Generate smoke/particles from Pflow

[ben_hamburg]

Hi there,

not sure if there is already a description or a tutorial out there:

I have mParticles Pflow with some debris rolling around on some mesh.
The debris is supposed to "emit" smaller particles.
A known Issue with mParticles is, that I can´t emit spawn smaller particles, since the scale can´t be changed down the flow.
So I thought I might instead go with phoenix, using the bigger debris particles from my Pflow to emit the "dust"-particles (I could use the PhxFoam object and render in "point" mode, right?".

Can you quickly point me into the direction I would need to go here?

I have done something similar in the past, but it didn´t quite come out as I expected.

[Ivaylo Katev]

yes you can emit particles from pflow particles, just select the pflow event in a source that emits particles. to initiate some activity in the simulator, enable the affect velocity option.

[ben_hamburg]

Alright, I´ll check it out, thanks!
I kind of remember the last time I tried to use particles as emitter that I tried to render smoke with a modified transparency curve, but I think rendering it with a point shader will look better in this case.

[Ivaylo Katev]

the main advantage of rendering smoke with point shader is the the ability to achieve sharp smoke layers, the usual smoke is blurred by the advection.

[ben_hamburg]

Hm, not sure I´m on the right track:

So I added a PHX Simulator to the scene around the pflow particles. I left most settings except cell size and output path at its default.
I then added a PHX Source and in the "Emitter nodes" I picked all Pflow events.
I unticked "temperature" and "smoke" and instead ticked "velocity" (left it at 1) and "particles.
I inreased the particle number to 1000 and the discharge to 50.
After checking "Velocity" in the preview tab of the simulator, I could see some activity (its hard to see whats going on there though.

I then added a PHXfoam object and picked the PHX simulator as Particle System.
But when I hit render nothing was visible.

Anything I´m missing here?

[Ivaylo Katev]

you have to see red dots in the viewport during the simulation, i just made a small test and it works.
what version are you using? try to enable the option "use particle size", but in mine it works regardless of it.

[ben_hamburg]

We are on nightly build 25013.
I can see something is going on in the velocity channel, depending on how low I set the black and violet values I can even see a lot going on, bit I don´t get how I can derive whats going on particle wise here...
And it just doesn´t render anything at all.
Can you maybe send me your test scene so I can try and reverse engineer it for my setup?

[ben_hamburg]

I just noticed in the preview tab the checkbox for "other" (default color red), so I guess thats what I should see and being able to see the velocity channel doesn´t mean the particle emission is working....

[ben_hamburg]

I just made a small test myself in an empty scene and it works, so there must be something wrong with my scene....

So I just need do some error hunting now... Only thing I could think of right now is that there is something wrong because I changed the scene scale (1 unit=10 meters...I know, not very elegant, but mParticles didn´t like my real world scale, so I just used this to make the mParticles big enough to collide correctly).

[ben_hamburg]

But since I´m already here...I actually need to shade the particles somehow, they are supposed to be metallic dust, so point shader won´t work I guess...
So the question would be: Is there a way to assign a material to the particles emitted by the PHX Source...?

[Ivaylo Katev]

i don't think the scale is to blame, no idea how is this possible. what type of particles is set in your source? is it possible to be switched to foam or splash?

[ben_hamburg]

I just did another quick test and for my purpose, rendering the particles as "bubbles", making the color a dark grey and setting refractive index to 10 might work in giving them a "metallic" look.

[ben_hamburg]

No, if I switch from "drag" to "foam" or "splash" still nothing happens.
And I can confirm that scale probably isn´t the issue here.
I´ll try to pin down the problem and If I can´t find the problem I´ll strip a scene for support...

[ben_hamburg]

But I suspect the particle flow to be the issue. The mParticles integration in 3ds max 2014 is incredibly buggy...

[Ivaylo Katev]

you say there is influence over the simulation, this means the source detects them. or perhaps the activity is caused by something else?