6 replies to this topic

[thinkinmonkey]

Hello all,
I have two question about PyroFX.

1. I want to know how it's possible to "group" voxels according their temperature or velocity, so I can apply a force just to them. For example, I'd like to apply gravity only when smoke is very cold or I'd like to apply a turbulence field only to smoke (again cold voxels) and not to flames (hot voxels).

2. I'm working on a pyro simulation for a missile trail and I want flames diverge a bit, I tried some expand objects, but with no success, so I thought to create a custom velocity volume using volumevelocity. If I use a sphere with velocity according its points normals to expand gas, it behaves strangely, instead if I use a box with an upward velocity, the gas rises in a predictable way.

Thanks in advance for any help.

Attached Files

•  test_v2.hipnc   679.84K   43 downloads

[mawi]

thinkinmonkey, on 10 August 2012 - 12:59 AM, said:

Hello all,
I have two question about PyroFX.

1. I want to know how it's possible to "group" voxels according their temperature or velocity, so I can apply a force just to them. For example, I'd like to apply gravity only when smoke is very cold or I'd like to apply a turbulence field only to smoke (again cold voxels) and not to flames (hot voxels).

You can use a gas field vop to build masks, do condition-tests and manipulate velocity per voxel.
It works like a vop sop but on voxels instead of points.
I´m not on a computer with H now, but can build you a file later on if you want me to.

[thinkinmonkey]

Hi mawi,
I'll try what you say, now I'm curious about masks. About the file, if you can, I'll appreciate, but take your time, I want to try by myself!

For the second question, maybe it's quickier if I created an animated object as source volume in order to obtain  the right shape I'm looking for, but why my volumevelocity isn't working still remains a mistery for me.

[Sella]

Hi Mawi,

If you could do a test file example would be great. I am trying to do something quite similar. I am burning a building and I would love to control different fields to have more control of the effect.

Thank you very much,

[thinkinmonkey]

I'm using the GasFieldVop to add user velocity to pyro velocity when heat is lower than a given value, but it's not working.
Mawi, at this point, I'd like to see your example and understand better, thanks again.

Attached Files

•  test_flameGasVop.hipnc   774.87K   27 downloads

[mawi]

thinkinmonkey, on 21 August 2012 - 03:03 AM, said:

I'm using the GasFieldVop to add user velocity to pyro velocity when heat is lower than a given value, but it's not working.
Mawi, at this point, I'd like to see your example and understand better, thanks again.

I just had a quick look at your file and I think it would be better to mix or add your force in.
Something like heat -> fit -> ramp and then use that to mix your force/noise with solved velocity.

I can do some test, however I´m working much now and with a new kid there is not much time left.

[mawi]

Found this file I did a few weeks ago. It uses the temp field to mix in noise.

I´m not 100% sure it works as expected, but you might get the idea.

Attached Files

•  gasFieldVOP.hipnc   1.3MB   59 downloads