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azshall
07-15-2008, 09:24 PM
Hey, .. I've got a question about doing a cloud layer above the horizon that would be like Mammatus clouds. They look extremely fake but are very real, however with Fluids I am only really getting a layer of clouds that is very planar on the bottom, even with texturing. Granted, they look good, they don't resemble Mammatus. Here are some images showing what those types of clouds actually look like, they're very fluid like and have a lot of noisy undulations in them.

http://www.jeffsweather.com/weatherlog/archives/mammatus2.jpg

http://epod.usra.edu/archive/images/mammatus_over_pueblo__4-_9_aug_04.jpg

http://www.pacificviews.org/weblog/archives/Pictures/lenticular_mammatus.JPG

http://www.tornadophotography.com/storms/images/MammatusClouds.jpg

Those should illustrate more what I'm looking for. I'm beginning to think that I am going to have to simulate some kind of Emission to actually get the differentiation in volume, but.. Anyone who has some insight, ..Duncan?? :) ... Thanks!

swampjesus
07-16-2008, 07:23 AM
I dont know, maybe try modeling some tube/sphere-like elements and emitting fluids from them with variable rates?

Aikiman
07-16-2008, 07:24 AM
Azshall,

Not as easy as they look...I had a play but pretty average results. Just an idea as to what may help you is to use the pond fluid and play with textures there to get instant feedback, just an idea...great shots btw.

daisukem
07-16-2008, 11:20 AM
That is a strange looking clouds!

Wixman
07-16-2008, 12:58 PM
Yeah, If I saw them recreated perfectly on a showreel i'd think

"wow, that guy has no idea how to make clouds in maya fluids"

azshall
07-16-2008, 10:05 PM
Azshall,

Not as easy as they look...I had a play but pretty average results. Just an idea as to what may help you is to use the pond fluid and play with textures there to get instant feedback, just an idea...great shots btw.

Damn, those look great! Didn't even think of messin with the pond.. I'll give it a go.. Thanks!

Aikiman
07-16-2008, 10:23 PM
Yeah, If I saw them recreated perfectly on a showreel i'd think

"wow, that guy has no idea how to make clouds in maya fluids"

LOL, thats exactly what I was thinking, in fact I think my very first attempts at fluid clouds looked similar to this and now when I actually try to recreate this effect, its really hard LOL.

Damn, those look great! Didn't even think of messin with the pond.. I'll give it a go.. Thanks!

YEah I found the pond really helpful and ended up using the Volume Wave texture with the Opacity input set to constant. My shading is pretty abysmal.

Wixman
07-17-2008, 01:19 PM
Try taking a picture of some toothpaste and mapping it on some sprites ;)

Wick3dParticle
07-17-2008, 06:04 PM
Hey people,

Those are amazing clouds!
Great attempt using the pond fluid, what was the render time?
Here is a quick test I did...using Blobby particles. Took 30 secs to render :D



~Ilan

Aikiman
07-17-2008, 07:17 PM
Hey people,
Those are amazing clouds!
Great attempt using the pond fluid, what was the render time?
Here is a quick test I did...using Blobby particles. Took 30 secs to render :D
~Ilan

Its actually using a gradient fluid in the final render, the pond was just used to get the settings for the texture. Render time approx 15 secs.

CLONEOPS
07-17-2008, 08:12 PM
Okay i don't have a any fluid sim available and not a Maya user.. but as a little observational tip i would suggest looking at a fairly common interaction.

item 1- a hot cup of coffee,i mean microwave 3 minutes hot,. let it sit for 8 minutes do not touch it externally at all so that it gets to a sort of stable state.
item 2- cold cream not milk ,really cold cold but not frozen.
3. action -pour that cream really slowly into the center of the cup slowly if you will,i would say about 4 tablespoons...the cold cream will hit the bottom then will rise due to thermal but will maintain within it's own boundary until the value of the exterior thermal forces overcome it.

What you should see is something very very similar to the effect of a mammatus and if you did it right the effect should happen "fairly" slowly..of course the effect is rising so you would have to invert the cup to have a complete simulated mammatus..i don't suggest doing this:)

So 2 fluids interacting is a step in the right direction i think, the density/viscosity could probably be tweaked to simulate any temperature variation,but really what this looks like is something a fire effect sim would do best...only slowly..the same effect is seen in "extremely" hot gases gathering at a ceiling..they take on that dense liquid roiling appearance microseconds before the ignition event.

Looks like the real thing is a cyclic interaction of heat exchange around very dense well defined thermal boundary layers and some seriously solid convection cutting.

..on second thought smoke within a fluid environment might be the answer.

Probably too much info maybe.:shrug:

Aikiman
07-17-2008, 09:13 PM
all 30secs render

Wick3dParticle
07-17-2008, 09:15 PM
They look Awesome!!! Great Job!

~Ilan

spiralof5
07-21-2008, 10:07 PM
try and look at this..........it might give some better insite.......straight from the man duncan.

http://area.autodesk.com/index.php/blogs_duncan/blog_detail/volume_displacement_method_for_clouds_using_fluids/

I haven't tried it yet but I think I will tomorrow.

Cheerz

azshall
07-22-2008, 01:45 AM
all 30secs render

Great work man!! It would appear as if you've nailed it!

Aikiman
07-22-2008, 02:26 AM
Just a quick note, the fluid has been flipped 180˚ to get the gradient in -Y.

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