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tious13

Attribute transfer from pyro to pop

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Hi, first of all sorry if this has already been asked.

 

    I'm advecting some particles from a pyro sim.

 

I would like to transfer some attributes from the pyro sim to the pop sim, like density, color, other... I have to use the gasfieldtoparticle node if I'm correct, but I cannot set it up correctly.

 

Here is my DOP network

 

post-14524-0-42701800-1445180247_thumb.j

 

I don't really know the correct way to use this node, could you please enlighten me ?  :)

 

[another question out of topic, do you use win10 on a work machine and do you recommend it?]

 

thanks a lot!

 

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 there are a bunch of ways to do it,  one way would be to cache your pyrosim first,  then run a popnet in a second dopnet and advect by the cached fields,  then in sops get the density values for your particles.  In this hipfile I'm using a sop solver with a point vop to sample the density values.

 

 -G

 

 

Hi, first of all sorry if this has already been asked.

 

    I'm advecting some particles from a pyro sim.

 

I would like to transfer some attributes from the pyro sim to the pop sim, like density, color, other... I have to use the gasfieldtoparticle node if I'm correct, but I cannot set it up correctly.

 

Here is my DOP network

 

attachicon.gifdop.jpg

 

I don't really know the correct way to use this node, could you please enlighten me ?  :)

 

[another question out of topic, do you use win10 on a work machine and do you recommend it?]

 

thanks a lot!

gasfield_example.hip

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As clever as the first post's network is, you need to take a look at the Spreadsheet Details view to see what is actually going on.

 

By collecting the Smoke Object DOP and the Particle Object DOP together then apply both to each solver in turn with the Multiple Solver DOP, you have two objects that contain each others data. The particle object contains all the Smoke Object fields but not enough of the meta data for the Smoke Solver to make use of it.

 

On the other hand the Smoke Object has the particle data added to the Geometry sub-data. This the POP solver can and will use. So you actually have two particle systems in your solution.

 

I know why you did this but the way DOPs work it isn't the way you wired it up. It literally shares all the data to all the solvers. Too much duplication.

It's best to have the Smoke Object DOP wire in to the Smoke Solver and the POP Object DOP wired in to the POP Solver DOP.

 

 

Now to get to your initial question: How to transfer Pyro volume attributes to points.

 

Have a look at the POP Advect By Volumes DOP.

This POP type MicroSolver DOP takes a number of volume sources and picks up by default a vector field called "vol" and uses this to affect the particles force, velocity or position.

Set the Velocity Source to DOP data and point the name to the name of your pyro simulation object.

So if you want to pick up the "vel" field from your Pyro object and map it to the particles force/vel/position, there you go.

 

Now if you want to do something other than this POP, you can unlock this HDA and dive in and rework the VOP network to your liking. All the inputs are there for you to grab and modify.

 

 

This is the most efficient method you have to do this. Yes you can copy the field data of interest on to the POP object and then directly access it as geometry but there is overhead.

 

Another approach is to point at the actual SOP geometry result in the Object that fetches the Pyro fields but again this isn't as efficient as the POP Advect By Volumes DOP approach.

 

 

The attached hip file has three DOP networks each working up their own solution. One from the shelf, one wired as you had it, and one that contains the POP Advect By Volumes DOP.

It's a good idea when learning DOPs to just copy/paste a working network then hack away. Copy as many as you want. Just remember to point all the SOP fetcher Objects to the correct DOP network when done.

Oh and don't forget to turn on the Object Display viewport option to "Hide Other Objects" so you only evaluate the current DOP network you are inside.

 

 

Hope this helps.

DOPs_pop_advect_volume.hip

Edited by old school
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Hi, first of all sorry if this has already been asked.

 

    I'm advecting some particles from a pyro sim.

 

I would like to transfer some attributes from the pyro sim to the pop sim, like density, color, other... I have to use the gasfieldtoparticle node if I'm correct, but I cannot set it up correctly.

 

Here is my DOP network

 

attachicon.gifdop.jpg

 

I don't really know the correct way to use this node, could you please enlighten me ?  :)

 

[another question out of topic, do you use win10 on a work machine and do you recommend it?]

 

thanks a lot!

So here you are, may help.

gas_pyro_field_to_pop_particle.hip

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