Nuke Explosions..for Ka-boom freaks only!

#141

Hey,Vikas Many Many Happy returns Of The Day.And Wish U happy journey To
Your Life.Happy Birth Day In Adv…And Thank For Ur Return Gift In Adv…Enjoy.

#142

Hey Neil,

     To add to the great tips from Vik and Duncan, I would suggest maybe turning down your solver quality.  100 is probably over kill. Yes a high solver quality will increase the accuracy of your sim, it pushes simulation time through the roof.  So try and find a good medium for your container.   Be very careful with using the temperature turbulence, it does a nice job of giving detail to the fluid, but like you discovered.....too much will cause noisy artifacts.
     
     I took a look at Viks scene file and, I think driving the fluids with temperature and fuel/heat is great, it certainly allows more control of the billowing shape of the fluid.  And it's a great way and an alternative to texture your fluid instead of keying the incandescence input bias.  The disadvantages of using this method is, calculation time is increased depending on your system.  The fluid also may lack irregularity within its shape, causing it to look unnatural.  All explosions drift and have distorted shapes.  It never just goes straight up.  I have been guilty of that in early tests that I have done.
     
     I did a quick test to compare fluid driven just by swirl and buoyancy to fluid driven by heat/fuel.   [http://www.vimeo.com/9459919](http://www.vimeo.com/9459919)
     
     No temperature/fuel.  Just Density and Velocity is used under contents method.  The fluid emitter also is emitting 0 heat and fuel.  I found that the fluid still maintains a nice billowing shape.  But it lacks the explosive force temperature/heat can provide.  And it also loses it's shape at the end of the sim.  You can easily make up for this by increasing your resolution so the fluid will maintain detail.  The key to utilizing swirl with high detail solve is making sure, you key your swirl parameter to a low amount after the fluid takes a nice shape.  If you leave it high throughout, your fluid sim will break on you.  I have swirl keyed at 10 to 1 from frames 1 -48.  To make up for the force, just add a volume axis field to create the explosion.  The volume axis field basically is fuel for your fluid. To fake the look of a fuel driven container with high Temperature scale, you can cheat a bit by making Temperature dynamic under Content methods keeping Fuel off.  Keep your temperature scale at a moderately low value(.5-1),  giving your emitter a very small amount of heat(.5) leaving fuel at 0, and simply keying your incandescence to shade your fluid to your liking.  
     
     I would be careful utilizing a high amounts of the density scale parameter because you want to maintain a cohesive relationship to your transparency and your opacity input bias parameters.  Density higher than 1.0                   or greater could actually be quite sudden and unnatural.  All smoke has some type of transparency.  I would probably recommend tweaking the density/voxel /sec parameter of the fluid container instead.  
     
     Notice between the two tests the advantages and disadvantages I mentioned above.  Overall I would recommend using heat/fuel to drive your explosion.  If you find a hard time creating irregular shapes of your nuke then I would suggest creating and animating a few volume axis fields or motion fields to break up the billowing movement a bit.  
      
     Basically, you can achieve a great explosion using both methods.  Just depends on your shot, how much time you have, and the system you are using.  So don't be afraid to try both or combine the two.
#143

thats shows we have two recipes for making exlosion here :thumbsup:
thanks for ur test tokanhanna, u are soul responsible for me getting into this buisness :).
My all credits goes to you bro.
This thing got devleoped on his own as I started messing or getting deeper with maya fluids & I realized that I was getting new behaviour with experimenting fuel & heat reaction. you seriously inspired me a lot to do something new. So this is it!

Anyway the technique of what I said only works best with High detail solve 0ff or except velocity mode or else in high detail solve all grids might cause blow up in an undesired way. The reason why I use to do it with the other way coz I can go high in temp turbulence & density emission.

but the best would be to combine both & thats what I have done for most of my test.
So thanks again folks, hope to see more rooms for improvements here.
Vik

#144

Hi!
I am new on Maya so I have a really basic question:
How can I make the Fluid effects by the Axis Field?
Thanx for help.

