The Feature Requests Collecting Thread

[MibTaz]

Hi all

I have an item to add to the list, it's for using 3rd party libraries from Celestia.

http://celestiaproject.net/forum/viewtopic.php?p=67361

Thanks for a great app

[kanthoney]

I'd like a "lost in space" feature. I want to imagine that my experimental hyperdrive has gone wrong and tossed me a few hundred light years into space. I've fixed the fault but now, armed only with a bunch of Earth-based star data and my trusty sextant, I've somehow got to navigate my way back home.

So, I guess what I'm looking for is a tool to measure the angular distance between two stars, implemented in such a way as to not tell me anything else about the two stars.

BTW, the version of Celestia that I'm currently using (1.4.0, GTK+ front end) marks a random point in space about 200AU from the sun when it's not marking anything else. Is there any way of getting it to stop without disabling markers entirely? It's telling me exactly which direction "home" is, and I don't want it to.

[matthiasfw]

I would like to see an option that will translate the observer's speed from smaller to larger units, rather than having the program do it automatically.

For instance, if the observer's current speed is 1 C and I accelerate it to a high multiple of C, I want the ability to lock in the unit at C so it doesn't automatically start expressing the velocity in AU/second. If the observer is moving at a few hundred C, I want to be able to even change the unit of velocity to km/second if that's what I want.

Of course, the use of exponential numbers will be required for very large numbers but if someone wants to leave it on automatic (that is, the way it works now), they should be able to do that too.

Basically, if I want to have a cruise through near-solar space at 10,000 c, I would like to know that I'm going /at/ 10,000 c instead of digging out my calculator and pegging the velocity at its equivalent in AU/sec.

[Chuft-Captain]

I'd like to see the ability to define halo-orbits.
There are stable halo-orbits around the L4 and L5 libration points, which I'd particularly like to model, but I don't think they conform to the classical definition of a Keplerian orbit.
Here's what I've been able to find out so far:

from: http://kosmoi.com/Science/Physics/Mecha ... 3.shtml#m7
LIBRATION POINTS, HALO ORBITS, & MANIFOLDS
... A halo orbit is an N-body problem, involving interactions between the probe, the Sun, and the Earth. Early calculations of halo orbits involved making educated guesses, running them through a software simulation, and then using the result to get a better guess.
This approach was workable but crude. In the 1990s, improved software was developed that essentially mapped out entire ranges of three-body trajectories, known as "manifolds". Paths known as "dynamical channels" can be identified on the manifolds that chart out the course a spacecraft would follow on its own after given an initial push, analogous to the way a ball bearing would meander about on an uneven surface after being given a nudge one way or another...

From: http://www.rfreitas.com/Astro/SearchIcarus1980.htm

[jesus_barradas]

Sorry my ignorance. I have tried to find the Canadian satellite Radarsat-1 and 2, but haven??t found it anywhere. Plus, i dont understand the parameters in the orbital carachteristics of this satellite.

RADARSAT
1 23710U 95059A 06045.80701963 .00000104 00000-0 57429-4 0 5970
2 23710 98.5767 54.1682 0000951 79.5677 280.5607 14.29985386536680

I dont know what this number are and how can i use them to determine the orbit of the model in the program.

If anyone can help me ...i??ll appreciate.

[selden]

That is a "TLE" format of orbital parameters, short for Two Line Elements. I'll leave it to you to look up the details.

A spreadsheet that converts TLEs into Celetia's SSC format is available at
http://www.lepp.cornell.edu/~seb/celest ... ets.html#3

[selden]

It would be extremely useful if "GoTo Surface" (Ctrl-G) could be made to work with Mesh objects, so that the viewpoint was from the first intersection with a surface of the model.

One application for this would be to generate reasonably accurate "line of sight" viewpoints of satellites in low earth orbit when using a 3D model for the Earth's surface instead of the default spheroid.

