Celestia Forums

I have had a go at modelling some nebulae in 3D.I guess they look a little bit like Christmas tree ornaments at times but you can also get some nice views from inside.

According to Grant in this thread
http://www.shatters.net/forum/viewtopic.php?t=5920&start=15
you would not see much up close to one of these (which is a pity)

There is a 3ds version here
http://celestiamotherlode.net/creators/jestr/ScorpioNebulae_3DS.zip
and a CMOD version here
http://celestiamotherlode.net/creators/jestr/ScorpioNebulae_CMOD.zip
Let me know if there are any innacuracies in the Dsc file,all the best Jestr

Good stuff! Thanks!

These look great jestr...I will definatley give these a go! ...just got Rassilons NGC1999 and Rosetta working on my setup at last! These are benchmarks methinks.

Regards...bh.

bh wrote:These look great jestr...I will definatley give these a go! ...just got Rassilons NGC1999 and Rosetta working on my setup at last! These are benchmarks methinks.

Regards...bh.

Just? Its been working for me ok...glad its working now though...

Very nice work jestr...

jestr wrote:I have had a go at modelling some nebulae in 3D.I guess they look a little bit like Christmas tree ornaments at times but you can also get some nice views from inside.

Looks very very great (your screenshots), but...
Please, Jestr, can you provide this add-on with another texture format than .dds? Please, please please
Jeam

These nebulae look great, although they make my system slow...
just a question of patience, really.

a really small nebula like that would work well as an artificial solar collection swarm; I might try something along those lines.

how do you extract the accurate location of a star so as to centre a nebula on it?

Hi Jeam,I have made a PNG version will let you know when I have a link for it.It is a little duller though as I made the PNG's from the DDS versions.
Eburacum,trial and error really,I find the coordinates for the star,butI think these reference a different ecliptic than the DSc files so I usually have to adjust it by trial and error until it looks right.Maybe someone else knows a formula for converting the two sets of coordinates?Jestr

Jeam,

There are several programs that can convert DDS into JPEG or PNG. i use Infranview.

eburacum,

The J2000 RA and Dec of stars and nebulae can be found by searching the SIMBAD database at http://simbad.u-strasbg.fr/sim-fid.pll. The Hipparcos star database, which includes distances, can be searched at http://astro.estec.esa.nl/Hipparcos/HIPcatalogueSearch.html.

I usually just do a Web search, though. The "spectrographic distance" is avaiable for many stars. It's an estimate determined from spectral type and brightness.

As Jestr mentions, though, you usually have to use trial-and-error to center a model properly. The official location of a nebula usually is nowhere near the center of its picture. There's a discussion of this problem at http://www.lns.cornell.edu/~seb/celestia/billboard.html#6.0

Thanks Jestr. I'm waiting for this stuff

selden wrote:Jeam,
There are several programs that can convert DDS into JPEG or PNG. i use Infranview.

Yes, Selden, i converted them with PSP, but curiously, cant edit links to png textures in the .3ds files (with Anim8tor). I can add jpg links, but it is not so good that Jestr screenshots.. This is for 3ds pack, i don't try yet with CMOD, because i don't know how to edit this format (i.e. pointed png textures instead of DDS ones)Jeam

I made a dyson swarm nebula, and tried to fit it round Delta Capriconi (the Orion's Arm colony Ain Soph Aur);
the closest I have managed to get it is 5 AU so far...
also it seems to disappear when I make it smaller than 1 AU in radius; is this normal?

I have made it into an object in orbit around the star, but it turns opaque when I do that (I wonder why)...

eburacum,

Celestia makes some simplifying assumptions about the distances at which Nebula models can be drawn. There also are bugs in some of Celestia's clipping algorithms. Either could be affecting your swarm.

Celestia draws surface texture images differently depending on where they're specified. In particular, when a surface texture is specified by using a Texture declaration in an SSC file, it's drawn opaque and its Alpha channel is used to define its specularity. If a model specifies the name of a surface texture image internally, the image's Alpha channel is used to define its opacity.

Also, more direct control is available over some of the ways a material is applied to a model if you convert a 3DS model to ASCII CMOD format. You can edit the CMOD model file to change the names of the surface texture images, as well as the opacity, specularity, etc.

The CMOD conversion utilities are available in http://www.shatters.net/celestia/files/cmodtools-win32-1.0.0.zip

They'll have to be rebuilt from their sourcecode on SourceForge for other platforms. It'd be nice if the Mac port of v1.3.2 (being worked on now) were to include them in its distribution.

I like very much the nebula,because you can "enter" in it.There is some kind of depth.
I would like to ask what?s the difference between saving in another format(for example,from bitmap to jpeg) and converting to another format?Is there any loss?I wonder if I simply take a jpg image and save in png,if I will see a transparent image(a image with alpha channel).
Do the Adobe can do the conversion?

eburacum wrote:I made a dyson swarm nebula,

That's another superscience thing I've never heard of before you mentioned it - what's a "dyson swarm nebula"?!

Evil Dr Ganymede wrote:That's another superscience thing I've never heard of before you mentioned it - what's a "dyson swarm nebula"?!

Hey, planet-builder, when are you going to realize that planets are just so yesterday?
It's a solution to the problem of Dyson's "total star enclosure" that doesn't involve that pesky massive sphere with no gravity inside ... just a dense habitat swarm that intercepts a large proportion of the star's radiation. It presumably would need fairly constant station-keeping to maintain all those orbits without the whole lot decaying gravitationally into a ring.

Grant

Oh, right. Why didn't he just say that then...!

I have now added a third version of the nebulae addon with PNG textures.It is a little more transparent than the DDS versions-it has 3ds format models.Here is the link
http://celestiamotherlode.net/creators/jestr/ScorpioNebulae_PNG.zip
Cheers Jestr

Thank you for the link, Selden.

Evil Doctor; apparently a donut shaped swarm is quite stable, although the one I am making is just a spherical swarm, actively maintained.

jestr wrote:I have now added a third version of the nebulae addon with PNG textures.

Many thanks, Jestr, it runs slowly on my poor computer, but looks superb. To add soon screenshots and links in my catalog. Cheers

Jestr your neublae are so nebulous. They actually feel tenuous and well not just like a flat thing. It feels volumous. Great work. Were can i find other nebulae on par with yours?