Yet Another Fluids Question

[pazza]

Lo there... Is there a way of using the "with curve" option in fluids but animated? I mean something like the emitt from object set to curve, but with the "with curve option".

I like how the with curve emitts, it looks a better in my tests, and you can change the radius and curve samples easily. the problem is that it emits as if the curve was staying still ( only takes the first frame into account) even though my curve is animated. Is there an expression or something that cuold make it read each frame of the curve for the emission? By the way I'm new to maya so creating scripts or expressions is beyond my knowledge.

Is it possible?? thanks in advance.

Joe

Btw. what I'm working on is a shot where two trails of smoke become a smoky couple dancing in the air ( a smoke man and woman dancing). So any tip regarding that could be helpfull I't tough to control the the smoky look of the characters without being able to recognize the curves emitting it or without having smoke all over and not recognizing a thing hehe.

[duncanbrinsmead]

It should definitely be doable. I've emitted from animated curves into fluids on several occasions in the past. It might be a dependancy graph update issues relating to the way the curve is animated. (make sure that the curve emitter is not grabbing the curve output upstream in terms of construction history from your animation)

Duncan

[pazza]

QUOTE(DuncanBrinsmead @ 09/16/05, 08:42 AM)
It should definitely be doable. I've emitted from animated curves into fluids on several occasions in the past. It might be a dependancy graph update issues relating to the way the curve is animated. (make sure that the curve emitter is not grabbing the curve output upstream in terms of construction history from your animation)

  Duncan
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I was so busy I forgot to come back here for a while. It's an honour to have an answer from you mister Duncan I'll check out what you suggest. By the way have you guys found any "trick" to make the birth of the emission more transparent than the emitted fluid. Something like animating the transparency of particles over it's life time. What I'm trying to do (withput success) is to make less noticeable the curves that emit my fluid and make the fluid it self More noticeable. I know I can play with the opacity of the fluid shading, but somehow the transission between the curves ( birth of fluid) and the fluid allready emitted is pretty hard. I'm using it based on density but that way my fluid is denser sometimes somewhere else than the zone where it is born ( in the curve) so playing with that opacity values I get "wholes" or less opaque places all over, and not in the initial emitting zone. RESUMING: is there a way to control the opacity based not on density but on the "life" of the fluid???

Thanks again Duncan...

[duncanbrinsmead]

On the fluidEmitter make the minDistance a little greater than zero( for example 0.01 ). Set the max distance such that the fluid emission occurs over at least a few voxels of the fluid. Now lower the density emission and play with the dropoff to get a smooth emission. The larger the max distance the more voxels emitted into and the slower the simulation will run.

I don't know of a simple way to have the density emit transparent then go opaque, but the above will give you smooth looking emission off of a curve( or a surface). The key is that the max distance has no effect unless the min distance is non-zero( we should really have a separate toggle, rather than rely on this non-intuitive switch ).

Duncan

[pazza]

QUOTE(DuncanBrinsmead @ 09/26/05, 03:25 PM)
On the fluidEmitter make the minDistance a little greater than zero( for example 0.01 ). Set the max distance such that the fluid emission occurs over at least a few voxels of the fluid. Now lower the density emission and play with the dropoff to get a smooth emission. The larger the max distance the more voxels emitted into and the slower the simulation will run.

I don't know of a simple way to have the density emit transparent then go opaque, but the above will give you smooth looking emission off of a curve( or a surface). The key is that the max distance has no effect unless the min distance is non-zero( we should really have a separate toggle, rather than rely on this non-intuitive switch ).

    Duncan
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Thanks again, I'll try that on my omni emitters. As for my curve emitters min and max distance don't work right? or am I wrong? I think I read that somewhere but not pretty sure. ??

Btw thanks for taking the time to help people in the forum Duncan, It's great to have an alias insider ( and scientist ) in here.

Joe

[duncanbrinsmead]

QUOTE(chesterjoe @ 09/26/05, 07:16 PM)
As for my curve emitters

[pazza]

QUOTE(DuncanBrinsmead @ 09/27/05, 09:48 AM)
Min/max distance works fine with curve emitters for me. As I said, just make sure min distance is not zero. It is important to use this with curve emitters to get a nice quality of emission.

  Ducnan
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THANKS a lot I'll try that right away. I think I read in the manual or in the help file ( don't remember) that it did not work with curve emitters, but I'm glad it does, that will help A LOT, so the min distance is the key, thank god hehe. Thanks again Duncan

Joe