#145

wow viki that was an awesome explanation and a full-some summary seriously the whole nuke thing was so spread out that the way you have summarized it makes it a piece of cake for anyone… its a tough one still :wink: but it surely helps… man but fuel and temp are wicked … i wonder why it never rolled before and suddenly after you have mentioned that they are the key for the rolling … they just do as told… lol, anyways great going for your nuke challenge brilliant stuff as ever… i am liking aikiman’s try as well …

before i forget thanks for the scene file although i am not able to open it … is it 2010 maya? i have 2009. this has been quite a blessing as i had missed takanohanna’s file when he had linked it earlier on rapidshare… anyways … surely will have to wait what ever magic is there in your file…

but yes i have tried it even though i am just recuperating from typhoid with 102 temperature on myself lol …couldn’t wait to try it out… mom will kill me if she finds out… any ho… here’s the rolling … spent like 20 minutes on it and i guess it is rolling for starts. :slight_smile:

http://www.youtube.com/watch?v=CMJO6RwJ3_0

takanohanna … awesome smoke stuff on your vimeo… and best of luck for your training dvd’s. you have been very inspiring all the way…

guys all the best for the nuke challenge…:wavey:

#146

Maaaaaaan I just started to learn more for MAYA hair and you bring me back to fluids with all of this info.You are baaaaad baaaaad ppl(just joking xD).Thx for the info all.Definetly I will try again to make some sims :>.

#147

A old nuke test i did…

http://vimeo.com/9503774

day after my latest post. With some advice from duncan.
But need to work on the look… color etc.
Will start a new one this week, and implement new findings.

Thanks for the advice Vik, good explanation of you’re findings.

#148

Well aaaaaam I was thinking what exactly drive the fluid sim?Actualy was thinking what makes it go up or down or left or right :>.Is it Buoyancy weeeell not exactly,fields same as Buoyancy :>.Then I saw Velocity Scale I was WTF is this man so I started to experiment with it :>.I found out that you can actualy control the shape of your mushroom cap with that.Basicly its like this the three values represent x/-x,y,z/-z velocity power in the fluid :>.
So after that I was thinking what will hapen if I give it juuust a little push (you know like initial velocity in rigid bodies)and let other to the inbuild velocity.After that I remember one tutorial I think it was for blender cant remember good,where one guy was making a nuke with already made mesh and animated texture so I decide to give it a try :>.
This is what I came up with scene .Its rendered just for better view,becouse the fluid res is preaty low and with playblast you cant see anything :>.
So basicly the scene is one fluid container with emitter and one unform field that is set to 100 for the 1st 3 frames after that everything is the animated texture and the velocity that push it in the 5 directions :>.
Maybe most of you already knew that,but I wasnt and it was new for me so I decide to post it :>.Hope this will help somebody.

Edit:iIs only 3 sec,but I left it to grow and it actualy didnt lose its shape even after that xD.

#149

Hey Kdronez,

This might actually be a great find. Now are you driving your fluid with just velocity scale alone, or are you utilizing heat, fuel, and buoyancy?

#150

Its just velocity scale :>.No boyancy no heat no nothing :>.its just a simple push and fluid is driving himself(if I can say that xD).Ou and high solver was set to velocity only :>.Well anyway this have some disadvanteges,becouse this is the velocity in the fluid container so I didnt manage to do good tail,it looks like that the velocity cut “the cap” from “the tail” or smth :>.Also maybe smth like a tip make your x/-x value a little bit higher than z/-z value I think it looks better xD.
Hope this helps will try to do some more tests tommorow :>.

#151

Hey Listen u can open this file in 2009 also without any problem,First take permission from viki to use this file as study purpose then Just do this
*go to option of open and tick mark on ignore version…Done & Enjoy…

#152

@kdronez :
I have used this technique in of my test if u notice in this video :
http://www.youtube.com/watch?v=iZ9mjcb8jLQ
the last ones @ 0.36 u will see the fluid smoke has a very leading edge ( kind off streaky) & I achieved tht animating velocity scale in Y for first few frames. So it does help in achieving a lokk of what u are after! thanks for sharing anyway :slight_smile:

@fxabhi : U can open this file in maya 2009 as its an asci file so edit the file with notepad & comment out those lines wherever it says it requires maya 2010 then it should work fine.

@ruchitinfushion : No dude you dont need any permission from me. That file is a very quick basic setup which I created in a 5 mins :). feel free to use it & take it furhter. My contribution is nothing as compare to Duncan & others of what they have shared here.

hope to see more good results after lot of understanding of nuke here!
thanks everyone for sharing ur views:beer:
best,
Vik

#153

Sry man I didnt wanted to steal your idea or smth,but I just didnt know that technique like that even exist xD and it was just interesting for me :>.I’m checking the fxwars forum resently and I saw that other ppl(I dont mean maya users :> ) are aiming for rly rly slow sims and was thinking how can I achive that in maya and MAYBE this is better than changing the sim rate :>.
BTW I saw that you and Aikiman are joining forces,nice keep it up guys :>.
Ou and one question that guy designer he say that he use res 300/600/300 is this the same res like in maya fluids(was just wandering :>)?

