Filling an object with a fluid

[jtk77]

ok, so far i havn;t had much luck filling an object with a fluid.
I'd like to fill up an object, save the initial state as the object, then let it slide down.
So far , I've been reading the manuals and they don;t really talk about an object filling with a fluid.
I've tried making the object a collition and then putting the emitter within and it doesn;t work that way. I'm not sure what else to do to get it to fill an object.
anyone know a way ? i saw an alias example so I'm sure its possible.

[seb-morin]

It's NOT possible in this version.
It requires a two-fluid solver (this version is only
a single fluid solver). The two fluids are air and water.
Without that, it won't work. It says so in the docs and
was confirmed by Duncan many times at SIggraph.

-Sorry!

-Perry Harovas

[jtk77]

YOU:RE KIDDING!!!.
geez, they demoed that feature...and , they even showed it off before it was released...
Every remember the liquids filling up into the maya logo?
they do seem to have a preloaded that a ball is filled with a fluid. havn't figured that one out yet..it must be a masking trick..

this really sucks. thanks though, I was pulling my hair out trying to figure it out.
Guess back to square one, the one production thing i needed fluids to do right now and nope.
Wonder how useful they truly are.

[ame]

Hello,

just because you cannot do "water" with a fluid dynamic system doesn mean that they are not usefull, you can do fire you can do smoke you can do clounds and a lot of other effect that at the time are hard to achive without a fluid dynamic system.

If you need to do a glass feeling with water you are better off getting RealFlow and if it's a project you will be able to actually pay for the software with it and next time you'll need it you will already have the the assets to do the work.

In my opinion Fluid FX is useless and they put way too much effort and money in it when other part of maya should have been upgraded and expanded but this is just my personal opinion and I'm sure there is people out there that would find so many use for fluids and be happy as hell to have it.

Later,

-a

[cloud-battery]

I don't understand why you would think this is not possible. Obviously you can only have a single fluid, but as far as making it collide with an object (which is the key part as far as I'm concerned) that's all quite doable.

I'll have to do some tests.....

[joojaa]

Didnt someone say that the maya fluids asume you are working in an atmosphere (outside presure etc)... Yes the boubles wouldnt form correctly but the fluid wuuld atlest partly do that.

But im juts guessing since i havent got a copy yet.

[jtk77]

Well i tried a good aprt of yesterday to havea fluid be comtainted within an object using collides with no luck whatso-ever . So if you guys think it can work, try it. you'll see what i mean. Plus the collides in general seeem to be touchy at best.
Yes , i think we ALL want to them to be able to do thinks like water.
In fact , there isn't a hugh point byound that. Atomospheric..fine. But to be production useful, i think a liquid is much more at this point. We can gernaly pull off fluffy clounds and smoke by other means that look almost as good and far less time comsuming ina render.
a lquid moving and dripping and rounding an object?
now thats the tuff part that i asumed they were going to tackle a year ago when we hurt about this.
Guess not. but I'm finding a use for them.
They just seem to be a "addeD" bonus rather than a "kick-ass" tool at this point.

[cloud-battery]

Of course it all depends on what is meant by "filling an object".

Do we want to see an object actually being filled? or is the emphasis on just achieving the end state, where an object has a fluid in it? Maybe so that it can then be moved/shaken/spun etc. at a later date?...

[jtk77]

well, the onyl thing that gets me is...didn;t they demo fluids filling an object?
Also a few of the demos seem to have different colored liquids interacting with each other...
Where is all of this? They holding back for maya 5 ?

[cinemafan1980]

Jtk77, are you putting the fluid emitter inside of a closed object, like a sphere? If so, the problem may be that you're trying to collide the fluid with the BACK FACES of the colliding object. Try reversing the surface normals and see what happens. I'm not sure how Maya Fluids calculates it's collision detection. If it is using the colliding objects VOLUME in the collision detection, it would surely cause problems to have the fluid emitter INSIDE the collision object. If this is the case, you wouldn't be able to fill a closed sphere with liquid from inside, but you COULD fill a cup with liquid as long as the cup had a closed surface with its normals facing outward, and you had the emitter outside of the surface. Let me know if any of this helps.

[jtk77]

acauly..I had thought somthing of that..reversing the normals...I'll try some mroe tests and let you know.
So far they do not seem to enjoy a closed surface so much. its as if some leak out , like the collide is not quite specific enough.
But i shall let you know, good ideas!

[blank-]

Hi,
You would be wasting your time if you are planning to use Maya fluids for filling a container with liquid. The polygonal mesh which Maya fluid generates is heavy & not production wise practical. I had earlier posted the same query some weeks back. Ultimately Real flow was used which is a frustrating program.
The demos of all the packages are very good but then when you sit down to do them they are very frustrating.

Goodluck

[joojaa]

No wonder einstein is reputred to tell that studying fluid mechanics is a roo complex job for any man...

[jtk77]

hah i tend to agree with you redman..i've been wasting my time with lack-luster even downright WRONG results . i am kinda disapointed..but i am finding a different use all together for the fluids than i thought..
And if i can make an oil well explotion ( that looks good) for this iraq thing i'm messing with. I will be VERY happy.

[blank-]

Hi,
Even in the Maya HTml files they have clearly mentioned that liquid pouring is not possible since you require 2 fluids, water & air.
Anyways at least you have put the fluids to some other good use.

All the best,
Redman

[jtk77]

yea I got some ideas.

[cloud-battery]

"ok, so far i havn;t had much luck filling an object with a fluid.
I'd like to fill up an object, save the initial state as the object, then let it slide down. "

The emphasis is on what happens _after_ an object has been filled - that seems to be the focus of the original post.

I imagine maybe the he/she wants to fill a logo with smoke (by whatever means necessary - forget doing that realistically) and then let the smoke-logo disperse.

As far as I can tell, that is possible with Maya fluids.

[jtk77]

acualy. I wanted to fill the logo up enough so I could turn off the geomentry. Then melt down.
So far, so good resulats..infact...no good results witha fill either. I ended up doing somthing else.,.
BUT it goes back to this thread... I want some to look into implamenting this...

http://www.highend3d.com/boards/showflat.php?Cat=&Board=MayaFluids&Number=124645&page=0&view=collapsed&sb=5&o=0&fpart=http://www.highend3d.com/boards/showflat.p...;o=0&fpart=

but anyway, I got to the point of a more solid fluid , like a mud ... and to get it without bad artifcats on the edges .. the render time for an NTSC frame was kinda silly.. as in it took a while.
So it wasn;t practical for me right now. I'm still playing with it mind you.
the deal is, I havn't gotten anything notable past the Alias examples of its use as yet...

[duncanbrinsmead]

I'm still not sure of exactly what you are after, but I think I can help a bit. When rendering a fluid you can get around problems with stepping voxellated edges with a few methods: Make the render interpolation "smooth". Also it is good if your overall density is a smooth as possible without sharp discontinuities. For example if you make your opacity graph have a hard boundary then the defined opacity( density for surfaces) will have a sudden discontinuity. By making this a smoother transition one can avoid sharp edges at voxels. Lowering the density scale and surface thresholds can also help a bit.

One way to make a logo swirl and dissolve is to import the logo as a white on black image using the paint fluids tool. Set the resolution of a 2D fluid to match your logo resolution and then import the image into the density. You can then set your 2d fluid to a surface render type. Make the size Z value larger to give the 2d fluid a little more depth and use the edge dropoff to control the roundness of the extrusion.
Duncan

[jtk77]

Definitly going to try some of that ina few!
Thats about worth an Alias tutorial eh ?
"how to mae a logo melt or whisp away with Fluids"
thanks , great advice.