[lacy]

I don't know if this has ever been discussed or if it is even possible, but my idea is to have Celestia linked up in some manner to these databases like NASA and have the ability to automatically update itself with any new discoveries that way. I would not even begin to know how this would be accomplished. It would be nice since we would instantly be able to view new and surprising things without having to search everywhere for an add-on that may not be entirely accurate. I say this from a standpoint of wanting realtime information and accuracy in data that may unintentionally be converted incorrectly.

I have to say that most add-on developers do a wonderful job at making sure that their data is a accurate as possible and in no way am I trying to minimize their contributions to the communicty, but I would like for this function to be automatic somehow.

Thank you for listening to my suggestion

Lacy

[gandalf]

If possible, it might already be possible, I would like to see a "four - sixths of a box" output on 4 monitors. I am researching the building of a mobile geodesic dome planetarium that would go around to area grade schools. I have seen many schemes for getting a wrapped / warped image on the surface of a dome. I have seen $17,000 + (USD) fisheye projectors that have a single 1024 x 768 rez projector in them. I don't have that kind of money and was looking at going a different route.

I am planning on a dome with 4 "inexpensive" 800 x 600 projectors showing 4 sides - front, left, right, and top - four sixths of a box onto the walls of a dome. I see that Celestia can be spread out over multiple monitors. This would take care of 3 of my 4 sides - left, center, and right - which in-and -of-itself is a great thing. But I would like that "top" output for a more complete "planetarium" use vs. a "spaceship" look with 3 large "windows" surounding the kids. The problem with the "top" is that 3 of the edges must match one edge of each the three other outputs. Any thoughts would be most welcome.

Many thanks!

[buggs_moran]

Have you seen this gandalf?
http://astronomy.swin.edu.au/~pbourke/projection/domemirror/

[gandalf]

buggs,

Many thanks for the link but, yes, I have seen and studied that approach from that exact website. It seems like a good thing. I was initially enthusiastic about that approach and said to myself - "That's the way to do it!"
I am currently looking for other ways.

The domemirror method is very viable - except for the elusive "warping" software needed. I have not yet found anything that would warp another running program in real time. My humble apologies but I am not much of a programmer. I did find FULLDOME software - an Adobe plugin that would warp movies, but not in real time (that I know of.)

Then, try running a commercial DVD or other video during the presentation - this could only be done with a second projector pointing striaght at a wall to give a non-warped viewable image. So now I need at least 2 projectors.

I am still looking at possiblities, but soon I wish to make the move, get the funding, buy what is needed in a knowedgable manner, and start showing kids the larger world, or space, around them. I am a science teacher and will experiment with the different setups until I find something that I know will work - not just for me but for some other teacher that needs to use the equipment. Celestia is a great program that seems to fit my requirements without the need for immediate modifications. Using mirrors would require an immediate modification that is not currently available.

Again, Thank you.

[Anarki]

Hello.

I'd like to ask the author to realize atmosphere transition and darkness during solar eclipses, when shadow of the moon falls on the planet.
In this case ground goes dark, but sky remains blue.

Please, see this topic for details.
Atmoshpere isn't dark during Solar Eclipse. Why?

Thanx.

[gandalf]

I guess I need to remove my previous request for the 4/6ths of a box option because celestia already can do exacly that using frames. But I will respectfully request that in the view menu, a checkbox be added that makes all the frames follow motion commands as well as time commands. A simple example that would make use of this would be a rear view mirror in the form of a small frame that has the camera pointed backwards. Right now, if you move the main frame, the "mirror" would get left behind. I am certain that this synched motion could be done with a script, and I would appreciate a nudge in the right direction as far as what that script might be, especially if the motion commands are from the keyboard / mouse / joystick and not scripted themselves.

Many Thanks!

[trgoodson]

Request for JPL/NASA SPICE Library: http://shatters.net/forum/viewtopic.php?p=70674

see also http://shatters.net/forum/viewtopic.php?p=70730
and http://sourceforge.net/tracker/index.php?func=detail&aid=1477835&group_id=21302&atid=121302

[t00fri]

Request for JPL/NASA SPICE Library:
...

trgoodson,

what is the total size of the whole lot? How do you think
would it enlarge the size of a generic Celestia
distribution? How would people without or with poor
internet access make use of Celestia with SPICE?
Since SPICE is not usually part of Linux distributions,
how did you imagine people would incorporate the
SPICE package in /practice/ (without knowing anything
about compiling etc) .

