Sprites Nebulae for M31 (Andromeda's galaxy)

[Cham]

I'm releasing 8 sprites models for the Andromeda galaxy (M31).

WARNING ! In Celestia 1.6.1, you'll get a luminous colorized pixel on your screen when you're standing very far away from the models (inside the Milky Way, for example) : unfortunately the sprites models do not fade away with distance.

To get rid of these colorized pixels rendering at a large distance, turn OFF galaxy rendering (I know, this is just an annoying and partial solution).

This bug has been fixed in Celestia 1.7.0 special edition for OS X (see this thread : viewtopic.php?f=4&t=17423)

For 1.6.1, there's a (partial) solution : Use a celx script to render all the models invisible, without turning OFF the galaxy rendering. I'll give a small script example in another message below.

8 DSC nebulae models in M31, called M31 (centre), M31A, M31B, M31C, ..., M31G (stars distributions are included in the addon for each nebula) :

M31Nebulae.zip

(11.16 MiB) Downloaded 566 times

(11.7 MB zip file)

Some previews of these models :

[Cham]

Here's a small CELX script to turn ON/OFF the M31A sprites nebula published above. You can do the same for any other DSC model :

Code: Select all

-- Title: Turn ON/OFF the M31A sprites nebula

M31A = celestia:find("M31A")

   if not M31A:visible() then
      M31A:setvisible(true)
      celestia:print(" The M31A sprites nebula is now visible.", 8)

   elseif M31A:visible() then
      M31A:setvisible(false)
      celestia:print(" The M31A sprites nebula is now invisible", 3)
   end


M31A.celx.zip

(693 Bytes) Downloaded 312 times

The script could be extended to turn ON/OFF all your sprites nebulae at once, using just one script instead of several scripts, if you wish.
That way, you could get around the rendering bug of Celestia 1.6.1 :

Code: Select all

-- Title: Turn ON/OFF 8 nebulae in M31

   M31Center = celestia:find("M31 (centre)");
   M31A = celestia:find("M31A");
   M31B = celestia:find("M31B");
   M31C = celestia:find("M31C");
   M31D = celestia:find("M31D");
   M31E = celestia:find("M31E");
   M31F = celestia:find("M31F");
   M31G = celestia:find("M31G");

   if not M31Center:visible() then
      M31Center:setvisible(true)
      M31A:setvisible(true)
      M31B:setvisible(true)
      M31C:setvisible(true)
      M31D:setvisible(true)
      M31E:setvisible(true)
      M31F:setvisible(true)
      M31G:setvisible(true)
      celestia:print(" 8 sprites nebulae in M31 are now visible.", 8)

   elseif M31Center:visible() then
      M31Center:setvisible(false)
      M31A:setvisible(false)
      M31B:setvisible(false)
      M31C:setvisible(false)
      M31D:setvisible(false)
      M31E:setvisible(false)
      M31F:setvisible(false)
      M31G:setvisible(false)
      celestia:print(" 8 sprites nebulae in M31 are now invisible", 3)
   end


fakeM31Nebulae.celx.zip

(829 Bytes) Downloaded 326 times

Take note that you could make all the nebulae invisible by default by adding the line "Visible false" in their DSC definition. For example :

Code: Select all

Nebula "M31A"
{
   Visible false
   Mesh "Nebula17.cmod"
   Radius 60
   RA 0.7068265033
   Dec 41.56914334
   Distance 2529060.270
}


Added after 15 minutes 20 seconds:
If these models, their scripts and the stellar distributions are all working great on your system, I may release other addons like these for M33, M81, NGC 300, NGC 404, LMC, and the Milky Way.

[FarGetaNik]

Thanks for sharing They look great! Are these real nebulae or just random ones? I'd love to see some nebulae in the milky way represented that way
Unfortunately I use Windows and can't install Celestia 1.7, but I don't find that pixel bug that annoying, more the fact that they need much time to load even when only one pixel is didplayed. I'll try your scripts

[Cham]

The models are all random. There's no way I could make some real nebulae for the Milky Way, since they are very complex, and we don't have enough information about their real 3D shape.

I made two or three nebulae for the Milky Way, located in the "unknown sector" (on the other side of the central galactic bulge). I don't want to interfere with real known nebulae in Celestia, since that would be misleading.

If you have a SSD "hard drive", the models should be very fast to load. Even on my old 5200 RPM HD, they load fast enough.

[FarGetaNik]

Cham, ok I guessed so. Still pretty nebulae

If you have a SSD "hard drive", the models should be very fast to load. Even on my old 5200 RPM HD, they load fast enough.

Well SSD are pretty expensive right? I'm using a 3-year-old laptop with an ordinary HDD. Ok they take around a second to load, that's not too bad. For similar reason, I usually run Celestia on medium texture resolution, since it takes forever to load the cluster of textures in the Earth-Moon, jovian and saturnian systems. I also limited the texture size to 8k and use virtual textures if necessary.

[Cham]

Prices of SSD are much more reasonable now. I'm thinking about changing the HD of my old computer (6.5 years !) to a SSD, maybe soon.

Added after 2 minutes 34 seconds:
FarGetaNik,

post some pictures of the nebulae on your system. I'm curious to see how they are rendered.

[FarGetaNik]

Hm I might look that up, I was thinking of getting a tower computer. It would really be a relief to run all Celestia content on a SSD

[Goofy]

Hi.
When I susbstituted my 750 GB HD (7200 rpm) with a 250 GB SSD, I saw a new world.
Expecially with very heavy addons (e.g. Linuxman's ISS) the loading speed now is a bullet shot!
In Italy a quality 250 GB SSD can be found at 80 Euros, same price of a 2TB 7200 rpm HD, but despite the 8 fold price/capacity difference there is absolutely no possible paragon, SSD wins!
Try and enjoy it.
BTW, I'm neither an SSD producer (alas!) nor a seller!
My 2 cents.
Goofy

[FarGetaNik]

post some pictures of the nebulae on your system. I'm curious to see how they are rendered.

Ok here we go.
From home it looks like this:

Loading them all at once actually takes several seconds, I checked.

Here a closeup of one of them, with 2 other in the background:

Looks really pretty

Added after 4 minutes 18 seconds:

When I susbstituted my 750 GB HD (7200 rpm) with a 250 GB SSD, I saw a new world.
Expecially with very heavy addons (e.g. Linuxman's ISS) the loading speed now is a bullet shot!

Don't make me jealous, I want to keep my Laptop for a while or I might just get an extra SSD, if I remember correctly I have 2 disk slots