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View Full Version : Are 2D fluids, and 3D fluids idential? Nuclear Explosion question


Daniel-B
07-30-2006, 08:46 PM
Hey guys. Here is what I'm trying to figure out. If I set certain properties for a 2D fluid, and I am able to generate a nuclear mushroom cloud from that, will I produce the identical mushroom cloud shape in a 3D fluid if I use the exact same settings?

I am trying to create a nuclear explosion for a film. It will take a long time to run a 3D fluid simulation at 250x250x250 grid size. Therefore, I was going to make a 2D fluid with a 250x250 grid size, and then get the simulation correct. Then I would copy those exact settings over to the 3D fluid, to get what I want. What do you guys think?

Also, there is a tutorial for using 2D fluid sims to drive particles in 3D space, much like what ILM did for Terminator 3. Here is the link....

http://web.archive.org/web/20040605100340/www.zjprogramming.com/html/fluid_particle.html

However, the plugin that allows you to do this isn't avaliable for download. I don't suppose any of you MEL guys could help me out with it?

apoc519
07-30-2006, 08:50 PM
if you can actually get a 250x250x250 fluid to simulate, then yes. It should be the same. I just don't think it's feasible. You'll be out of memory in no time not to mention the cache size will be HUGE

Daniel-B
07-30-2006, 09:10 PM
Well, unless I can get my hands on another MEL script or Plugin which can do like in the tutorial above, I guess I'm out of luck.

Thanks though.

Aikiman
07-30-2006, 09:51 PM
Do you need the plugin? I think you can use either that or the script except that the script will take a bit longer to simulate. I could be wrong.

[Edit] The script seems to work fine without the plugin.

Daniel-B
07-30-2006, 10:16 PM
Yes, I do need it. Unfortunately, the download link is broken for the plug-in and the script.

Aikiman
07-30-2006, 10:18 PM
Well I just copied the script and it works a dream! Just takes a while to simulate

Daniel-B
07-30-2006, 10:23 PM
Humm, maybe I'm doing it wrong. Care to post a scene file of what you've got so I can take a look at it?

EDIT: Ha ha, nevermind, I got it to work. Now, I wonder how I would go about rendering volumetics on top of the particles. Is there something like Afterburn for 3ds max....except for Maya?

Aikiman
07-30-2006, 10:46 PM
Google 'Overburn Maya' instead, it wont apply the volumetrics to your particle shape but it will give you an insight as to how to do it yourself.

Daniel-B
07-31-2006, 01:20 AM
Well, I have no idea how to apply a volumetric render to the particles. I've never used Maya for particles before yesturday. I've got the particles simulating through the fluid, but can't render them with volumetics.

It's so weird that they don't have anything like Afterburn for Maya. That's crazy.

Aikiman
07-31-2006, 01:43 AM
People keep saying that but once you know how the node system works, it isnt that hard at all. Try changing your particle type to cloudy and you have volumetrics as your particle shape. From here you want to open the hypershade and graph your input/output connections on your particle shape so you can see the dependency graph. Delete the cloudy particle and instead replace it with a fluid shape. Thats essentially what Overburn has done except with extra keyframing to animate the fluid shape.

If you are new to Maya dynamics, this will be very differcult to pick up and run with unless you're a complete genius. To help you kick start though open Overburn and create the 'Fire Balls' preset. In outliner make sure you open the group node so you can see the fluid shape called 'tendInd1_fluid'. Basically you should be able to middle mouse drag this into the volumetric input on your Shading Group for your explosion particle (where the cloudy particles connected to) either in hypershade or the attribute editor. Im not sure how this would work but its worth a crack.

good luck :)

[Edit] there appears to be a flaw in the process I just explained, mainly due to the fact that the new particle shape isnt driving the existing expression on the 'Fireballs' fluid shape, sorry

Daniel-B
07-31-2006, 02:04 AM
Well, I appreciate the explaination, but I'm afraid that's too difficult for me to understand since I am new to Maya. Perhaps I shouldn't have tried to jump in over my head. Thank you so much for all the help, though.

Aikiman
07-31-2006, 02:07 AM
Did you manage to download Overburn and get it going?

Daniel-B
07-31-2006, 07:23 AM
Well, I did download it, but I don't have a clue how to use it.

apoc519
07-31-2006, 07:51 AM
open your script editor and file/open the overburn.mel file. execute

Daniel-B
07-31-2006, 03:18 PM
Well, yeah, I did that. The interface comes up, but I don't know how to apply the shaders to the particles, or anything else for that matter. I've been using 3ds max for 5 years, but I'm very new to Maya (only been using it for two days) so that is why I'm having such difficulty.

Aikiman
07-31-2006, 07:29 PM
We cant really help you if you dont know your way around Maya, unfortunately not much is automated in Maya, you kinda have to make up your own workarounds which is why Maya is so powerful. That also means that its harder to just pick it up and run with it even though you can use another package well.

