Vortex inconsistency

Maya
1

Hello.

I am attempting to get two emitters to produce two separate whirls in the same fluid. I have positioned them in two separate vortex fields with a cylinder volume control for each. What I want is for the rotations to occur in opposite directions. The positive magnitude works great. The negative magnitude will not match in kind - the fluid blows out. I have tweaked it - and all the gravity, damping, buoancy, etc. to no avail. Thanks in advance for your help.

2

This should work. Keep in mind that the fluid cannot move in a compressible fashion, and that limits some of the possible flows. Think of doing a rotational stir with two spoons in a tub of water.
Duncan

3

Also turn on velocity arrows to see if the vortices are affecting the fluid the way you want.

Duncan

4

Thanks for your response. Have you tried it? Are you able to get it to work? I can send you the file if you want.

I did turn on the arrows and they also show a different pattern than the positive magnitude creates.

5

I tryed it, it works... your problem might be something with 2 opposing vortexes in the same fluid....
Here's my test:

fluidEmitter -pos 0 0 0 -type omni -der 1 -her 1 -fer 1 -fdr 2 -r 100.0 -cye none -cyi 1 -mxd 1 -mnd 0 ;
// Result: fluidEmitter1 //
connectDynamic -em fluidEmitter1 fluidShape1;
// Result: fluidShape1 //
vortex -pos 0 0 0 -m 5 -att 1 -ax 0 -ay 1 -az 0 -mxd -1 -vsh none -vex 0 -vof 0 0 0 -vsw 360 -tsr 0.5 ;
// Result: vortexField1 //
connectDynamic -f vortexField1 fluid1;
// Result: fluidShape1 //
select -r fluid1 ;
setAttr "fluidShape1.velocityDraw" 1;

// Looks good now Negative...

select -r vortexField1 ;
setAttr "vortexField1.magnitude" -5;

// looks the same in the opposite direction

Again I only did one vortex field in the fluid with both posative and negative mag.

6

I tried 2 opposing vortexes in the same fluid, also sucsessful

add to the above example

vortex -pos 0 0 0 -m 5 -att 1 -ax 0 -ay 1 -az 0 -mxd -1 -vsh none -vex 0 -vof 0 0 0 -vsw 360 -tsr 0.5 ;
// Result: vortexField2 //
connectDynamic -f vortexField2 fluid1;
setAttr "vortexField2.translateX" -2.5;
setAttr "vortexField2.translateY" 0;
setAttr "vortexField2.translateZ" -2.5;
select -r vortexField1 ;
setAttr "vortexField1.translateX" 2.5;
setAttr "vortexField1.translateY" 0;
setAttr "vortexField1.translateZ" 2.5;

You get the same look in both +/-

I guess you could post your fluid and we could take a look. Because it's not the fluid vortex connection.

***if you notice slight differences try:
setAttr "fluidShape1.velocityDrawSkip" 0;
to see how they are almost exactly the same

7

Thanks. It must be because I am trying to make two vortices in one fluid - my goal is the have the whirls collide. (I am trying to set up an arty version of the different draining directions that occur on the northern vs. southern hemisphere.) It is always the negative magnitude that goes off...hmmm.

Are you sure your positive and negative samples are exactly alike?

8

well the only difference, if you copied my example into your script editor, you can see is that the posative is a little stronger in that it pushes the difference in it's direction. The area that they collide it move smoothly in the positive.
I think that if you try to have 2 vortexes collide you going to get mush. It would be too turbulent. Think about water. If you had two vortexes with different directions collide it would be violently turbulent, just like the fluid.

i think that is your problem, not the +/- on the vortexes, but how you are using them and the response you want from the fluid