fluid as an AIR field

[Phlok]

Hi SEVA,

maybe this thread here could be helpful:

http://forums.cgsociety.org/showthread.php?t=700949

If you have further questions, just ask.

[Cheesestraws]

Duncan says here (http://forums.cgsociety.org/showpost.php?p=5527808&postcount=338) that at one point he would like to add the ability to use a fluid as an air field and comes up with a way of emulating it within the current capabilities of maya.

[Aikiman]

Duncan says here (http://forums.cgsociety.org/showpost.php?p=5527808&postcount=338) that at one point he would like to add the ability to use a fluid as an air field and comes up with a way of emulating it within the current capabilities of maya.

Im assuming he just uses the velocity info and applies it directly as particle velocity, Im wondering if he needed to change the vectors at all, or is it a case of just raising the conserve back to 1 and letting the expressions do the rest? Have you tried it out Cheesestraws?

[Edit] I just tried it out but my code makes it run really slowly so the method is either too inpractical or my code is not very efficient, any suggestions would help a lot.



vector $pos = particleShape1.position;
int $voxels[] = `fluidVoxelInfo -v ($pos.x) ($pos.y) ($pos.z) fluid1`;
if(`fluidVoxelInfo -ib $voxels[0] $voxels[1] $voxels[2] fluid1`) {
float $vel[] = `getFluidAttr -at "velocity" fluid1`;
vector $particleVel = <<$vel[0], $vel[1], $vel[2]>>;
particleShape1.velocity = $particleVel;
}

[SEVA]

Aikiman,

My code is similiar to yours and had the same results hence my question to the board.
Thinking out loud here but may try using the inputForce of the fluid and incorprate that in the particle expression. Still trying out different ways.
In theory it seems straignt forward via the fluidVoxelInfo and getFluidAttr. Maybe not as straight forwards as one may think.

[Aikiman]

Aikiman,

My code is similiar to yours and had the same results hence my question to the board.
Thinking out loud here but may try using the inputForce of the fluid and incorprate that in the particle expression. Still trying out different ways.
In theory it seems straignt forward via the fluidVoxelInfo and getFluidAttr. Maybe not as straight forwards as one may think.

my getFluidAttr needs to include which voxels I am getting rather than the whole fluid itself, I think that should work.



vector $pos = particleShape1.position;
int $voxels[] = `fluidVoxelInfo -v ($pos.x) ($pos.y) ($pos.z) fluid1`;
if(`fluidVoxelInfo -ib $voxels[0] $voxels[1] $voxels[2] fluid1`) {
float $vel[] = `getFluidAttr -at "velocity" -xi $voxels[0] -yi $voxels[1] -zi $voxels[2] fluid1`;
vector $particleVel = <<$vel[0], $vel[1], $vel[2]>>;
particleShape1.velocity = $particleVel;
}



this works a treat!

[Duncan]

Your original expression might have been slow because getFluidAttr returns the entire fluid grid into the $vel[] array when you don't specify a specific voxel!

Duncan

[Aikiman]

Your original expression might have been slow because getFluidAttr returns the entire fluid grid into the $vel[] array when you don't specify a specific voxel!

Duncan

Hi Duncan,

thanks for dropping in...yes you are right, thanks to the wonderful F1 help I found that out and promptly added the voxel info in there. Actually I had to reboot Maya after my print command wouldnt stop printing vectors in the script editor!

[SEVA]

A thank you to Jeremy and duncan for your time and input. I managed to get my code to work and realized the same issue with "getAttr".

cheers

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