Daniel-B
07-31-2006, 08:33 PM
Well, I figured that would be the case. But I didn't think there was any harm in trying. I'm just trying to learn Maya. Even though I want to be a compositor, I think it's good to know 3D applications too, and I've been wanting to switch to Maya for quite some time now.

I will learn Maya over the next few months, and maybe come back to this. But thank you guys for all the help. You've been great.

Aikiman
07-31-2006, 08:38 PM
No worries, good luck! :thumbsup:

MikeRhone
07-31-2006, 09:46 PM
Shameless plug, but I tried to hit many of the basics of particles in the tutorial. It doesn't cover clouds, but if you go through it front to back and understand it, applying a 2dFluid to a particle system will be a piece of cake.

http://www.wingman.ca/tutorials/mr_spriteRig.html

Aikiman
07-31-2006, 10:04 PM
Shameless plug, but I tried to hit many of the basics of particles in the tutorial. It doesn't cover clouds, but if you go through it front to back and understand it, applying a 2dFluid to a particle system will be a piece of cake.

http://www.wingman.ca/tutorials/mr_spriteRig.html

Now, where have I seen that one before???

Ha ha ha good job Mike! I would recommend this a great read PixelMagic!

H3ro
07-31-2006, 10:49 PM
It is possible to turn a 2d Fluid into a 3d fluid, all you need to do is change one of the attribus of the fluid that is normaly hidden or something, but cant remember what it was right now...might be useful?

MikeRhone:
First of all, thanks for the tutorial you made. Exelent stuff. Would it be OK to you if I use your tutorial as a base for a MEL script? Trying to learn MEL, so I kind of need some prodjects

MikeRhone
08-01-2006, 01:04 AM
Ha ha ha good job Mike! I would recommend this a great read PixelMagic!
Heh, I did preface it with the whole "shameless plug" thing. I find myself doing that a bunch actually. Now if only I can get off my ass and post the other ones I have done :p

It is possible to turn a 2d Fluid into a 3d fluid
//To set a 2d container to a 3d one:
setAttr fluidShape1.is2d 0;

Exelent stuff. Would it be OK to you if I use your tutorial as a base for a MEL script?
Be my guest!

Daniel-B
08-01-2006, 03:39 AM
I appreciate that tutorial, Mike. I just wish it was easier to apply volumetrics to Maya particles. It looks like at this point I will just have to try to "fake" fluid motion in Max and render with Afterburn. If they had something like Afterburn for Maya, that was as easy to use, that would be great.

I'll be the first to admit that particles are not my strong point. I am more of a lighter/compositor. But we all have a strenghts and weaknesses I suppose.

MikeRhone
08-01-2006, 06:17 AM
Ya... In maya there are definately strong and weak points. From what I have found:

straight fluid effects: Look great but can be a killer to render. If you need to have long trails of smoke (Like in a meteor) the fluid container would have to be quite large. You also can't manipulate fluids as you can with normal particles PP attributes.

Regular particles: Lack the volumetric look that you can get from fluids, but are controlable on a per Particle basics. They are 'dumb particles' in that they will not self collide without some trickery, and even then its not even comparable to a fluid solve.

Fluid shaded particles: Like overburn, but on the downside they do not self shadow. (They shadow within each particle, but not over the particle system) which is a HUGE weakness (And is a bug apparently)

Particle instanced fluid containers: You can't transfer PP attributes like opacity, but they do self shadow.

Thats my tidbit of info on what conclusions I have drawn on my experiments so far. if anyone figures out a way to get around the bug, I would LOVE to hear it.

H3ro
08-01-2006, 09:22 AM
Now if only I can get off my ass and post the other ones I have done

any chance of giving some hints about what others tutorials you have made?

Daniel-B
08-01-2006, 09:51 AM
Well, here is an early version of what I came up with in 3ds max. I've got to get it looking more chaotic, but I am pleased with how the Afterburn shader is coming out.

http://img.photobucket.com/albums/v58/PixelMagic/Nuke7-18-06progression.jpg

essencedesign
08-01-2006, 04:19 PM
Going back to the beging of your thread, I don't quite see why you would need such a large resolution grid, Have you had a look at the Nuke preset? Much of what your trying to do can be acomplished with a way lower res 3D container. Just give it a try, start playing with some texturing, render out your tests with Mental Ray so the render times don't kill , and learn by doing, like all of us have ;) Good luck and be prepared to put in a bit of "headphone time"

Daniel-B
08-01-2006, 05:05 PM
Humm. Ok, I will look into that. In the mean time, what does "headphone time" mean?

essencedesign
08-01-2006, 05:08 PM
heeheee...headphone time=time to put on the headphones , some good music... and work your arse off without distraction.... :bounce:

Your Max rendering looks pretty good though :)

Aikiman
08-01-2006, 10:51 PM
Well, here is an early version of what I came up with in 3ds max. I've got to get it looking more chaotic, but I am pleased with how the Afterburn shader is coming out.


Thats is looking pretty good...I guess it boils down to getting the timing of your explosion down so that it doesn't happen too quickly. Like essencedesign said you can probably get away with a low res container but use a high frequency texture to keep your sim times down.

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