VFX Graph - How can I dynamically stop specific events?

I want to create X number of particle emissions.
Each emission varies in color, and position.

In my VFX Graph instance I create these emissions like so:

Code (CSharp):

1.     public void CreateEmission(Color color, Vector3 position)
2.     {
3.         VFXEventAttribute _attrib = vfx.CreateVFXEventAttribute();
4.         _attrib.SetVector3("position", position);
5.         _attrib.SetVector3("color", new Vector3(color.r, color.g, color.b));
6.         vfx.SendEvent("OnManualSpawn", _attrib);
7.     }
8.  

So let's say I call this 3 times, I now have 3 different emissions running.


Now I want to dynamically stop emission #1. How can I do this?

Currently I am instantiating and then destroying a new VFX Graph instance for every event! But this seems wrong. Is it possible to do this within a single VFX Graph instance??

 

Hey, so I've had a similar problem and solved it using the Set Alive Block on Update Particle. Since VFX Graph has not an array/list as a parameter I've also made a workaround using the bits of multiple Integer parameters, 1 particle is alive / 0 particle should die.
Since my solution only required at maximum 88 particle's IDs I've used 3 Integers (since 32bits * 3 is enough).

Explaining briefly:

In my Graph's Blackboard I have 3 Integers "Matrix" which will store the alive state for each particle ID (0-31;32-61;62-88-...). And the Id of each particle invoked per event.


For storing the particle self ID (single per event) I set the Mesh Index Attribute to my NoteIndex parameter.




[continuing in the below comment due max photos limitation]

 

[...]

Breaking it down in a single segment (0 to 31 IDs). I apply a right shift based on the index stored as meshIndex and apply a bitwise AND. To this result I compare if it is equal to 1 (alive) or 0 (to die/to stop).


Applying this to all segments:


Lastly in the code I set the particle ID in the NoteIndex parameter and update the corresponding segment/matrix before raising the Event:

Code (CSharp):

1.  
2. int notesMatrix1 = 0, notesMatrix2 = 0, notesMatrix3 = 0;
3. int noteIndexId, pressEventId;
4.  
5.     private void Awake()
6.     {
7.         pressEventId = Shader.PropertyToID("Note");
8.         noteIndexId = Shader.PropertyToID("NoteIndex");
9.     }
10.  
11.  
12.  
13.     public void ToggleNote(bool toActive, int noteIndex)
14.     {
15.         noteIndex -= 21;
16.  
17.         if (toActive)
18.             Debug.LogWarning($"Toggle Note {noteIndex}");
19.  
20.         if (noteIndex > 61)
21.         {
22.             SetMatrix(toActive, noteIndex, ref notesMatrix3);
23.             visualEffect.SetInt("NotesMatrix3", notesMatrix3);
24.         }
25.         else if (noteIndex > 31)
26.         {
27.             SetMatrix(toActive, noteIndex, ref notesMatrix2);
28.             visualEffect.SetInt("NotesMatrix2", notesMatrix2);
29.         }
30.         else
31.         {
32.             SetMatrix(toActive, noteIndex, ref notesMatrix1);
33.             visualEffect.SetInt("NotesMatrix1", notesMatrix1);
34.         }
35.  
36.         if (toActive)
37.         {
38.             visualEffect.SetInt(noteIndexId, noteIndex);
39.             visualEffect.SendEvent(pressEventId, eventAttribute);
40.         }
41.     }
42.  
43.  
44.     private void SetMatrix(bool noteActive, int index, ref int matrix)
45.     {
46.         if (!noteActive) matrix &= ~(1 << index); else matrix |= 1 << index;
47.     }

For killing the particle with the x ID, you simply set that bit to zero and update the corresponding matrix.