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View Full Version : I need advice to make a shockwave.


Giap
05-14-2009, 08:11 PM
I am trying to mimic the shockwave in Iron man movie. This is the reference.

http://www.youtube.com/watch?v=6Hx6TEqrzHU

0:26 to 0:29 is what exactly I am trying to do. This is my file and the playbast

http://www.youtube.com/watch?v=8hNsbD3JfpA

and this is the scene. Please take a look and give me some advice.

http://www.mediafire.com/?sharekey=519a9a059d78618375a4fc82078ae6c8e04e75f6e8ebb871

optimus008
05-14-2009, 11:31 PM
Emit the fluid using a volumetric torus that way you can control the speed by animating the emitter. Also you can add some roll to the fluid by controlling the volume controls like along axis and away from center.

Giap
05-15-2009, 12:43 AM
Are you talking about the Emitter or about the Volume Axis Field? And could you make it clearer about the part "animating the emitter"? You mean animating the scale of the torus emitter, don't you?

Giap
05-15-2009, 05:54 AM
I think I understand your suggestion now :D This is another test with way better sim.

http://www.youtube.com/watch?v=WRO8eAK0vbI

viki164
05-15-2009, 08:27 AM
I did this sort of thing a year back in my EX-studio for a local movie & We were asked to finish 4 similar shots within a 2 weeks. have check at time 2.10 of the teaser:
http://www.youtube.com/watch?v=0AjpgVEG50w&feature=channel

basically we created 4-5 layers for tht effect
1> atmosphere dust with maya fluids
2> shockwave dust ( again 3d fluid with a torus emitter expanding over the time)
3> small debris layer
4> streaky layer stick with d ground made with 2d fluid as non-dynamic grid with high values of omplode. check the 3d nuke example in d visor for similar streaks made with fluid.

The effect culd have been more better but we were time constrained...So its OK version.
hope it helps visually!

Vik

Giap
05-15-2009, 09:03 PM
that shockwave is exactly what I am trying to mimic. But the shot I am making right now has a large scale so I wonder if I could archive with my computer? I also have a question too. How many time your resolution bigger than the size? Does resolution affect the look after render?

viki164
05-15-2009, 10:14 PM
How many time your resolution bigger than the size? Does resolution affect the look after render?


OOps! I didnt followed of wt u r saying. is it abt my resolution tht I used then I wuld say It was around 90 20 90 sumthing like tht If I remember correctly. Yes! resolution does make a big change in render!
:-)

Vik

Giap
05-15-2009, 11:37 PM
I get your resolution now. But how about the size? for example your res was 90 20 90, then what the size of the container?

I'm using a script that the container will automatically resize to fit the density and the heat. The more the size grow, the resolution also expend to keep the same ratio. For instance, my container has the size is 10 10 10 and res 30 30 30. During the animation of the fluid, the size will expand to 20 30 20, the res will auto change to 60 90 60. with this script the volume of the voxel will never change.

viki164
05-15-2009, 11:43 PM
I think I know tht script. anyway If u r growing ur container in size with resolution then there are chances tht ur sim might look lill different as the voxels increases the sim will get more refinement.
BUT...if u r tryin to make sumthing like an ironman stuff then I wuld recomend to rotate the container so tht ur Z axis will point in upward direction & u can keep it lill low in terms of resolution & thus ur simulation time will be faster & let ur Y grow toward camera which will also help u to get good swirls as it grows !
is tht make sense???
or follow ur own path :-)
Vik

Giap
05-16-2009, 04:27 AM
Can I ask you one more question. Why Z axis works better than Y axis? Do buoyancy and Gravity affect the sim or I have to use Field so compensate with Volume axis and Gravity Field?

viki164
05-16-2009, 07:14 AM
Its my own cooking method :). btw there is nothin like z axis wrks better than y axis. but Swirls are more better in Y axis as compare to in any other axis. the moment u increase ur res in Z u get a pop up window which shows sim might take a long to calculate or save ur scene..bla bla!
So its a smrt way of using ur Z usage & u keep it in a direction where Z is not used much for calculation!
cuming to fields no matter how u rotate field will always behave in same direction as of they are suppose to be.
Dude ur some of the question`s are too confusing to me. I cant understand of wt u r trying to say :-(
anyway have good time with fluids
Best
Vik

dim1984kimo
05-17-2009, 03:00 AM
http://www.vimeo.com/4334933

Do you like this ?

Giap
05-17-2009, 08:26 AM
@dim: it looks great but that's not what I am looking for. You can check the youtube link to see what exactly I am trying to mimic.


@viki: What I meant is in fluid container, there is gravity built in. I just wonder if I rotate the container, is it going to change the direction too? As buoyancy, when I change Y up to Z up and Y axis point toward to the camera, the buoyancy still affects in the Y axis instead of Z. That's why I have to use the volume axis to fake the buoyancy. Btw, thanks for sharing your the swirls info :D

darktding
05-17-2009, 06:03 PM
are you still having problem with fluids?
If so, might I suggest another way...
1) create two curves, loft them animate them going out in an a shockwave direction wrt camera
2) emit particles from lofted surface, put a fancy little texture that mimics the underlining shockwave pattern and emit from that
3) using fields and a short lifespan emit loads of particles.
4) I would do multiple sims and bake them out and render them with self shadowing on.

The really nice feature I found out recently is surface emissions give you a min and max distance; using that along with noise velocity and poisition you will get some interesting shapes

You can also go one step further, that fluid sim you have going? Reduce that resolution and use that as a field on your particles.

Anyways I would prolly use fluids, but this gives your a level of control and detail you might not get. Really it is all based on your shot/client needs.

Giap
05-19-2009, 04:06 PM
@darktding: thanks for the technique. It's really useful and I think I will use it as another layer for what I have been doing this weekend.

Actually, I have been doing a familiar method that you've just shared. I made an animated curve and a target curve. Then I use a blend shape to control the shape of the animated curve and the speed as I want it to be.

Then I make a circle and extrude along the animated curve. Use that nurb as an emitter. I also create a torus field and scale it very large cause I only use a part of it to create a rolling velocity.

Sybexmed
08-13-2009, 05:14 AM
Im doing a project of a ship launch, and this seems perfect. How did you achieve this?http://www.vimeo.com/4334933

Do you like this ?

wallabee
08-15-2009, 02:03 AM
Sorry to say, looks like he did it with Houdini's new Pyro system.

dim1984kimo
08-17-2009, 02:05 AM
Sorry to say, looks like he did it with Houdini's new Pyro system.

Yes, I am.

Sybexmed
08-17-2009, 03:28 AM
I wish there were more tutorials for houdini than what is out. Seems like it has a steep learning curve. But from what i hear, i would rather much learn fluids/particles in houdini than maya.

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