Jet Exhaust in VRay with Particle Emitter

#1

Hi,

I am trying to create some type of jet exhaust / fire effect. Something like this, for example: http://www.shutterstock.com/video/clip-2905804-stock-footage-jet-engine-test-fired.html

So I’ve been looking around online on other threads, tutorials and whatnot. The common suggestion seems to be to use Maya’s Particle Emitter. I have been testing it out, following tutorials and such, and it seems to be working decently with Maya’s default render engine. But when I switch to VRay and render, the particles don’t seem to be rendering?

It says that most of the render types are not supported and it is using spheres instead, so I switched the Particle Render Type to Spheres and it works, so… are only spheres usable?

And are there any other suggestions on how I could better achieve this effect?

#2

I guess it depends on the look you’re going for. In the footage you linked The flame is very smooth, personally i would suggest a fluid for this. I guess it would be do able with particles too, but they would need a lot of smoothing out.
I cant comment on Vray specifically but rendering as spheres will make the particles rounded, for flames like this you need a flat look. You could possibly crank up the motion blur and render as a seperate pass to make the particles merge more. Looking at the footage again rendering some soft curves could also add to the effect.

#3

Thanks for the suggestion, yeah I’ll try using fluids too.

Emitter seems to be giving more of that puffy, cloud look (even with adjusting, at least from what I’ve been able to do) instead of that straight, smooth edge I need.

#4

The particles motion is cloud like, or the render is cloud like? Feel free to post a scene file, i can try to look at it. (needs to be .ma)

#5

The particles themselves are cloud or puffy like.
For example, this tutorial was the basis and starting point I used first: http://s979.photobucket.com/user/daverave-2010/media/MayaProjects/JetExaust2.mp4.html

Though of course that effect/look is different than what I was going for, as that’s like fumes and clouds that emit from the motion of the object.

Here’s another example I found: http://www.shutterstock.com/video/clip-5892332-stock-footage-turbojet-engine-aerodynamics-thrust-test-black-jet.html?src=rel/2905804:2/3p

I guess I’m going for a combination of this one and the first one I linked in the original post. Where it’s much more a straight-edged and clear outline/shape for the flames. The colors and transparency can be a bit faint and soft, but its shape is sharp and short, like its bursting out.

I tried using a Directional emitter so it is shooting out towards the direction I want, and it’s getting better. Here’s a picture of what I mean:

Here’s my scene file for it: https://www.mediafire.com/?r4ta959t4kz951f

As for fluids, I’ll give that a shot soon, though I am doing some tutorials on Maya fluids currently ha so I can get the basics first.

#6

Ok so i had a quick look at your scene. First off i would recommend using nParticles over classic particles as you can have far more control over their behaviour, and interaction with other nucleus objects.

As for the look, i didnt know the length you were going for, but this can be easily changed with the lifespan.

Also the speed may need to go up, but be sure to change lifespan accordingly.
To get the exact shape, size and falloff you want mess around with the opacity and radius ramps.

To get that sharp edge you were looking for, ive turned spread off, turned rate up, altered the npCloudVolume to be more dense and the opacity ramp. As such the edge is very sharp now, and the render non-transparent until the end of the tail, so you may want to alter the overall opacity or the ramp and rate accordingly.

I couldnt save as a .ma so its will be better to just drag and drop than open the file directly incase of errors. Just rendering with Mental Ray for now.
Thruster.zip

To build on this you could add a second particle system for smaller bits, or to get the thin smooth lines you see inside the flame on your first example.
Let me know if you need anymore help or if anythings unclear :slight_smile:

#7

Wow, thanks a lot!

The effect is good, very close to what I’m wanting. I’ve never used nParticles so I’ll have to play around with it a bit and tweak stuff around just to get the hang of the settings. I’ll post again if I run into questions and whatnot.

Thanks again in the meantime though!

#8

Bumping this post since now I’ve finally had the time to test out the thruster effect.

It’s working nicely but I’ve run into another issue now. The thruster itself, its form and effect is good. But if I start moving the nParticles (since whatever object is releasing the exhaust would be moving/flying), they start emitting in the direction of the object’s movement, going in front of the object.

So how can I adjust it so that it continues to emit downward, or at least in the opposite direction of its trajectory so it would actually look like an object is emitting and moving forward with the fumes.

I’ve attached my scene where it’s just the emitter and I keyframed it to move sideways.

EDIT: Ah, okay. So I was grouping all the emitters/particles together and moving them. So now I’ve just keyed the Emitter itself and it seems to be working better, in terms of it still shooting downward and not changing its rotation. Unfortunately it loses its like sharp, triangular shape when it moves fast so I’ll have to play around with more settings I guess.