Realistic 3d nebula

[fungun]

Guys I need some help.
I am trying to make a 3d nebula which you can enter and fly through.
I am using Anim8or and a little with Wings3d.
It is for the Mutara addon I am making for Celestia (a 3d space sim)
Here is a couple pics to show what I have and what Celestia renders.
I can use 3ds files or Celestia's format called .cmod. cmod files do support illumination maps, 3ds does not. Using what in Celestia is called a dsc (deep space catalog file) it renders them transparent. While using a scc (star system catalog file) it renders it like anyother 3ds file (not transparent, but with shadows due to specular settings).
The biggest problem is making it look like clouds of gas on the inside.
Does anyone by chance have a 3ds model of a gaseous nebula?

[Fretslayer]

Do your CG apps have 'Volumetric Cloud' ability?

I use them for my nebulas and they look pretty good and you can fly through them.

Something you might want to try is to make a shape that's all scrwey (like an asteroid sort of shape) then map (with an alpha map or other other transparency) a nebula image (either real or some crezzy photoshop thing you've made) onto that object. Inside that object make several smaller versions of the same object (only spin 'em around so they're not all the same) and then texture them too. This way as you fly into the nebula you'll hit 'layers' of gas.

I hope I'm being helpful - I don't know anything about the apps you're using.

[evil_genius_180]

I knew you'd be able to chime in on this one. :) I only know how to do nebulae for backgrounds but I remember that sweet video you uploaded a few months ago with the ship flying through the nebula.

[Thomas P]

While I have used anim8or a few times (nice tool) I have no experience with attempting volumetrics with the tool. I know that it does not have that capability built into it. There is a tool called AniTweak that creates particle systems in Aim8or. It can be downloaded at http://www.biederman.net/anitweak/anitweak.zip. I'd go to the anim8or forums and ask about it first. Also, in the site gallery (#18) there is a image of a old shack out in a field - it is titled 'wheat'. The background clouds are claimed to be done in the tool. I'd try and contact the author and see how it was done.

[volkov]

I have bookmarked a couple nebula/galaxy scripts for Blender (free).

Nebula generator
http://blenderartists.org/forum/showthread.php?t=53356

Galaxy Generator
http://blenderartists.org/forum/showthread.php?t=43411

[stegoman05]

Hey cool, been trying to nebula for awhile now. Thanks for the tips.

[kageryu]

Another trick that could work is by using primitive spheres, with transparent edges and a good falloff, overlapped in clusters. Then give them a good texture set (fractal noise textures work good, if you app supports layers you can get color depth). Also apply a fractal noise type texture to a transparancy channel to help break up the shape of the sphere (if you app supports bump mapping or displacement mapping adding the there wont hurt either). Then you can deform the spheres, distort them, and move the about to give a flowing feeling to the gasses. It's not perfect, and not the best results, but with time, patience, and practice can look quite nice with far less render time or memory use than true volumetrics, or particle effects.

[evil_genius_180]

I've wondered if something like that might work. I might have to try that some day. Thanks for the cool tip. :)

[kageryu]

Keep in mind I use Lightwave alot, and am not too familiar with many other 3D programs...however, Refraction is becoming common in most 3D apps these days, so you can even give the nebula "density" by applying a refractive index to the spheres. This looks really nice when done properly in lightwave (with the air layer trick) as the multiple spheres bend the light differently. Even with the enhanced render time from refraction, it still renders slightly faster than Volumetrics. The risk here is that sometimes the refraction makes the sphere edges more noticable, depending on the camera angles.

[evil_genius_180]

My only issue with it is that I use trueSpace, which won't let you use large textures, so I'd either be stuck making small animations or a crappy looking nebula. That's mostly what stops me from doing things like this. :(