PHXSource noise spinner

[Laserschwert]

The "Noise" value in the emission section of the PHXSource object is still a mystery to me. As per the docs I understand that it randomizes the Outgoing Velocity / Inject Power / Brush Effect value, but if this is working like an animated 3D noise on the object, what's its scale or its speed? What exactly does the value of the spinner affect? Can I replicate the noise spinner with an animated noise map in the Mask slot (to get more control over speed, contrast, size), and just leave the noise spinner at zero?

[georgi.zhekov]

Hey,
Yes, you can totally use an animated noise map for a mask and leave the noise to 0.

[MANUEL_MOUSIOL]

Do the maps or the noise affect Velocity / Inject Power / Brush Effect all together ?
I was trying to get some variation via map mask only for the places where liquid is emitted but my liquid behaved totally differently .is there a way to only affect emitter places ?

[georgi.zhekov]

The mask for the Outgoing Velocity will affect the Source in either Surface Force, Volume Inject or Brush mode and it will affect where the liquid is emitted. Where it's white it will emit and where it's black it won't.

Note that the Volume Inject and Volume Brush mode are using the volume of the emitter so you will need a 3D Texture for them, where the Surface force will use the surface of the object. You can find more about it here - https://docs.chaosgroup.com/display/...+%7C+LiquidSrc

[MANUEL_MOUSIOL]

I am using surface force and with a stucco map in the mask the liquids emitter placing isnt noticably different, but the speed and amount is.
take a look:
with mask:
https://vimeo.com/264577528
without mask:
https://vimeo.com/264577489

[georgi.zhekov]

How does your mask look like?
Your grid resolution is quite low, probably that is the reason.

[MANUEL_MOUSIOL]

Right, that was it. Although I dont quite understand why that is related.
Thank you!

[georgi.zhekov]

When your grid resolution is too low - Phoenix can't sample the texture that well. It's like looking at low res photo - you can't see the details.

[MANUEL_MOUSIOL]

But wouldn't the speed of what it actually sees and shoots out be the same?

[nikola.bozhinov]

The mask modulates the outgoing velocity of the source. If the resolution is low enough and the area of the mask corresponding to high velocity is small enough the samples may not cover it, so the simulator will only "see" the parts of the mask representing low velocity.
There is only one sample per voxel, so if the mask changes within a given voxel only the part of the texture hit by the sample will matter and it depends on the alignment between the grid and the emitter. That's why at so extremely low resolutions moving the emitter or the grid even slightly may change the emission drastically. The same goes for increasing the resolution of the grid.

[MANUEL_MOUSIOL]

So there's no way to tell Phoenix with a map where to emit and where not to emit ?The velocity is always adjusted too?
the only would be to make a detailed model and give the faces different ids then ?

[Svetlin.Nikolov]

Hey,

If you plug a mask e.g. for the outgoing velocity in surface force mode, then some parts of the emitter will get more speed and some will get less. If you plug the mask under Emit Liquid, then you will get more liquid at some parts of the emitter and less or no liquid where the mask is black.

With low resolution, if your mask contains thin white zones and wider black ones, it's possible that Phoenix will hit only the black ones when reading the texture from each voxel...

Do you have the mask plugged for both ougoing velocity and emit liquid, or for only one of them?