A few questions

[Yannick]

Hi,
I have a few questions and comments on Phoenix. Sorry if the subject has been already discussed. I am using Phoenix for Maya.

Could we have a way to mesh wetmaps?
Could we have a way to export liquid particles and wetmaps particles (PRT?)?

Is there a trick when working with high spf? when seting up a scene, I work with lower grid resolution and lower spf, but for the final simulation the grid and spf are raised. However increasing the fps changes the simulation.
How can I find out what the look of the sim will be? Any tips?

Would it be possible to have a way to kill particle based on speed or on number/distance, for example if there are individual or small group of particles if they are a certain distance away, it would be be useful to be able to remove them

Any tips on how to achieve thin layer of liquid? I currently control that with the mesh controls, but I am wondering if there is a way to keep the liquid quite thin while having some surface tension?
Is there a way to control the internal pressure of a liquid? This could allow control on thin liquid effect?

Could we have a control per object on top of the global control? Some sort of multiplier in the Phoenix object attributes?

When using body force, any trick to get the liquid to perfectly fit in an object. For example, I iniatally filled an object with liquid without gravity, then let the gravity bring the liquid down, now if I remove the gravity and increase the body force effect, the liquid doesn't fill back the object, even if the liquid volume should be be the same as the object volume.

Alembic export, when exporting an alembic, Maya crashes everytime. So the only solution I found was to plug the mesh from Phoenix in to the inmesh of a geometry, but this doesn't seem to export velocity channel.

When working with small scene scale, I increase the scale in the grid but I can't seem to have a simillar result as using a large scene scale with a lower grid scale. Any tips?



Thanks,
Yannick

[georgi.zhekov]

Hello,

Currently we don't support meshing of wetmaps and PRT export in Maya I'm afraid, but both are in the to do list.

Changing the grid resolution and the steps will affect the simulation result, the solution for now is to increase them both gradually and check how it goes.
We have a liquid resimulation in the to do list, which should help with upressing the sim and keeping the same look.

The killing of the particles by speed is in the to do list as well. For now you can use Non-solid objects with Clear Inside turned on - this will kill the selected particle type that enters the volume of the geometry.

For the thin layers of liquid - you're spot on with the mesh controls. We have plans for Particle mesher which should help quite a lot with this as with the meshing of the wetmaps, but that's still to be implemented.

We do have object properties. You can find more about it here - https://docs.chaosgroup.com/display/...+FD+Attributes

Can you show us how the body force scene looks like?

The Alembic export should be working fine, what build of Maya and Phoenix are you using? Is it Windows or Linux?

For the scene scale the result really depends on the scene, you will have to scale the sources, the forces, the objects and then you will probably have the same result.

[Yannick]

Currently we don't support meshing of wetmaps and PRT export in Maya I'm afraid, but both are in the to do list.

great to know it is on the to do list.

Changing the grid resolution and the steps will affect the simulation result, the solution for now is to increase them both gradually and check how it goes.
We have a liquid resimulation in the to do list, which should help with upressing the sim and keeping the same look.

I'll give it a try. I have been working on a scene with fast moving object. But for setting up I was using low spf but when uprising, I had to resetup again as the look completely changed.

The killing of the particles by speed is in the to do list as well. For now you can use Non-solid objects with Clear Inside turned on - this will kill the selected particle type that enters the volume of the geometry.

I currently using non solid object, but sometime it is hard to get those single particles.

For the thin layers of liquid - you're spot on with the mesh controls. We have plans for Particle mesher which should help quite a lot with this as with the meshing of the wetmaps, but that's still to be implemented.

ok thanks for the info. I have noticed that if you smooth too much and have a a high iso level, the mesh get messy. it would be great if we had an option to shrink the mesh like the vdbreshape node in Houdini.

We do have object properties. You can find more about it here - https://docs.chaosgroup.com/display/...+FD+Attributes

Sorry I missed some info here, I wanted to talk about the sticky effect per object. Would be great to control that per object.

Can you show us how the body force scene looks like?

I'll try to do a simple scene to share.

The Alembic export should be working fine, what build of Maya and Phoenix are you using? Is it Windows or Linux?

I am on win 10 and using 3.10.00

For the scene scale the result really depends on the scene, you will have to scale the sources, the forces, the objects and then you will probably have the same result.

I have been trying to fill object with liquid, but the object are fairly small in Maya scale (like 10cm by 3cm by 2cm). If I was to scale the object up, it will fill it more easily, but I can't scale it up as the scene need to stay at the current scale. And increasing the grid scale doesn't seem to help.

Thanks,
Yannick

[georgi.zhekov]

Can you try the Alembic export with the latest nightly build? If it's still crashing can you send us the scene so we can check it?

