Shadow within a comet coma


Hi William,

Even though they are largely composed of water ice, comet nuclei aren’t translucent in any of the NASA or ESA images I’ve seen. However, only a handful of comet nuclei have ever been imaged at close range so who knows?

The brighter reddish patches on the “darkside” of my object are meant to be “active” regions on the surface. Today I added a gas jet that erupts from one of those red areas. In reality, the night-side of a real cometary nucleus would probably be as black as coal, but I have to “hollywood-ize” my stuff to keep it lively (thereby keeping my clients happy).

You are right about Smokers; they are very useful. There are eleven in my project so far, and I expect that number to increase.

See you later,

Joe T


Hi All,

Here’s the update you requested (Ian). I don’t have the bandwidth for a nice video, so here’s a clunky animated GIF showing every 50th frame of my outgassing comet coma (minus the starfield). There are 18 gas jets (glow lights) each with its own uniquely configured Smoker. A Maya-using friend has already asked for an HDTV rendering of this for possible use in a show.

This wouldn’t have been so dramatic without the shadow technique William gave me - thanks again for that!

p.s. I am replacing the animated GIF with a 15fps QT movie.




very nice, but I would like to see a more FPS version…

for the bandwidth problem, you can upload to youtube or some other web brodcast if you don’t mind…

thanks for sharing


Beautiful, i can understand the interest of your friend for an HDTV rendering. I think must be very interesting to see it in large size. I can´t imagine how you get those gas jets with the smokers, they really looks as particles with all the subtile details and twists of the gas. Great work.



Hi Loon and Felix,

Thank you for your nice comments on my project. Loon, I’ll try to get a video up somewhere for you. I’m not sure I want to register with YouTube; it looks too crazy there for me. A few years ago, I registered with another edgy site and I cannot get off their mailing list.

Felix, in order to achieve all the different textures in the gas jets, I just used various settings on the glow lights and Smokers. If anyone would like to see them I could email a copy of my project. I’d have to substitute an uber-sphere for my asteroid, though. My asteroid is about 13 Megabytes in size and I still use an old-fashioned, dial-up internet connection!

Joe T


Hi, Joe. Very kind of you for offering your project for study. I could be very happy if you can (when you have some time) send me a copy of the project. BTW would be a good idea to have some kind of projects repository in the Ei web site…


Lets make our own… After all, the new EI site has a WIKI :slight_smile:

Great work Joe, I really hope you find a way to get a full speed version online :wink:

Again, damn fine stuff,


Hi Felix,

My project contains almost two dozen lights and has a file size of about 2.8 megabytes. If you’ll send me your email address (contact me at I’d be happy to send you the project. I’ll have to substitute an EIAS rock or an uber-sphere for the nucleus I used; my ZBrush nucleus is about 12 megabytes (it has a lot of craters) and I can’t put that through my email service.

Hey Ian,

Thanks again for your damn fine comment on my project!

Best Regards,



Hi Loon,

I put a compressed, 15 fps QuickTime clip of my outgassing comet nucleus in place of the animated GIF. Please follow the link in my earlier message and it should load up for you (I hope).

Joe T

tumbling nucleus


What more can I say, it’s every bit as good as I expected it to be! :smiley:

Congrats, I really hope it ends up in your friends show!


Veeeery nice done, Joe. All the little details sells perfectly the shoot.
Great work.



Hi Ian,

Thank you very much for your nice comment. I couldn’t have done it without all the tips you and other contributors to these forums have made.


Joe T


Hi All,

I thought I’d update you on my comet project, especially since you guys (William and Richard) helped me along the way.

After I finished setting up the project I rendered it at 1920x1080, 60 frames per second. That way I could be ready for just about anything. It’s a good thing I had it “on the shelf”; I received a request for the footage on very short notice. It’s being worked into a History Channel show about comets.

Thanks again!

Joe Tucciarone


Thank you for the feedback Joe. This is great news, I’m gonna watch for that show…!
This is a large render, would you care to post render time and hardware if you noted it?


Hi Richard,

I’m on vacation right now and miles from my studio but here’s what I remember:

The project contained 18 lights of which about 13 were glow lights shining through Smokers. The nucleus was a ZBrush asteroid; in FACT file format I think it was 45 Megabytes although I forget how many polygons it had. The debris consisted of about 35 Ubershape rocks set to detail level 2. The ZBrush nucleus and every rock were set to cast shadows. I used “Raytrace” Camera but since the motion of the debris was so slow I didn’t use any motion blur and it looks fine.

I still use EIAS version 6.5.2. I was in no hurry at the time so I didn’t kick on my renderfarm; I rendered the 25 second project on a dual Mac G5 (1.8 Gig). With both processors rendering it took 3 and a half days to make the 1920x1080, 60 fps animation.

Joe Tucciarone


Thank you, have a nice vacation.


This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.