Orbits and Labels colors

The place to discuss creating, porting and modifying Celestia's source code.
ElChristou
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Post #21by ElChristou » 14.06.2007, 19:42

t00fri wrote:...And how about doing one job really well before moving to the next one ;-) ...I know, the principle of "small steps" ...


Sure, but this is a dev decision, we, non coders can just propose, you guys decide what's best... :wink:
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Cham M
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Post #22by Cham » 14.06.2007, 21:56

Here's a package of 2X three PNG pictures to compare the old (original) labels color set, to the "new" (still unfinished) color set :

http://nho.ohn.free.fr/celestia/Cham/Di ... rchive.zip (6.4 MB)

There are several constraints here, for the choice of labels colors :

1- readability on screen. This is the most important constraint.

2- the color used should not be the same for two different classes,
including galaxies labels, globular clusters labels, nebulas labels,
border lines for the constellations, celestial grids, location sites, etc.

3- for consistency, the label color should be coherent with the color used
for the associated orbit.


According to the pictures included in the pack above, my "pastel green" used for the location labels is harder to read than the "vivid grass green" used in the original color set. Should I revert to the "vivid grass green" ?

Opinion needed.
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Post #23by ElChristou » 14.06.2007, 22:00

Cham wrote:...According to the pictures included in the pack above, my "pastel green" used for the location labels is harder to read than the "vivid grass green" used in the original color set. Should I revert to the "vivid grass green" ?

Opinion needed.


The vivid green is much readable... perhaps a mix of old and new version...
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Cham M
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Post #24by Cham » 14.06.2007, 22:13

Ok, I think I've found a nice green. It's very close to the original "vivid grass green", but less agressive and more "natural". Here's a pack of pictures to compare with the previous PNG screen captures :

http://nho.ohn.free.fr/celestia/Cham/Di ... rchive.zip (3.2 MB)

Do you think this is it ?

I'll fine-tune the moons label a bit. After that, I'll channge the nebulas and globular clusters labels.
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Post #25by ANDREA » 14.06.2007, 22:17

ANDREA wrote:
Cham wrote: ---BTW, having you modified the code, is there any hope to have another change, allowing ALL orbits and labels to be visible up to a distance from Sun of, say, thrice the Pluto distance?
If you remember, Buggs and I stopped the evolution of the Ptolemaic, Tychonic and Copernican Solar System just for this reason: the labels disappear when distance from Sun changes too much, and this makes impossible to have a clear idea of these Solar Systems complexity and difference from the real one.
Any possibility?
I remember you this thread:
http://www.celestiaproject.net/forum/viewtopic ... 69&start=0
and this one:
http://www.celestiaproject.net/forum/viewtopic ... tem+labels

(Fridger, do you remember this?
toofri wrote:As I mentioned to you privately, the best would probably be to allow for an ON|OFF flag for dynamical label display in celestia.cfg
Any possibility, please?) :oops:
Thank you.
Bye

Andrea :D

Sorry to repeat my post, but it looks like none saw my previous one, or like my request be so stupid that it's not worth to reply.
But I don't think it's stupid, so... here I'm again.
Chris, Fridger, Cham, is it so difficult, time consuming or useless to add an On-Off switch in cfg file, with the possibility to choose a distance in AU at which BOTH labels AND orbit lines disappear AT THE SAME TIME, not as happens now? 8O
I remember that other people told it could be useful for many applications.
Thanks a lot, and again I beg your pardon for insisting on this request. :oops:
Bye

Andrea :D
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Post #26by Cham » 14.06.2007, 22:21

Andrea,

your request is off-topic. You should make a new one instead.
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Post #27by ElChristou » 14.06.2007, 22:25

Cham wrote:Ok, I think I've found a nice green...


Seems fine to me...
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Post #28by ANDREA » 14.06.2007, 22:28

Cham wrote:Andrea, your request is off-topic. You should make a new one instead.
Well, I'll do another one, but I supposed it was ON topic because it started as follows:
Andrea wrote:BTW, having you modified the code, is there any hope to have another change?

Anyhow, no problem, thank you all the same. :wink:
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Post #29by ElChristou » 14.06.2007, 22:32

Andrea, Cham is right, a bit off topic even if related. Now you should insist a bit for your problem, try also from the Lua side (who knows), but definitively don't give up with those historical systems!
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Post #30by Cham » 14.06.2007, 22:38

Here are the new labels for the moon (a bit less pink) :

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Post #31by ANDREA » 14.06.2007, 22:42

ElChristou wrote:Andrea, Cham is right, a bit off topic even if related. Now you should insist a bit for your problem, try also from the Lua side (who knows), but definitively don't give up with those historical systems!

Never mind Chris, I'm not used to give up if I think something be important. :wink:
IMHO the Historical Systems will have a good impact on students, so I'll make another try to search for some help.
My problem is that, not being a programmer, I have absolutely no idea on the difficulty and time needed to achieve a positive solution to this problem, so I can only ask for.
If the problem is too much complex and not worth the effort, please someone tell me this, and I'll give up.
Thanks
Bye

Andrea :D
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Post #32by tech2000 » 14.06.2007, 22:58

Cham wrote:Here are the new labels for the moon (a bit less pink)


Looking beautiful Cham, the green used in the screenshots from images in test 'c' looks great..

Keep up the good work.. Let us hope this makes it into pre4 together with faded labels.

Anders

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Post #33by t00fri » 15.06.2007, 06:52

Cham,

are these last colors from AFTER my PM suggestion to you, to make the colors less bright, such that the scene will not be dominated anymore by bright labels all over?

