Particle flow Phoenix force operator problem

[larex39]

Hi Ivaylo. I wanted to mesh liquid simulation with Tninkbox Frost. So I tryed to generate particles in pflow from same spot like my liquid was and put there also phoenix force operator, first 20 frames it looks ok, particle moves exactly like it should but after liquid colide with glass, all particles stop move in this colision area. Realy it look weird, in fumefx it warks like it should but here , there is some problem. Can you please test it where can be the problem. Thanks a lot

[Ivaylo Katev]

you can try to change the integration time step of PF to a lower value, i suppose they penetrate the geometry and the velocity is zeto there.

[larex39]

Today I had time to try it, and realy when i change steps the particles start moving better, but for the lowest steps for viewport (1/8 frame) still some particles are stacked. Now i m trying render steps (1 tick) and cashing it with krakatoa, maybe it will be better, i will tell you.

The problem what i realized is that the influence parameter in phoenix force operator works only with 100 percent value, when i lower it to 99 percent it stops working. Can you confirm it please?

The second question is how i can recreate the best particle setup for similar meshing purposes like vray does but with frost. Can i use phoenix birth operator? And what exaclty means x a y axis in the graphs of this operator, it is not proper documented in helps so better for me is ask you.

Thanks a lot

[Ivaylo Katev]

yes, phoenix birth operator would be the best way in my opinion. you can produce a big quantity of particles and to delete them after 1 frame, this way you will have exactly the desired channel particle copy.
the x axis means the value of the channel controlling the birth. the y axis means probability to birth particle per unit volume per second.
for example: if you need to birth particles where you have fire, set the diagram to be like a step, with zero value at the low temperatures and high value at the high temperatures, let say above 1000 degrees.
the default diagrams produce particles at the border of the fire/smoke, not inside! if you need to produce particles inside the fire/smoke, you have to replace the bell shaped diagrams with step-like.

[larex39]

Yes but you mean static mesh, but when i want moving mesh is the phoenix birth also applicable?

Is the influence parameter in phoenix force operator working for you?

[Ivaylo Katev]

what a static mesh? not sure how to understand this.
about the influence - yes it works, i tested it right now.

[larex39]

You wrote that i will do setup with phoenix birth and after 1 frame i will delete them. But i will have only particle snapshot for this particular frame. But when I have liquid pouring animation i need something which can works also for animated particles. And I m not sure if phoenix birth can be used to do it better than i can do now. For now my setup in pflow is generate particles from face of cylinder (which is emiter also for liquid) and put there phoenix force to move it like liquid. But with this setup i have 2 problems. First is particle stucking (not moving) in place of collision (even in big substeps). Second some particles (maybe 5 percent) are moving away from liquid simulation (like in wind). So i need to know if there is a better way to set it up, to work for meshing purposes. Thanks a lot

[Ivaylo Katev]

the birth method will work with animation, every frame it creates new particles and deletes the old ones. and the best part is that they will match the liquid perfectly, no escaping and such....

[larex39]

Ok, thanks a lot a will try it, and we will see.

[larex39]

So today i tryed the phoenix birth, it does what you told me bu i have problem. I have liquid pouring simulation. My emiter stops pouring liquid after frame 100. But whatever my combine parameter is in phoenix birth operator, the particles which represents pouring stream are still there after frame 100. It looks like it is only adding new particles, but no deleting if for example temperature parameter is not met in that frame. Can you please test, because for me is not working. Thanks a lot.

[larex39]

I looked in the help and the combine parameter is not what i thought it is, but the problem is still here, particles are not deleting even if i add phoenix test operator. He is not working with phoenix birth operator. So nothing works for me now. I need some help.

[Ivaylo Katev]

no test operator is needed, delete them by age.
i did a very simple scene showing the idea

[Ivaylo Katev]

one possible problem - for some stupid reason the birth rate is limited to 10000, use the diagram to increase the birth rate, when the limit is reached, it is the same thing, the diagram is internally multiplied by the birth rate

[larex39]

Realy thanks a lot, now it is working. I have different question. Is there some way in vray or with combination with phoenix, to have simmilar fuctionality like gyzmo parameter in rendering group of phoenix. I mean I will mesh particles with frost of something different but basicly i will have polygonal mesh of fluid on each frame, and i want to cut from it the shape of my glass, to have realy smooth surface of the edges of the fluid. Is there some way to do it similarly like phoenix does. Because I have only idea to use (pro)booleans operator. Thank a lot

[Ivaylo Katev]

no idea except the boolean object.
btw, if you have vray, why you are trying to mesh the liquid?