Nuke Explosions..for Ka-boom freaks only!

#81

I’m glad it is working OK for you now. I’m pretty sure I understand your original problem now. The interpolation between fluid caches is different than say interpolating position of a moving object. We simply interpolate the grid values, which is similar to doing a cross dissolve. It might be possible to do a more advanced interpolation by partially propagating density values using the grid velocities, but this would be much more complex to implement and would make cached playback slow.

When slowing down fluid caches one sometimes gets pulsing effects for a couple of reasons.

  1. A cross dissolve between two frames generally has lower contrast than the frames being interpolated. (especially if the flow is moving quickly)
  2. The interpolation is done to the raw grid values, not the final shaded values. There is usually a non-linear relationship between the grid values( density, temperature) and the shaded values (opacity, incandescence). Thus the interpolated frame might end up looking much closer to one of the frames being interpolated rather than a 50/50 blend.

There is an outstanding bug on the second issue. We could potentially compute the opacity for each voxel, interpolate that, then figure out what density would be require to produce the interpolated opacity. However this would tend to slow cached playback and is difficult to implement in the current caching architecture( which does not know about fluid shading).

A workaround is to simply slow the simulation down( for example by changing the frame rate ) and cache the full slower solution. However this can change the nature of the resulting solution.

Duncan

#82

Hey guys,
Soory for butting into your discussion.
I just wanted to extend an invitation for the next fxwars challenge.
It will be called:
“Nuke”.
Hope to see some of you in there.

The pre-challenge discussion thread is here:
Next challenge discussion.
-R
PS Duncan I am HUGE fan of your work.

#83

Hello friend this is snapshot of my nuke Explo

Here first i want to solve how to billow heavy mass of smoke with rolling movement.My solver set to all grid ex vel & swirl set to 10.

#84

This look preaty good so far,but you know when I was trying to do some nukes I found out that if you dont use that much swirl the mushrum effect is better.Instead maybe you can use some fields to brake and control your sim :>.Also IDK what you are emmiting from,but if you make a torus emiting fuel and you make another emmiter,emmiting lots of heat,and put it in the middle of the torus you can get some rly nice rezults :>.
Damn I have to try again with those nuke explosions :>.

#85


I change sphere to torus & reduce swirl 14 to 10 and now it’s start to moving nice…thnx kdronez for tips…want to move more realistic so,give me more tips…Thnx

#86

Hey ruchitinfushion,

Pretty neat so far. Looks like you are texturing with opacity, which is okay. But maybe try to sim without to see if you may get a better solution.(plus it’s faster). Increase you scale rate, and I would try a volume emitter instead of a torus. Don’t be afraid to use high swirl parameters. You can always key it off once you get the initial shape you are looking for. Looking forward to seeing more tests.

#87

ya ,i m using texture on all three …scale rate=2…and my torus is volume emitter
Texture Setting
Type=SpaceTime
Method=fix
threshold=0
Amp=1
Ratio=0.707
Freq Ratio=2
Depth Max=3
Inflection on
Texture Time=time*0.5
Freq=3
I still don’t have mastery on selection for texture type & method.
And don’t know how to tweak origin & implode…Help me

#88

Brilliant stuff vik…:thumbsup: as always

#89

Set Key to dissipation & diffusion for density…

#90

Hi guys,

This thread has been inspiring and after playing around for a few hours last night I was getting some beautiful plumes.

However, one of the basic things I couldn’t control was height! What setting controls vertical height? I tried a load and nothing worked. Every sim just goes up until it hits the top. Gravity didn’t do anything and I can’t find a ‘mass’ or similar setting.

I appreciate your time. :slight_smile:

#91

primarily : density Buoyancy and temperature buoyancy. Also you could add damp . to calm downm the simulation. It could be related to how much heat you use on the simulation.Could also be related to your simulation rate scale.

#92

Hello VIk can u plz tell me the content detail and volume axis attrb for this
mushroom explosion2

#93

Perharps you could key yours buoyancy to 0 for the first frame. Just using sdome in the first frames to make an impulse , and let the fluid properties do the rest of the sim
have you read this thread?
http://forums.cgsociety.org/showthread.php?f=86&t=741591&highlight=fume

There are a lot of tips and tricks inside.

#94

I’ll check those things out again. I didn’t play with damping so that could be it :smiley:

Cheers bud.

#95

I decide to join this great topic with 3 playblasts xD.Its basicly same sim,but with different res and some other options :>.With higher res its start to brake too much and quick still searching for solution to that :>.
clip

Sry for the bad quality T_T.Anyway hope you will like it.

#96

hey! nice sims. like the ground effect it have , nice motion.Could you describe a little your settings?

#97

At the begining I wana say that I cheat a little T_T.I used AE to time remap the sims a little(actualy almost a sec and a half :>).Anyway from a week I try to study fields in maya and how can I combine them to drive fluid/particle/nParticle sims.The settings are preaty similar to one that Vik uses for his sims(thank you Vik for sharing that info with us).I dont wana say smth that is already said,but anyway.So emitt lots of density for a few frames and use some boyancy,in my case I used 3 for boyancy and 40 for emmition rate for the 1st 10 frames and after that I key it to 6,to make the clouds rolling,the Swil was 5.Also Vik’s advice was to use Simulation Rate around 1.5-2,but that was too high for me the sim was too fast.In this 3 sims Sim Rate is .5 .I used (as he said again :> )volume axis field so I can increase the speed of the fluid.But the thing that I added from me was 2 newton field spheres(you can actualy see them for a sec in the sim)basicly it was like this I put one Newton field incide another Newton field.The one that was incide was actualy pushing the fluid away and the other one it was sucking it in.I tryed to use radial field,but it breaks the fluid too much.The magnitude of the both Newton field was -6000 for the smaller one (pushing)and 10000 for the bigger one(sucking) .So after I watched how the sim is growing I finaly put this 2 Newton fields in the fluid container at frame 23 and take them out at frame 37.so basicly they make the effect :>.For the part of the sec the fluid is braking,but becouse the newton field push it away it makes the mushroom effect.Actualy if I made the ground smoke that come after the nuke that braking part will be hidden behinde it :>.No fuel/temperature was used in the sims.

So in general this is basicly Vik’s idea,but with a little smth from me :> xD.I wana say again thank you Vik that you share your knowledge with us.

#98

Are Vik and Wayne gunna represent Maya Fluid’s and nuke FumeFX butt out of contention? Id be happy to contribute to someones project with particles/dust. Id give it a go myself but I dont have the hardware to compete :wink:

Heres the reference they are using http://www.youtube.com/watch?v=fOJppJSKG9Y& but check out the forum discussion as the rules might change.

#99

Hey Aikiman,

I may give it a go , but I have freelance work up to my neck from now till end of March. So I’ll see. :shrug:

#100

Looks like Vik’s going to give it a go, this should be good! Give those FumeFX guys a run for their money dude :slight_smile: