Phoenix for MaYa. iPhone 12 normal size - simulation problem.

[Svetlin.Nikolov]

Hey, maybe I was not clear in my previous post:

In "phxParticleTex_set1", please use ONLY ONE "Particles_of...." node. Do not use 3 or 4 like in your video.

One more thing that might be confusing you - the particle channels, like RGB, will show in the "..." dropdown ONLY if they are present in all timeline frames. So make sure to delete your caches and to simulate again if you've just enabled the RGB channel on the Source.

And one more thing that might be the cause of issues - try editing the Particle Texture from the attribute editor and NOT from a COPY TAB. Copy tabs should be working, but you might have hit some issue.

As for the particle shading video and step by step tutorial - if you follow each step exactly, do you get a different result? I understand you are working on a different setup that is similar to the tutorials, but still is very different. If you follow the tutorial precisely and you find something different from our results, please tell me at which step it happens and we will correct it.

Thank you!

[XavBo]

To prove that is not working I did from the begining everything.
Maybe I have done something wrong, but I repeat all the steps again and again and again.

This Video is NOT speeded up.
I spend more time trying things at the end and maybe I lost at least 5 minutes trying to understand what can be wrong.

https://www.class-a-strak.com/XBO/CH..._FAQ___P02.mp4

[XavBo]

Hey, maybe I was not clear in my previous post:

In "phxParticleTex_set1", please use ONLY ONE "Particles_of...." node. Do not use 3 or 4 like in your video.

One more thing that might be confusing you - the particle channels, like RGB, will show in the "..." dropdown ONLY if they are present in all timeline frames. So make sure to delete your caches and to simulate again if you've just enabled the RGB channel on the Source.

And one more thing that might be the cause of issues - try editing the Particle Texture from the attribute editor and NOT from a COPY TAB. Copy tabs should be working, but you might have hit some issue.

As for the particle shading video and step by step tutorial - if you follow each step exactly, do you get a different result? I understand you are working on a different setup that is similar to the tutorials, but still is very different. If you follow the tutorial precisely and you find something different from our results, please tell me at which step it happens and we will correct it.

Thank you!

Hi Svetin,

I tried to repeat everything from the beginning to have a clear scene and see if this will solve the problem.
You can have a look into my Video. The last Video I share on top of this message.

Let my try your suggestions.
In my new scene I have only 1 "Particles_of...." node.

Let me have a look and I will come back to you again.

THANK YOU SOOOOO MUCH FOR THE SUPPORT !



EDIT after readying your comments:

I use MaYa since 2000 and I know that copies of Attributes cause problems or dont show everything.
The copy attributes I use for teaching or showing all I have in one screen.

If you have a look into my last video I connect the textures over the attributes and not in a copy attributes window.

I have expend 3 days doing this and trying to understand what is wrong. 3 days is a lot and I couldnt come with a result.

I understood the intention for the RGB coloring and I love it and that is why I spend that much time to see if I can make it.

You note # 1:
As you can see I have only 1 "Particles_of...." node - since I started from the scratch.

You note # 2:
I always delete the cache. I never use the "Restore". I found more convenient to clear everything and start the simulation from the beginning.
This because I found that the RGB PhoenixFDTexture and the RBG in the SimSource they both NEED to be recalculate in order to show up. It is not interactive and it is sad, because in the Video looks like the guy just run once the simulation and then started to change things.
But is not like that. I need to re-simulate if I have change the colors in any of the Textures.

You note # 3:
I already comment about the attributes-copy-window.
Im aware about this issues


Question # 1:
Yes I get at the very last step.
I dont know at all if this has to do with the fire / smoke simulation. Because in your Video you show a Liquid Sim and Im trying to do the same BUT in a Fire Sim.

If this is a problem I dont know. It shouldnt since is a change in the RGB Channel. So the fire should also work with the same technique IMHO.

When it happens?
Well everything works until I render the new re-calculated Simulation after doing all the necessary changes. That means I change the Texture Colors and I choose "RGB" from the pop-up Menu. Then I re-calculate the Simulation ...
AND THEN ... when I try to render it shows a normal white smoke.
If I turn of the GPU Preview thecolor in the Particles are appearing correctly, but the GPU color changed will not render the chosen colors.

So at the very end is happening something that the colors goes ignored.
I dont know if it is vRay or Phoeix FD.

This is out of my knowledge.



My suggestion:
You should try, because there is something that doesnt work properly.
Now I will try using a liquid to see if it works using a Liquid Sim.

But I will do this tomorrow.
I have expend already 3 days to solve the problem and I need to rest I worked 2 days not sleeping at all.

[georgi.zhekov]

Hey,

So in your last video you did everything right - you just missed to connect the Particle Shader to the drag particles.

Here is a recap of the important things:

1. Simulate your particles.

2. Create a Partricle Shader. After you create the Particle shader it needs to be connected to the Particle system you wish to render (doesn't matter if this comes from Fire/Smoke simulator or Liquid simulator, you can shade all Phoenix particle systems, even nParticles). To link the particles just select the phxParticle_set and link it to the particle system you wish to render. If you do a test render at this point your particles should be rendered white.

3. Create a Phoenix Particle Texture and connect it to the Color map slot of the Particle shader created in step 2.

4. In the settings of the Phoenix Particle texture, click the Edit Particle systems button and link the phxParticleTex_set to the particles you wish to read the shading data from. Note that both the phxParticle_set and the phxParticleTex_set need to be connected to the particles.

5. In the settings of the Phoenix Particle texture, turn on the Use Color from Particle channel checkbox and pick your channel for shading .

As Svetlin mentioned the steps will work only for a single particle system. So if you have more than one - you will need to repeat all the steps from above for each system (every system will need separate Particle shader and Particle texture).

You can also check this video of how things work - https://youtu.be/Q5uhTAGmHWo

Hope this helps!

[XavBo]

Hey,

So in your last video you did everything right - you just missed to connect the Particle Shader to the drag particles.

Here is a recap of the important things:

1. Simulate your particles.

2. Create a Partricle Shader. After you create the Particle shader it needs to be connected to the Particle system you wish to render (doesn't matter if this comes from Fire/Smoke simulator or Liquid simulator, you can shade all Phoenix particle systems, even nParticles). To link the particles just select the phxParticle_set and link it to the particle system you wish to render. If you do a test render at this point your particles should be rendered white.

3. Create a Phoenix Particle Texture and connect it to the Color map slot of the Particle shader created in step 2.

4. In the settings of the Phoenix Particle texture, click the Edit Particle systems button and link the phxParticleTex_set to the particles you wish to read the shading data from. Note that both the phxParticle_set and the phxParticleTex_set need to be connected to the particles.

5. In the settings of the Phoenix Particle texture, turn on the Use Color from Particle channel checkbox and pick your channel for shading .

As Svetlin mentioned the steps will work only for a single particle system. So if you have more than one - you will need to repeat all the steps from above for each system (every system will need separate Particle shader and Particle texture).

You can also check this video of how things work - https://youtu.be/Q5uhTAGmHWo

Hope this helps!

Hi Georgi !
I warmly appreciate the help and support you and Svetlin gave me on this one.

I got confuse at the end, but now with the video it is clear the steps to follow.

Im testing right now / Im learning all the new steps.

One thing that I dont get it and still there -> Why sometimes í have the change to choose from RGB to Position or Velocity.
Sometimes I have the choice of RGB, Position or Velocity and sometimes I got the uption of only RGB or the option of RGB or Position.

My Output is always the same for the Sim container.
Output rollout:
RBG check on
Velocity check on
Position is always check on.

But in the pop-up for the selection in the "Particles Shader" / Map Color as I said is always different the choice I can have and rarely Velocity and RGB which is the one I aim for.

BTW in the Output Particles I selct:
Liquid
Splashes
Mist
Foam
WetMap

all of them and I choose Velocity and RBG.
I play around with all of them and the pop-up Menu from the Particles Color Map doesnt show the Velocity.

[XavBo]

The "Use Color From the Particle Channel" is kind of confusing and not intuitive.
What I mean by that sis that the "Use Color From the Particle Channel" it is not at all intuitive.

You document says:

Source:
https://docs.chaosgroup.com/display/...articleTexture

Color From Particle Channel

---

Use Color From Particle Channel | colorFromPartChan– When enabled, the particle areas are colored using a specified particle channel of the connected particle system

Even if I delete and recalculate the Sim the Use Color From Particle Channel doesnt allow me to change to velocity.

Im sorry to disturb you, but for me it is weird.





EDIT !!!!!!! :

MY BAD !!!!!!
I found the way ! Since I copied all in your video I totally forgot, that I turn off the Velocity.


Hope this will help others.
To get the Velocity under the pop-up for the Use Color From Particle Channel ->MAKE SURE that you have turn on the Velocity in the "PhoenixFDSource(#)" rollout Fluid Discharge / Lifespan Variation / Output Drag Velocity.

That is the part I was missing.
Sorry my fault !

[georgi.zhekov]

Ah, glad you figured it out.

Cheers and happy simming!

[XavBo]

Hi Georgi,
Hi Svetlin,

Unfortunately I need to reopen this case.
I know it is tedious and Im so sorry about this, but unfortunately I cant understand what is going on here.

There is no logic this time and it is difficult for me to understand.

I will appreciate your Help !



This is the exact same Sim. Nothing at all change.
The only thing I did is turn on and off the " GPU Preview " and as you can see I get with the GPU turned ON 5 Sim Sources.
If I turn the GPU OFF then I see only 2 sources.

How this comes ?
GPU turned OFF
https://www.class-a-strak.com/XBO/C...001___sent.jpg

GPU turned ON
https://www.class-a-strak.com/XBO/C...002___sent.jpg


And now I tried to render the master Render Passes Layer and wrote MaYa:
Fatal Error

After the Fatal Error I render the Image again.

https://www.class-a-strak.com/XBO/C...003___sent.jpg

And this is what I mean.
As you can see clearly turning the GPU Preview OFF the Source Boxes 1,2 and 3 are not visible as a Particles in the viewport.
The Source 4 and 5 appears in the viewport as a particles.

But then in the render appears the Source 1,2 and 3 as a Smoke and not as a "Particle Color (RGB)" as chosen.

This doesnt make any sense for me.
How this happens ?
How can Im available to render Particles in RGB mode and the same time Smoke ?

[Svetlin.Nikolov]

Hey,

Let's move a few steps back. The simulator produces 3 kinds of data:
- Voxels,
- Particles
- Meshes

We are not talking about the meshes in this case, so it's important to focus on voxels and particles.

Drawing the viewport:
- Voxels (Temperature/Liquid, Smoke/Special, Velocity, etc) get shown from the Voxel Preview rollout.
- Particles are shown from the Particle Preview rollout below it.

Rendering:
- Voxels are rendered as Fire/Smoke by the Simulator node. Their shading is controlled by the settings in the Rendering -> Fire, Fire Lights, Smoke Color, Smoke Opacity rollout.
- Particles are rendered via Particle Shader nodes, connected to the Simulator.

The GPU shade preview shows the Simulator voxels, in a similar way to what will be rendered. It does not show the particles.

When turning on the GPU preview, it draws over the voxel and the particle preview, so you will not be able to see the voxel preview or the particle preview.

So from the screens you showed, I would guess that you have 5 emitters, all of them are emitting smoke voxels, all 5 are shown in the voxel and GPU previews, but only 2 of them emit Drag particles and only they are shown in the particle preview.

Is this what is happening in your setup?

Cheers!

[georgi.zhekov]

Hey,

From what I remember (please correct me if I'm wrong) in your scene you are using Discharge modifiers in the Sources for the Drag particle emission. If you remove them or if you change the settings - all of the sources should be emitting drag particles.

[XavBo]

Hi Georgi,

I will contact you as soon.

This is not the same Sim or animation.
This is from another scene.

Any issue from the iPhone 12 it is already solved.
Tis one is from a new scene.
I didnt want to open another Thread since is more or less the same thing.

[Svetlin.Nikolov]

Yup, if you are using our docs wind tunnel scene as a base - it uses discharge modifiers because there is just one emitter. If you have separate emitter geometries, you don't need the discharge modifier, so you can remove it and the source will produce particles from all geometries

[XavBo]

Hey,

From what I remember (please correct me if I'm wrong) in your scene you are using Discharge modifiers in the Sources for the Drag particle emission. If you remove them or if you change the settings - all of the sources should be emitting drag particles.

Let me check that because the Dischargers are only in the Z direction. (MaYa Z Direction)
Along the Depth/Length of the Sources.

At least is what I understand is: The Dischargers runs in the MaYa Z Direction / length of the Sources and not in the MaYa y Direction.

I use the standard MaYa axis system. There is no changes to this.


But
Strange is that the sources 123 deliver smoke instead of particles.
That means. If I have the Dischargers why they are apply to the Particles and not to the smoke.

=

123 No Dischargers detected and their for Smoke.
45 Dischargers detected and their for Particles.

Is the same Phoenix container and same Sim.

[XavBo]

Yup, if you are using our docs wind tunnel scene as a base - it uses discharge modifiers because there is just one emitter. If you have separate emitter geometries, you don't need the discharge modifier, so you can remove it and the source will produce particles from all geometries

Got it !
But I work differently and I use the Dischargers to give a bit of random Air Pressure. Kind of.

So I thought - by using dischargers, this will give me that effect of different Air Pressure.

I know I can create a lot of Geometry and Phoenix Forces and sources connected tot the Geometry, but this will a mess and I love the idea of the Dischargers !

[XavBo]

Hi Gerogi,
Hi Svetlin,

Here are my results which I dont understand completely, but I found a complex and costly solution.
Im not soooo sure if this is the way to do it, but will work. Hope so

With "Discharger" on Position Z.
https://www.class-a-strak.com/XBO/CH...004___sent.jpg

Some tries and never got the result I look for.
After many tries I decided to make everything separately. If this is the solution I dont know, but it is a lot of work doing in this way for only 1 Container that has 5 "Sources"
https://www.class-a-strak.com/XBO/CH...005___sent.jpg

BTW!
Why the simulation works ONLY in the Master layer ?
I have one "Render Pass" that has the correct geometry "the exterior of the car" and then when I run the simulation the geometry is COMPLETELY ignore.
So I need to which always to the master layer.

This is not good, because if I need to make a test with an specific shader ("Render Layer") then I need to run the simulation first in the Master Layer and after the simulation is finish, then I can switch to the "Render Layer" that I need for the "Test Render"