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PostPosted: Fri, 17-02-12, 17:27 GMT 
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Hi all,

after discovering yesterday in the Chang'e 2 texture certain regions of misalignment w.r.to the 32k LRO-LOLA normalmap VT, I became a bit demotivated to continue working with the Chang'e 2 texture.

viewtopic.php?t=424&start=6

Nevertheless, my Chang'e 2 project has some features that are rarely found among existing large size Moon textures: Color. Also, the misalignment turns out to be a rather local effect, and there are large regions looking just beautiful.

Therefore, I think my final Chang'e 2 texture may well deserve a little "photoshooting" after a considerable amount of work ;-) .

Clearly, a computer and template based implementation of color becomes forbiddingly slow or even impossible for "multi-GB monster" textures and "normal" computers. Even with my 32k texture, any change typically may take hours (!) in GIMP.

Hence, I would be most grateful about your opinion concerning a scientific level implementation of color in such texture renderings! Since it amounts to a significant extra effort, other opinions are certainly important for me.

I must confess that I am sick of this abundance of mere grayscale renderings of celestial bodies in Celestia, despite the available huge texture sizes. The color degree of freedom is a most important visualization aspect, and quite often smaller texture sizes with subtle colororation outweigh gray "monster" textures as to details, transparency and esthetics! In Celestia.Sci color is anyway a central aspect...

The following screenshots were all done with only a 16k colored Chang'e 2 texture. The color template was the best existing 5 band colored UVVIS Celementine Moon imaging from here.

http://ser.sese.asu.edu/MOON/clem_color.html

Since 16k can still be handled rather quickly in Gimp, the texture implements also a round of careful wavelet denoising and a proper adjustment of brightness and contrast. Unlike John VV's rather pale Mare regions, the Mares in my texture are darker in color, more like in unaided vision. There is one technical reason, why the Mares look pale and the illuminated regions are shiny in John's nice textures:

He has added in the .ssc file of his 64k LRO-WAC add-on
a rather big amount of specular lighting,

SpecularColor [ 0.24 0.23 0.21 ]
SpecularPower 2.5

without adding a specular black&white mask that would make the mares unreflective and thus appearing with their original, dark color. While there is no physical reason for such a "shinyness" of our Moon, it undoubtedly has an enhancing effect.

After these thoughts of mine, have a look at the Chang'e 2 "photoshooting":

[use Browser Fullscreen (F11 for FF) by all means!]
Image

Image

Image

Zooming-in now. Note the subtle tones of color...
Image

Image

Image

Image


Enjoy,
Fridger


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PostPosted: Fri, 17-02-12, 19:35 GMT 
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Very nice... :o

I wish I had the time to dig again these tools of yours because my Celestia config is now quite dusty in comparison... :?


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PostPosted: Fri, 17-02-12, 19:44 GMT 
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ElChristou wrote:
Very nice... :o

I wish I had the time to dig again these tools of yours because my Celestia config is now quite dusty in comparison... :?


Hi Christophe,

thanks for the "flowers". I am always a bit sad when I read your rare mails. I then remember that we had a good time a while ago with Celestia, CM and all that... I sincerely hope that you are fine!?

Cheers,
Fridger


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PostPosted: Fri, 17-02-12, 21:41 GMT 
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Looking good! :D I noticed in your post you said that these misalignments were localized. Not thought the entire image? Did you ever try qnet? This is what I used to use to correct alignment problems with MRO CTX images.

cartrite


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PostPosted: Fri, 17-02-12, 22:21 GMT 
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cartrite wrote:
Looking good! :D I noticed in your post you said that these misalignments were localized. Not thought the entire image? Did you ever try qnet? This is what I used to use to correct alignment problems with MRO CTX images.

cartrite


NO, I never did! Is it easy to describe how it works in case of local misalignments? Note here the alignment issue concerns a surface map and a normal map.

Thanks
Fridger


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PostPosted: Fri, 17-02-12, 23:46 GMT 
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Unfortunately, this will probably be a tough job. I only did surface maps. Slight alignments were needed because of different angles of the sun, spacecraft position, etc. when the data was acquired This was when I was working on Mars images.

I would guess that a really high contrast normal map/ topo map would be needed to find a point common to both datasets. and then qnet interpolates the pixels if you get a successful match. but even with only surface maps, it is very time consuming and tedious.

All the alignment problems may still be due to 2 different ways the maps were created. Maybe we should get someone who speaks Chinese to translate what was actually done. :?
cartrite


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PostPosted: Sat, 18-02-12, 8:03 GMT 
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t00fri wrote:
...I am always a bit sad when I read your rare mails. I then remember that we had a good time a while ago with Celestia, CM and all that... I sincerely hope that you are fine!?


I'm fine, do not worry!
Now I must confess still after this time my Celestia venture left me a bitter taste... What a barbary what happens to this nice project... I definitively don't understand how people works in this crazy word!

Anyway the day the engine of your Sci project will be ok and if you need help with gui matters I'll be happy to give a hand! (at design level of course!)

And definitively I do always have an eyes over CM so... :wink:


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PostPosted: Sat, 18-02-12, 11:28 GMT 
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ElChristou wrote:
t00fri wrote:
...I am always a bit sad when I read your rare mails. I then remember that we had a good time a while ago with Celestia, CM and all that... I sincerely hope that you are fine!?


I'm fine, do not worry!

Great!
Quote:
Now I must confess still after this time my Celestia venture left me a bitter taste... What a barbary what happens to this nice project... I definitively don't understand how people works in this crazy word!


Well, Celestia development is effectively orphaned meanwhile. ChrisL ( aka Periapsis Visual Software) is commercially offering a featured, best-selling MAC app of a "relative" of Celestia called Cosmographia, of which he has the sole Copyright.

http://itunes.apple.com/us/app/cosmogra ... 7543?mt=12
http://www.cosmographia.info/
http://code.google.com/p/cosmographia/

Note that the code may be also downloaded and built free of charge.

During the past year, Chris has been working hard on the code that certainly has some structural advantages compared to "aging" Celestia. The range of Cosmographia is however limited to the solar system.

In the meantime, I am working hard and steadily on Celestia.Sci. Despite lots of nice progress, it is plenty of work for one guy who doesn't want to spend the rest of his life exclusively in front of a computer ;-) . After lots of practice, I am also feeling very comfortable with coding OpenGL.

Quote:
Anyway the day the engine of your Sci project will be ok and if you need help with gui matters I'll be happy to give a hand! (at design level of course!)

And definitively I do always have an eyes over CM so... :wink:


Thanks!!

Fridger


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