[Yannick]

Can you try the Alembic export with the latest nightly build? If it's still crashing can you send us the scene so we can check it?

yes I can try that tonight. Another question, if the alembic export wasn't crashing, is it possible to export the velocity channel as well? As I need it for motion blur.

When installing the latest nightly, I cannot get Phoenix to start, when trying to load the plugin I get the following error: "The specified procedure could not be found". Anything I can do to fix this?

Thanks,
Yannick

[georgi.zhekov]

Yes, the velocity channel is exported as well Just make sure you are using the Maya Mesh option of the Simulator in the Rendering options. Note that in this mode, Phoenix will automatically create a color set for the mesh named 'phoenix_velocity'. In order to get motion blur rendering, you have to set this color set into the Mesh Shape → Mesh Controls → Motion Vector Color Set field. In order to export the mesh as Alembic with included Phoenix velocity, make to enable Write Color Sets in the Advanced Options of the Alembic Export window. Note that the 'phoenix_velocity' color set keeps the velocity in scene units per frame, in order to get the same motion blur length when rendering as Maya Mesh or as the other Mesh Type options.

[Yannick]

Yes, the velocity channel is exported as well Just make sure you are using the Maya Mesh option of the Simulator in the Rendering options. Note that in this mode, Phoenix will automatically create a color set for the mesh named 'phoenix_velocity'. In order to get motion blur rendering, you have to set this color set into the Mesh Shape → Mesh Controls → Motion Vector Color Set field. In order to export the mesh as Alembic with included Phoenix velocity, make to enable Write Color Sets in the Advanced Options of the Alembic Export window. Note that the 'phoenix_velocity' color set keeps the velocity in scene units per frame, in order to get the same motion blur length when rendering as Maya Mesh or as the other Mesh Type options.

The export worked with the latest nightly. Also something worth adding I needed to select the FDPhoenixSim node and not the PhoenixFDSimulatorMesh. I will have to test if the velocity is in it later. I had a quick look in Houdini but I can't see the channel.

[Svetlin.Nikolov]

Hey,

Did you resolve the "The specified procedure could not be found" error with the latest nightly? Are you sure you are installing a Phoenix vray3 build if you are using V-Ray 3, or a Phoenix vray4 build if you are using V-Ray Next?

Cheers!

[Yannick]

Hey,

Did you resolve the "The specified procedure could not be found" error with the latest nightly? Are you sure you are installing a Phoenix vray3 build if you are using V-Ray 3, or a Phoenix vray4 build if you are using V-Ray Next?

Cheers!

Hi,
yes fixed it, just mismatch between vray and phoenix.
Thanks

[Yannick]

When using body force, any trick to get the liquid to perfectly fit in an object. For example, I iniatally filled an object with liquid without gravity, then let the gravity bring the liquid down, now if I remove the gravity and increase the body force effect, the liquid doesn't fill back the object, even if the liquid volume should be be the same as the object volume.

Hi Regarding this question, I realized that when using the body force the liquid doesn't actually fill the object. Any chance we could get this?

What would be the best way to fill an object starting from a puddle?

Thanks,
Yannick

[Svetlin.Nikolov]

Here you go: https://docs.chaosgroup.com/display/...+%7C+BodyForce

The Spread Speed is the option you need for evenly filling an object.

Not sure what you mean by "best way to fill an object from a puddle". Is there anything in particular you want to happen that doesn't work like that with using a default body force?

Cheers!

[Yannick]

Here you go: https://docs.chaosgroup.com/display/...+%7C+BodyForce

The Spread Speed is the option you need for evenly filling an object.

Not sure what you mean by "best way to fill an object from a puddle". Is there anything in particular you want to happen that doesn't work like that with using a default body force?

Cheers!

Hi Svetlin,
I have a test scene, would you mind having a look and letting me know why the liquid doesn't fill the geo?

Thanks.

[georgi.zhekov]

Hey,

In your scene the Spread speed was a bit high and the Internal Damp was affecting the sim at the start - that's why you had an explosion and then the fill up wasn't as it should.
Here you can find the fixed scene.

[Yannick]

Hey,

In your scene the Spread speed was a bit high and the Internal Damp was affecting the sim at the start - that's why you had an explosion and then the fill up wasn't as it should.
Here you can find the fixed scene.

Thanks for this, it works very well. A scene like this should be added in the documentation. There is another thread about the description of the parameters and I also find them a bit confusing.
Cheers.

[Svetlin.Nikolov]

Indeed, this looks like a needed addition next to the morphing logo example (https://docs.chaosgroup.com/display/...Liquidmorphing).

Do you mind if we upload that scene too? It can go under the Template Scenes section where there are simpler scenes showing how specific setups work: https://docs.chaosgroup.com/display/...emplate+Scenes

Cheers!