View Full Version : Volumetric Jet Engines

Richard Hebert
06-11-2014, 08:00 PM
Hi Guys!

I'm using a single volumetric hypervoxel for creating the gaseous combustion effect for a jet engine. What I would like to do is have the hypervoxel's size change with regards to the opening and closing of the exhaust nozzles by tying the two parameters together. This is a new area for me and I've tried using a Set Driven Key to attach the parameters but this is over my head. Has any of you had to do this on a project and what would you recommend? Thanks for any insight.


06-12-2014, 07:30 AM
I'm sure there are dozens of ways, but since I was just playing with this last night.....

In the envelope for the particle size try using the Modifier "Channel Follower". Reference one of the scale channels from the nozzle and the particles should follow along.

You could also try Cycler.

edit: maybe I should have asked how you have the nozzles opening and closing first.


Richard Hebert
06-12-2014, 05:03 PM
Sorry, I should have mentioned the nozzles better. All of the nozzle elements rotate at their base to open and close. It's this rotation of the elements that determine the size of the opening and ultimately the size of the hypervoxel at least that's the goal.

06-13-2014, 08:26 AM
Right, okay, soooo.... I'm gonna stick with my first answer. :)
Add a Follower that references the Pitch of that nozzle controller.
Whenever you open the nozzle the voxel(s) should get bigger.

Sweet plane!!

06-13-2014, 09:58 AM
How are the nozzles rigged?

Vaguely in my mind is it might be good to have TWO multiplicative controls for the hypervoxels: suppose you want to have the engines sputter or flame out? The nozzles would remain open, but the flare would go out.

So, if either NOZZLEWIDTH or FUEL=zero, the product (NOZZLEWIDTH x FUEL) would be zero, and the hypervoxel would 'go out'.

IOW, Expressions. BUT, pretty darn simple Expressions.

Richard Hebert
06-13-2014, 04:49 PM
Expressions are a little bit tricky for me right now but will definitely look into that avenue as things progress. Eating an elephant one bite at a time. For the record the model was a free download... sigh... I wish I could model something like that. Maybe when I'm done with this elephant I'll eat another! Thanks for the tips, I'll post the end results with full turntable renders. I'm really liking this project.