Maya smoke help Please!

#1

Hey guys,

I have been trying to emit particles from an emitter that is following a rocket to act as the smoke trail. I keep having a few problems. When I scrub through, since the rocket is fast, the smoke looks like little poofs or blobs; almost like they are only being emitted on every single frame. I have put the Substeps to 32 and checked “Emit In Substeps”. I have also clicked on the 3D fluid container and went to the Dynamcis tab, Solvers, “Edit Oversampling or Cache Settings
” and changed that to 32 as well. Lastly I thought not enough particles were being emitted so I changed to rate from 5000 to 10000. This is the first rocket and is only 18 frames, the second rocket does the same thing but once I figure the first out I’m sure it will be quite similar. The other thing is when I take a render of the smoke it looks very blocky. I believe that is the voxels showing up. I have the resolution as the following:

Base Resolution: 200

Resolution: 122, 18, 14

Size: 55, 15, 25

I can put the Base Resolution to 400 which almost reaches my systems max but slightly increases the quality. It seems to work better when I slow down the rockets speed. I don’t want to do that because that would be a super slow rocket. :slight_smile:

Any help on this would be greatly appreciated.

Thanks in advance!

Aaron.

http://postimg.org/image/u2dor7aej/

http://postimg.org/image/cfbq7o4lv/

#2

What happens if you try to cache the fluid in substeps, e.g 10 substeps?
There is a difference between fluid internal substeps and playback/cache substeps.

Maybe turning on motion streaks for your particles can help as well.

#3

Is the substeps for the cache set in the “Fluid nCache Options” or does the Cache settings in the Solver tab do that? I see that in the Cache Options there are options for “Evalute every __ frame(s)” and “Save every __ evaluation(s)” would those have any effect? Also, if I were to render a cached fluid, would the cached substeps be included in the final render?

I’m quite new to fluids,

Thanks!

#4

If my above is correct, this slightly fixes the problem. I’m trying again with more SubSteps.

I need this fixed by Friday, I’ll check in later. Thanks!

#5

To get rid of the blockiness in the render do this.

Go to your fluidshape and scroll down to render quality.
Set the render interpolator to smooth instead of linear.

That should do it.

#6

Another question, what kind of emitter are you using? Are you emitting regular particles that is in turn emitting fluids? or are you just using a regular fluid emitter

#7

The “Smooth” setting seems to help quite a bit. I’m using a FluidEmitter set as Omni.

#8

Okay, so I have the “blobs” figured out. Now I am just having problems with the “Smokey look” if that makes any sense.

These are the settings I am using. I will connect a wind force later at the end to blow everything out of the scene.

#9

hard to give any advice when we dont know what style or look you want, post some ref pics of what you are trying to acheive and people will have a lot better chance to help you =)

#10

Okay so I’m looking for something like this when the rocket is going through the air.
http://media.thegnomonworkshop.com/interview/wispySmoke.jpg

After I was wanting it to look like this when the smoke rolls around and eventually fades off.
http://www.exocortex.org/ben/gallery05/smokeComparison.png

Realistically something that looks like actual smoke instead of this smokey jello. :slight_smile:

#11

are you using the motion streak in the emitter???

#12

Yes, I am using Motion Streak. If anyone is able to could you suggest some settings I could try? I’m not sure if you barely need to touch the values or if they need higher values to react.

Thanks in advance.

#13

I believe jitter has to be off for motion streak to work. Have you tried in increasing velocity swirl and noise? Is this going to be on fire? once you add temperature and fuel you sim will change.

#14

Okay I have Jitter turned off. I increased velocity swirl and noise but when I pass 8 on all three settings the smoke breaks up into smaller pieces and doesn’t act like smoke anymore. I’d like the start of the smoke to have a little fire in it because it’s being emitted from a rocket. I’m playing around with Temperature and Fuel but I have no idea where to start so I’m just trying different values to see what happens.

#15

8 is pretty high. I probably wouldn’t go over 5 on swirl and keep noise less than one but you’ll have to experiment to decide.

Temperature and fuel are going to affect you velocity which will change the sim so be ready to tweak your settings (also, fuel effects temperature which in turn effects fuel).

Have you considered using fluid shaded particles for this? SOuP has overburn which is good for this sort of thing.

#16

Got it all working. To the people who commented, thanks a bunch!

#17

2 very important things…

1)inherit velocity on particle system (anywhere from 0.0-1.0).
2) inherit velocity of particles in the fluid emitter (in the emission speed attributes and turning speed method to ‘add forces’ and inherit velocity to 1.0)

experiment with the particles inherit speed.

this should add a lot of interesting details and movement. if you want to post a scene, i’d be happy to have a look at it.

#18

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