Best approach for Volcanic smoke?

[stevecullum]

I'm re-working one of my older scenes, trying to get it look how I wanted it to on the first place, but I'm struggling with getting a nice slow billowing motion to the smoke stack.

I want it to look as close to the smoke in the still as possible, so I thought the dynamite plugin would come in handy. But I'm struggling to get that flowing smoke look to the particles.

Maybe I'm approaching this wrong and should consider modelling the smoke shape from a cylinder or something.

Anyone else managed to produce a realistic volcano eruption - what was your method?

[SplineGod]

Id definately consider using geometry and displacement maps.

[erikals]

Displacement maps could be the thing, and even look better than HV, but they are curl-unfriendly, that is a drawback.

Did you see this eariler post?
http://www.newtek.com/forums/showthread.php?t=71979&highlight=dynamite

[HowardM]

I still vote for hvs or dynamite ;)

[HowardM]

this is reaaallly old, but perhaps you can track down Pepito or someone has his scene?
http://forums.cgsociety.org/showthread.php?f=5&t=109006&page=1&pp=20&highlight=volcano+smoke

my old test is far from perfect, flickers too much, but it shows potential...
http://www.3dink.com/smokenew.mov

if you turn off textured shadows on Volume hvs they render very fast but look nice...and you can do additional shading using gradients, and i havent used 9+ but perhaps you can do more with nodes, and Denis Ps HV nodes ;)

heres another old test that could use more work but shows potential...
http://www.3dink.com/v2.mov

[HowardM]

arggggggh! why cant we edit our freakin posts here?! :(
anyway, silly me- I had the zip all along - :D
http://www.3dink.com/pepsmoke.zip

[erikals]

Cool, had forgotten how detailed that test was,
Seems the rendertimes are high unfortunatly,
2h10m render on a DuoCore 2.4Ghz, HDTV720p

[SplineGod]

I think I would use a combination of geometry and HVs to sweeten it.
Heres a quick example I thru together to illustrate. Right now its all geometry with a cloud image in the background I found on the internet.
http://www.3dtrainingonline.com/examples/volcano_smoke.jpg

[HowardM]

Cool, had forgotten how detailed that test was,
Seems the rendertimes are high unfortunatly,
2h10m render on a DuoCore 2.4Ghz, HDTV720p

yeah, it was a real eye opener for me on how to get really nice cloudy/smoke hvs.... I dont remember if he used textured shadows, but if you turn those off and tweak some gradients you can get 'shaded' volumes that render much faster.... either way its a great start for someone to learn how to make really nice billowing hvs...

Larry- would love to see you do some magic with your methods and get some curling, billowing tendrils from geometry!

[SplineGod]

I believe in using different techniques depending on the circumstance.
This displacement on the column can be animated but typically when you have huge columns of smoke you dont see much movement unless youre quite close.
Also this can be blended with HVs or other methods as well. The nice thing is that this renders quickly and I can apply a bit of SSS to it for example. :)

[erikals]

.... I dont remember if he used textured shadows, but if you turn those off and tweak some gradients you can get 'shaded' volumes that render much faster....

Heh :) Usually I find these features, no trouble, but this time I just couldn't find it... strange, is the "textured shadows" option placed in the Hypervoxel panel? (Ctrl+F8)

[HowardM]

lol, cant rem exactly which panel (hmm someone should make a page with pics of every LW panel for reference ;)) but I think its under the Advanced tab in HVs.... Volumetric shadows will just shade the HV blob, so leave that for some simple shading... Texture shadows take forever, altho with some tweaking, perhaps set to Low, you can still use it...
You can also fake shadows or shading using gradients or colors/lighting...and of course you need Raleigh to get nice illumination from lights... ;)

[stevecullum]

Well heres what I cam up with at the time...

http://www.cullumgraphics.com/examples/VolcanoScene.mov

I didn't use any particles in the end, just painted it and animated it in after effects.

Maybe when I finish what I'm doing at the moment, I'll return to the scene and have another go.

Thanks for the links, I'll check them later when I got a bit more time.

Cheers :)

[HowardM]

hehe looks cool ;)

[stevecullum]

Thanks Howard :)

If I return to this one, then I might try adding in a pyroclastic flow with HV's or dynamite. But getting that to look right will be quite hard I think. To get the kind of volumes I've seen in reference, maybe a lot of particles will be needed too.

[erikals]

That's a really cool smoke effect :)
In this case the smoke is absolutely good enough.

[stevecullum]

Thanks Erikals. I took on board what Larry had said in an older thread, which he mentioned again here (cheers Larry ;)), that large smoke columns don't seem to move that much, so it made sense to just add some motion in AE and see what it looked like. Certainly a much harder challenge would be to replicate it from a closer distance.

[HowardM]

Thanks Howard :)

If I return to this one, then I might try adding in a pyroclastic flow with HV's or dynamite. But getting that to look right will be quite hard I think. To get the kind of volumes I've seen in reference, maybe a lot of particles will be needed too.

LOL! but HVs were made for Volcanic smoke ;)

Again I think Pepitos settings or something similar with Denis Ps HVs will get something perfect if you have time/patience... ;)

[stevecullum]

if you have time/patience

hehe...yeah I think THIS is the main thing with particleFX.

Sadly not so much time right now...*sigh*...where does the day go?

[HowardM]

ya but pepitos scene saves you like a week, use it as a start and only fine tune it, do small viper tests...etc... the particles movement is easy...or just do point morphs for total control and apply HVs.. ;)

[stevecullum]

Yeah the avi that I saw was good, but sadly the scene isnt available to download anymore. I was thinking of giving that LiquidFX a go from dstorm. I think the demo tops out at 5k particles, but I think I saw 1400 mentioned in the cgtalk thread. Might produce a more 'flowing' flow if you know what I mean?!

[erikals]

Just tesing a bit,
The first test renderes 2h10m on a DuoCore 2.4Ghz, HDTV720p,
however, if I set the render to 50%, the rendertime is 25m,
this can then be scalled up in Photoshop without too much of a visual loss, for then to use as a composite layer (so that details in the background is preserved)

If you add a QuadCore 2.6 Ghz cpu, then you might be able to cut rendertime in about half the time, a somewhat acceptable time for a SFX shot I'd say... (or...)

2h10m
http://erikalstad.com/cgtemp/pepsmoke2%202h10m.jpg
25m
http://erikalstad.com/cgtemp/pepsmoke2%2025m30sec.jpg

[erikals]

FumeFX looks to be just what the Doctor ordered though,
http://www.realflowforum.com/view_topic.php?pid=3105#p3105
http://www.roflsaurus.com/users/QBod/render2.jpg

[-EsHrA-]

LWFumeFX ..wheres the link?! :)


mlon

[HowardM]

ya fumeFX is nice, too bad Max only...

steve - the pepito scene IS there... I posted the link above in post #6...what Erikals has been showing you ;)

[stevecullum]

Doh!

Sorry, yeah I missed that post...time to get the eyes tested again :foreheads