One test at the end of the day from me xD.
fluid res is higher this time :> 90/70/90 xD.
xD

#154

Hi guys,

I’m a slight newbie to Maya (understatement of the year) and i find all of these videos very impressive. I have an assignment for my university where i have chosen to create a fire/explosion in maya, however it’s a selfstudy class and i have a hard time finding any good tutorials which tells me how to get started with this. Does any of you have any good pointers on how to get started, or ever better, some links to some good tutorials? that would really save my day!

PS. I’m using Maya 2010.

Cheers, Morten.

#155

Thanks for your input Wayne and vik,

I’ve been changing various settings and leaving renders going - just so I can get to grips with what controls what.

http://www.vimeo.com/9537487

Lowering the sim.scale obviously keeps the fluid under control but it also kills a lot of the billowing/roll. I guess if the sim scale comes down to around 0.3-0.5, other variables need cranking much higher to maintain the dynamic flow. This is probably obvious stuff to some of u but figured the more tests are posted on this forum the better.

I was playing around with the turbulence setting below velocity - however it gets ugly pretty quickly if its too high. Do people tend to leave that off/very low??

I’m trying to find a way of breaking up the top of the blast/smoke plume as it nears the end of the sim. A lot of my tests seem to end looking like ink in water - with really big smooth billows.

I tried a volume axis field with turbulence but it sent the fluid in all directions so looked unnatural. If I get any good results i’ll post them

cheers
Neil

#156

Hi guys,

just finished reading this whole thread, some really useful stuff here thanks!

I’m working on creating a simple, but accurate, gentle flame (flaming torch, candle, match etc) and came up with these:

http://vimeo.com/9573261

I think i’m getting pretty close, but i’d like to add a bit of smoke into the mix, can I do this or do i need to create a new fluid and comp them together? Struggling to get any sort of grey/black wisps at all at the moment.

#157

Well I have been watching this thread for a long time.
Amazing and impressive work.
I’m in the challenge FxNuke so I’ll be posting my tests here just to have some feedback.
Í have to warn you this is my first try so be gently. lol

http://vimeo.com/9565357

Cheers

#158

@Nwilco :

I was playing around with the turbulence setting below velocity - however it gets ugly pretty quickly if its too high. Do people tend to leave that off/very low??

yeah For explosion I normally dont use it. Its a good idea to keep it off. But the inbuilt Turb is way too useful in most cases like fire & candle flame. May be can I say its a key factor to use turbulence in candleflames & in fire sims but wont be much useful in making explosions.
try & test with low res explosion sim & see the difference. A little value might help in breaking the same.

I’m trying to find a way of breaking up the top of the blast/smoke plume as it nears the end of the sim. A lot of my tests seem to end looking like ink in water - with really big smooth billows.

Dude that`s been a problem for me too. I expect Duncan to suggest something on breaking the smooth cotton ball looks in fluid sims. I often end up with tht smooth billowing look in most of explosion tests & it happens when I dont use much temp turb with high density emission values.
the workaround as per now I think is to use a good amount of temp turbulence in conjuction with swirls.

@FluideEdge :

you are quite getting close to the flame look but if u plan to have smoke simulated with one container then u might have to increase the temperature disspation & In incandesence ramp keep the left most color to smoke color & right most to bright hot orange/yellow color.
So as the heat gets dissipated fast then shading color travels from bright to dark color depending on how u have set the incand ramp.

If you are using temperature along with fuel to give combustion effect then increase the reaction speed it gives more better transition in a dynamic way!
hope it helps
Vik

#159

VTeixeira, good start!

Nwilco, viki164 are u guys damping the explosion at all? viki164 I think u mentioned u were way back in this thread somewhere. I have had good luck with smoke billowing at the end of the explosion without using any damping. I found with it the smoke rises and then seemingly hits this invisible wall.

#160

My damping values were very small like 0.010.
still I most often get cotton ball look when I dont keep high values in temp turb/swirls.