CompuServe Thread

#Great Gas

6 messages in this thread
#88981From: Stephen GaleAug 29, 1994 3:32 PM
Has anyone figured out how to make the excellent streaks of "space gas" as seen in Babylon 5? I've been experimenting with various textures and fog object effects but so far the effect has been comparitively feeble. Nebulas are fairly easy, but those streaks…ugh! Any sugestion would be appreciated.
#89070From: jeff HolinskiAug 31, 1994 12:32 AM
If you've got Forge and Essence2 there's an easy way to make a nebula. Start with the cyclone texture and render out a grayscale image of it. This will be a transparency map. You should make sure that the cyclone size is smaller than the window so it will have a completly black background all the way around it. I use no twist for the cyclone. This gives a nice blotchy cloud. You then make it a negative with Adpro or similar program. This will make the outer parts of the image fully transparent and the cloud in the center semi-transparent. I suppose you could also render the image with a white background and make the cloud color black so you didn't have to make the image a negative. Once you have the image you map it onto a square, flat plane as a filter map. Add some fractal color. (medium red and dark blue seem to look good) Now stretch the plane in one direction. (at least 2X on the 'X' axis) This will stretch the image and give you a more streakish nebula. I've used this system with LightWave and found that it gives better results than most of the fog-object Imagine nebulas I've seen. Note: There was a bug in Imagine 2 that wouldn't render starfields through transparent objects although It may have been fixed in Imagine 3. I think I might have uploaded the LightWave nebula object into the Amigaarts/3D library. While the object isn't usable with Imagine the image is a good starting point. (the object is just a flat plane)
#89100From: Stephen GaleAug 31, 1994 11:51 AM
Thanks Jeff, Actually I've done something very similar, except I used Impulses NEBULA texture. With this I've made pretty convincing exploded looking clouds. Its really a different look though from Babylon 5's gas clouds. They are long and have the look of streams of gas being "pulled" (if that makes any sense). The only thing about B5 is every space scene has one of these, and cool as they may be it's hard to imagine so much gas could exsist in space! I've been toying with ghost objects and combineing these with texture mapping but so far nothing. Thanks for your input — SGinNJ
#89135From: Jim ShieldsAug 31, 1994 7:54 PM
We do gas streaks by drawing them in a paint program (Fractal Painter on the PC, usually) and then using the resulting image as a color and/or transparency map.
#89136From: jeff HolinskiAug 31, 1994 8:42 PM
One point of view is that there seems to be a lot of nebulas in Babylon 5. When you consider that nebulas can be hundereds of light years across you'd think that you'd see a cloud whichever direction you were looking if you were in an area with a lot of dust. I always thought that the nebulas in Bab5 were too small and dense to look real. (perhaps the dust is ionized by ships passing through the area at high sublight speeds and it pulls together.) ;^)
#89268From: Stephen GaleSep 2, 1994 8:33 AM
Dont get me wrong Jeff, I think they look great (hense the subject name!). But of all the TV sci-fis I've seen, B5 is the only one with nebulas everywhere. Star Trek for example has very few, DS9 almost none. I guess B5 has lots cause they can, its probably a pain making that effect in the real world but in 3D they're just another object. Last night I tried streching my nebula plane along the X axis to expand it and it worked fairly well, although compared to B5 its not impressive. Anyway, it seems transparency maps are the popular answer, guess I better bone up on my outer space illustration techniques. SGinNJ