Did you examine, for example, whether the resulting
planetary orbits from SPICE are really more accurate
than what we get from VSOP87. I simply doubt it. We
have tested a huge number of delicate events e.g.
among Galilean moons and moons of the outer planets
with spectacular results.

Did you estimate for example, how the incorporation of
the SPICE lib would slow down the required extremely
high performance of Celestia?

Proposals like yours should always be backed up with
some concrete estimates along the lines I was
indicating above.

Bye Fridger

[mpiva]

Request for setting a distance limit to visible stars, sort of like the "Filter Stars" setting under "View Options" but based upon the selected object, NOT the camera position. I want to be able to say "Show all stars within 25ly's of Rigel" and then zoom out and look at that group of stars from afar. Likewise, I want to be able to do this with the galaxies so I can view, for example, the distribution of galaxies in JUST the Local Group.

[alexxio]

request for better viewing from heart
http://celestiaproject.net/forum/viewtopic.php?t=9613

[ajtribick]

Not that I imagine this is a priority right now, but it would be nice to have implemented seasonal textures for planets, perhaps defined based on the planet's mean anomaly. Obvious application for Earth, although offhand I can think of Mars, Saturn and Uranus as being good candidates for this kind of thing. It would also be useful for add-ons based around eccentric extrasolar planets which might have drastic seasonal variations.

It would be useful to have this feature be able to specify cloud and specular maps as well as surface maps (adding these features to the alternate surface definitions would be good too).

EDIT: to add, presumably moons should take the time parameter from the parent planet, since this is likely to be the dominant influence in their climate as opposed to the position in their orbit around the planet.

[Hungry4info]

Request for better atmospheric graphics...

1)When viewing a planet/moon with a visible atmosphere, can we have the horizon not be so distinct? perhaps get hazy near the edges. It makes the atmosphere look really fake (no offense, of course, to the makers of Celestia).

2)We all love Titan, right? Why not have atmospheric haze? It would be more realistic than a cloud map. Perhaps the atmosphere could get more transparent as you get closer. Perhaps set it up as the transparancy being like 100% at the surface and 0% at a setable hight.

Here's kind of what I mean: (I made this up, lol)

"Titan" "Sol/Saturn"
{
Texture "titan1.*"
Color [ 0.8 0.2 0.45 ]
HazeColor [ 0.781 0.629 0.975 ]
HazeDensity 0.6
Radius 2575

Atmosphere {
Height 550
100%transparancyHeight: 5
0% transpararancyHeight: 200
Lower [ 0.477 0.367 0.211 ]
Upper [ 0.3 0.2 0.9 ]
Sky [ 0.3 0 0 ]
CloudHeight 3
CloudSpeed 65
CloudMap "titan-clouds.*"
}

CustomOrbit "titan"
EllipticalOrbit
{
Period 15.945421
SemiMajorAxis 1221850
Eccentricity 0.0292
Inclination 0.33
MeanAnomaly 120
}

Obliquity 0.6
EquatorAscendingNode 186.6
RotationOffset 318.9

Albedo 0.21
}

This, combined with the earlier atmospheric effect, and the already pre-existing atmospheric effects would be very nice indeed.

[orcus]

Hello,

I'd like to suggest a new feature added and it is that users can choose to "Follow" a certain planet (e.g. Earth) and then "make" another planet leave the trace while it moves in space and time.

I have looked up the scripting support in Celestia. There is a way to get/access objects and collect their coordinates in time, but there is no way (as far as I know) to dynamically extend the model by adding straight lines linking certain points the planet passes through in time.

For more information on a possible application of this feature, one can take a peek at my article about movement of Venus in geocentric system at:
http://alas.matf.bg.ac.yu/~mn98132/astr ... venus.html

Thanks for this great piece of software!
Miroslav