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Post #34by Cham » 15.06.2007, 07:00

Fridger,

we don't have much choice about the labels "intensity", or else they would be unreadable. Especially since they need to be readable for any background (black space, planet textures, yellow Io, red Mars, blue Earth, gray Moon, etc). The colors I've selected are the best compromise.

I can assure you that the green used for the locations is already better than the default "grass green", even if it's pretty close to the default color. It's less agressive, more "natural" and yet still readable on any background. Same for the other labels. ElChristou also tested my builds to confirm the choice.

EDIT : Also, the addition of some transparency effect to the asteroids and comets would help ENORMOUSLY, since some labels will be darker than others.

About the galaxies, nebulas and globular clusters labels, we already have the option (preferences) to turn ON/OFF separately all these three classes of labels. Yet, they are all using the same label color (see my PM). This is inconsistent. They need to have their own label color, not the same for all three classes. Some code lines should be added to the 'render.cpp' file to tell Celestia to draw three different labels famillies : galaxies (already present), nebulas and globular clusters, as already defined in the preferences panel.
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Post #35by t00fri » 16.06.2007, 14:48

Cham,

I now have transferred your above given color assignments for orbits & labels to the code to try the color out both on my analog monitor and my tft laptop.

I must say that the pigeon blue color for planet names is partly badly visible (e.g. in front of Jupiter's cloud belts) and the bright pink color for the moon labels tends to make me nervous after a while ;-)

You probably further optimized the colors, but that was all I had available.

Bye Fridger
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Post #36by Cham » 16.06.2007, 17:54

Fridger,

the colors I'm using are these :

Code: Select all

Orbits :
      Planet: 0.0, 0.4, 1.0

      Moon: 0.43, 0.0, 0.55

      Asteroid: 0.35, 0.2, 0.0
           
      Comet: 0.45, 0.44, 0.11
         
      Spacecraft: 0.4, 0.4, 0.4
           
      Stellar: 0.5, 0.5, 0.8


Labels :
      Planet: 0.15, 0.74, 1.0
       
      Moon: 0.85, 0.45, 0.91
 
      Asteroid: 0.84, 0.62, 0.28

      Comet: 0.87, 1.0, 0.43

      Spacecraft: 0.73, 0.78, 0.90


LocationLabel : (line 4787)

      0.22, 0.94, 0.44


I think the "pink" moon labels are very beautifull with their orbits. In the case of the planet labels, I can't make them better, or else they'll come too close to the stars labels, or the galaxies labels.
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Post #37by t00fri » 16.06.2007, 19:57

Cham,

just getting back from a nice dinner...

I took a little while and coded the three different labelcolors for Galaxies, nebulae and OpenClusters.

I post the code shortly, when I have tested it a bit further.

One of the issues to take into account is that due to the largely different distance scales one has to incorporate the label fading differently for the three DSO varieties.


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Post #38by Cham » 16.06.2007, 20:08

t00fri wrote:One of the issues to take into account is that due to the largely different distance scales one has to incorporate the label fading differently for the three DSO varieties.


Agreed. Try also the colors as defined in my previous reply.

I intend to give a red shade to the nebula labels, and a green variation to the globular cluster :

Code: Select all

Nebulas labels :

      1.0, 0.25, 0.25


Red isn't much used (except, of course, for the selected path), and green as been used only for the location labels. After that, I think we'll have used ALL colors we could define for Celestia (without "overlapping"), while satisfying the readability criteria.
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Post #39by t00fri » 16.06.2007, 20:25

Cham wrote:
t00fri wrote:One of the issues to take into account is that due to the largely different distance scales one has to incorporate the label fading differently for the three DSO varieties.

Agreed. Try also the colors as defined in my previous reply.

I intend to give a red shade to the nebula labels, and a green variation to the globular cluster :

Code: Select all

Nebulas labels :

      1.0, 0.25, 0.25


Red isn't much used (except, of course, for the selected path), and green as been used only for the location labels. After that, I think we'll have used ALL colors we could define for Celestia (without "overlapping"), while satisfying the readability criteria.


Funny, I have already assigned a rosty red color to the Nebula labels ;-)

Bye Fridger
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Post #40by t00fri » 16.06.2007, 21:36

OK, Cham & other label-affectionados,

I finsihed the code in render.cpp that now allows to separately assign label colors for the 3 DSO classes: galaxies, nebulae and openclusters. I added some automatic label fading also for nebulae and openclusters PROVIDED you add an AbsMag entry into Nebula and Cluster .dsc files.
The fading will definitely have to be finetuned with more examples!

I also used Cham's latest color assignments throughout.
The nebula labels are red (see below) and the cluster labels a variety of green.

The label fading for nebulae was tested for an Orion nebula addon that has the following .dsc entries

Code: Select all

Nebula "M42"
{
    Mesh "M42-43.3ds"
    Radius 12
    RA 5.5833
    Dec -5.4951
    Distance 1177.748
    AbsMag        -4.1
}

Nebula "M43"
{
    RA 5.592
    Dec -5.31
    Distance 1177.748
    AbsMag        -3.0
}

Nebula "NGC 1977"
{
    Mesh "NGC1977.3ds"
    Radius 7
    RA 5.590
    #Dec -4.795
    Dec -4.785
    Distance 1177.748
    AbsMag        -2.1
}


Note the AbsMag entries!

Here is how things look like with Cham's proposed colors:

Image

Not bad and the labels vanish smoothly at larger distances...

Here is my modified render.cpp in zipped form. Unzip it, replace the original (latest) CVS file and recompile.

http://www.celestiaproject.net/~t00fri/images/render.cpp.zip

Let me know your feedback.

Bye Fridger
Last edited by t00fri on 16.06.2007, 21:45, edited 1 time in total.
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