Fluid through pipelines, how would you approach it?

[olika]

Hi Phoenix-Friends,

client is requesting an animation, showing a filtration process, therefore i have to show the different steps, i.e. pumping in, filling pipe etc.
Thing is, this time it hasn`t to be physically correct but cool looking.
I think the case here is, that in real life all those pipes are already filled, hm hard to explain, but i mean there`s already pressure in it, so no wate is streaming through a empty pipe kind of thing, i hope you understand.
It`s more like opening the pipe via vraycutter and show a constant stream ( i know most simple way for it would be to try it with an animated noise shader or so) but could there be something cooler to do?
Didn`t found much in here and elsewhere (youtube vimeo) dealing around with pipelines or i was just to supid to search right but found one cool animation i really liked:
https://www.youtube.com/watch?v=sjxEFkaJRIw



But im stucked watching it and scratching my head how to create an effect like that? Is it fluid at all? Very thick? Colored Smoke? Any help or approaches very appreciated!
Thanks in advance!
Greetz Olika

[georgi.zhekov]

Hey,

It really depends on the look you are after - you can go with either smoke or liquid flowing inside the pipe.

I did something similar using smoke in this video - https://vimeo.com/156831959

There are just a few emitters in the text that are emitting smoke which is colored with a gradient.

[Svetlin.Nikolov]

Additionally, you might use a Phoenix Grid Texture loading the speed or velocity and plug it into the material color shader (if you go with liquids) or multiply the smoke color by it. Another alternative would be to use liquids with RGB output and zero RGB diffusion, and adding some noise to the source RGB. This would allow the liquid to have color variations without blending into a single color over time as it flow. For smoke this does not apply, since it naturally diffuses with time...

[olika]

Hey Georgi and Svetlin, thank you so much!
That`s some really useful tips to start from!
...wasn`t really aware of the Grid Texture, awesome!

[JuhaHo]

I'm Having the same problem. I try to visualize pulp in pipes, but once the system if filled, there seems to be no direction for the movement. It looks like fluid is trembling on spot in the pipe.

I tried to solve this by using foam with emitter, but it blew up the simulation times. Before it ran through in just a few days, now it seems to be more like one frame in a day, so total simulation would take more than four years. I think the customer will not wait that long.

Another solution was animated bump map in the liquid. That blew up the rendering times from 1/2 hour to three hours / frame / node. How did You Olika eventually solved the problem?

[georgi.zhekov]

Hey,

Instead of using foam you can pick the liquid particles in the Particle Shader and render those. This will save you a lot simulation time.

[JuhaHo]

Yes, but the particles need to be generated somehow? Is there simple workflow examples, how to bake the particles. I thought, to get particles they have to be enabled in simulation.

[georgi.zhekov]

If you have liquid - the particles are there already. By default Phoenix uses particles for the liquids so you can use those for the Particle shader.

[Svetlin.Nikolov]

Getting a day long simulation per frame means there is a huuuuuge problem with your simulation settings or the geometry in the scene. If you don't manage to improve it yourself, it would be helpful to share a screenshot your simulation settings here or to attach the scene here or send it over to Support.

Cheers!

[JuhaHo]

The simulation time blew up after I had enabled the foam. Before it, the simulation time was a one week for whole 1 200 frames. I don't think there are big problems in the scene. I have created very simple simulation model in Max and use CAD geometry only during rendering. I changed two settings: enabled foam and changed particle type from default drag to foam.

Concerning simulation times. I use HP turbo drive as my simulation drive. However on task manager, I see zero activity there, but huge activity on network and traditional hard disk drive. Does Phoenix FD use some kind caching elsewhere than my simulation drive?

[Svetlin.Nikolov]

Negative, only the Input/Output and Resimulation paths are used. If you see network activity, it might be due to license checks, but they happen only from time to time, so if it's constant, then it's something else.

If you don't want to send the scene over, the Phoenix log file would also be very helpful and should most probably show where the slowdown is.

Cheers!

[JuhaHo]

I got permission to send the file directly to You. What would be the preferred method to do that?

[georgi.zhekov]

Just send it to support@chaosgroup.com and we'll take a look.

Thank you,

[Svetlin.Nikolov]

It would be best to start with the Phoenix log though. If it's network activity, it's very likely that we won't be able to reproduce it here even using the scene.

[JuhaHo]

OK,

How do I find/generate this Phoenix log? I have sent the model to support.

At the moment I'm temporarily on another project, where I think I have found bug or at least unwanted behavior in Phoenix FD. Should I continue here, or do we need another discussion?