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arkahtek

Working on a nuclear explosion..need pointers, file and pic included

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hey guys i'm trying to get my nuclear explosion to look similar to the reference pic below on the right, my sim and composite is on the left, how can i keep heat in the mushroom cloud without changing the shape of the sim toward the end of the 240 frame sim..can someone give pointers or help me tweak my file, i'm new to houdini 11 months old lol so please break it down as simple as you can if you're giving pointers thanks ..i think i'm close but it still needs work. 

 

EDIT : This is what i have so far .. view 3rd and 4th pic.. let me know what you guys think. the explosion is 3 seconds in or 72 frames, on the  3rd frame grab. On the 4th its 4 seconds in or 96 frames

 

Edit ; HERE IS THE LATEST TAKE..low res png check the last screen shot as of january 15 1016

 

Edit latest version : Final nuke render

nuke in progress 2 hotter pt 2.hip

post-12008-0-19286900-1440613756_thumb.g

post-12008-0-38707200-1452898631_thumb.p

Edited by arkahtek

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The scene was so heavy that it would not even come up, sorry...

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@Atom

 

Just press escape as soon as the scene opens to stop the simulation and then jump to frame one. Another tip is do disable the lights to stop them for calculation the  viewport render.

 

@OP

 

So first off, in regard to my reply ti Atom, above - when saving scene's with simulations, be sure to be on frame one, else, opening it, it'll start simulation and locking up Houdini directly.

 

And I don't know what you have set up here but it's insanely heavy and if I enable OpenCL I get instant OpenCL errors and Houdini crashes. Not to be rude but I suspect most who opened scene took one look and judged it a potential rats nest and closed it down. We have no point of reference to the methodology you used setting this up at all so unless you're in production and get something like this, most - myself included - won't start digging trying to figure out what the hell it is we are looking at. :(

Edited by Farmfield

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Hey farmfeld, I have the division size set to 0.08 so maybe that's one of the problems ..I have a mid 2011 iMac which is not rated for Houdini and it works. No crashes.I'll try to set it at 0 and upload again

Edited by arkahtek

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i updated the houdini file i took some stuff out like lights etc..hopefully it won't crash on start up..try re downloading again

Edited by arkahtek

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I think i got it...let me know what you guys think of this..its not polished, and the explosion is nearly at the end of the sim at frame 159,. I also added the pyro wave i did in houdini as well, i have a mid 2011 iMac so the resolution on the sim will only go to 0.9  but you get the idea hopefully 

 

edit this the third take latest version

post-12008-0-39452700-1452898683_thumb.p

Edited by arkahtek

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I like it dude looks really cool. I think the scale is rly hard with explosions and right now your lower wave is throwing it off the most, gives it a miniature feel because of all that detail

 

Some dope reference ive found maybe itll help

 

http://i.kinja-img.com/gawker-media/image/upload/pxbdo9eld72eajxr9sw0.gif

 

http://i.imgur.com/IEaew79.jpg

 

http://petapixel.com/assets/uploads/2013/06/bombabove.jpg

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I don't think you updated the file, lights are still there and it's on frame 75 when opening the scene file.

 

About your render, a nuclear explosion is a 300m/1000ft ball of plasma that will move upwards in one piece, cooling slowly, and as it's so hot it will remain relatively unaffected by outside forces, it doesn't break up (as in your render) as it runs out of fuel, like a normal explosion - and that's why it creates that specific type of mushroom cloud, it's from the vortex created around the rising ball of plasma. A very similar thing, in regard to fluid dynamics, is a bullet exiting a gun. Much like the nuclear explosion, the forces created by the exhausted gasses and the bullet are so much bigger than outside influences, you have this very clean formation of multiple vortices being created, some from the gas movement, some from the bullet... This slowmo shot from Mythbusters shows that very clearly.

 

Edited by Farmfield

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Cool thank you guys, Alksndr, i'll check out those references, what do you suggest, do you think i should scale the wave at the bottom, making it bigger?  farmfeld you are right..i'm just stomped on how to get it to keep the heat so that the sim is unaffected. Farmfeld check out the updated file below, maybe you can  tweak the sim, i've been messing around with this sim for 3 weeks now..being a newbie 11 months in, i know there's a lot of things i don't know or understand when it comes to using specifics nodes to create something like a nuclear explosion..i actually learn better by tutorials. if you can show me what nodes to use to get the sim unaffected by outside forces that could help keep the shape in the sim.  That would be awesome. Thanks 

nuke in progress 2 hotter pt 2.hip

Edited by arkahtek

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hey atom, yea i did try it, but i wanted to try to create something myslf ..with help of course :) i was looking all over the net for a tutorial, but couldnt find one. So i came here looking for help. Were you able to download the updated file above and give it a try?

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i really think we can do this..this would help so many other people trying to make something like this...soooooo close ;) i'm still trying to tweak stuff on it..hopefully someone who downloaded the file can crack the code lol

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exactly cuenk89 thats what i'm trying to accomplish myself, can you post a pic of what yours look like so far? i would love to see what you got so far maybe we can use some pointers from each others files

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My test is so early... I propose four ways to do the top simulation, I specified in the following photo: (sorry for the size):

12034310_10205845274383923_4640465745569

I have to try the procedural texture way, it maybe a good and efficient solution. Personally I think the particle emitter would be boggy because of the resolution.

What do you think?

Edited by Cuenk89

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wowzers.. i have never even touched on procedural texturing..that is something i would have to learn. You definitely know more about that than i do. So i'll have ask you that same question ..what do you think? :)  Now i have something new to learn

This is what i have so far at 4 seconds into the pyro sim..this is all playing with the pro shelf tools adding a gas confinement node and playing with the bouyancy lift and viscosity settings mainly to get the shape

 

wowzers.. i have never even touched on procedural texturing..that is something i would have to learn. You definitely know more about that than i do. So i'll have ask you that same question ..what do you think? :)  Now i have something new to learn

This is what i have so far at 4 seconds into the pyro sim..this is all playing with the pro shelf tools adding a gas confinement node and playing with the bouyancy lift and viscosity settings mainly to get the shape

Edited by arkahtek

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I think your shape is too vertical and still there are a lot of fire.
 
I researched into the orbolt asset and I found that only 4 "big" properties were changed:
-temperature output
-gas released
-disturbance
-confinement
However, I don't know how works the CHOPS network...
I also changed cooling rate, viscosity and buoyancy and I animated timescale (be careful with this)

The final file is too simple, that's suspicious  :unsure:

 

There are so much to improve (especially the fire of the final)

Nuke_test.hipnc

  • Like 1

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