understand, these commands are applied at load time not at run time, so they won't help you of anything that should change dynamically in celestia. Theyr'e just for maintaining your own celestia installation.

maxim

[jestr]

Would it be possible to make these commands time dependant,so one defined object could totally replace another using Beginning and Ending commands,Jestr

[maxim]

Shouldn't this be possible already?
Just set the beginning time of your new object equal to the ending time of your old object.

Well of course I don`t know about the browser entries.

maxim