# How to emit particles evenly within single particle setting

How to emit particles evenly from verts / faces within single particle setting?

For example, for the default cube, I want to emit 80 particles in 10 frames, in other words, each vertex should emit 1 particle together per frame. (Note that this is a simple case to show what I'm talking about, not a specific one)

• If you have a method that is preferable to you, do you believe you should share it? Compare and contrast it? Working Blender file/script/nodes is always nice. Readers want to see the alternative. This is in reference to your comments on my proposed answer below. – atomicbezierslinger Feb 2 '16 at 7:02
• Your visual sample would be nice to see. Blender is visual. – atomicbezierslinger Feb 2 '16 at 7:15
• 1. I shouldn't have asked this question if I was satisfied with my current solution. Right? :) 2. I'm sure you got the point here, just... either your way or mine creates extra objects in order to do so, and it got some limits obviously. Now I may guess there wouldn't be any better solution, but still keep some hope on that. – Leon Cheung Feb 2 '16 at 8:17
• Interestingly enough there was a question here at BSE recently where the author seemed to have an answer immediately after posing the question. I think many people could find that question if it actually merited the time. So I did not really understand how that question fit in the "I truly need a answer" model. It was more of "let me ask and answer my own question?. I thought it was humorous. So this is a light response to your question 1. You have the freedom to choose. – atomicbezierslinger Feb 2 '16 at 15:37
• Your question 2. No I did not get any [point] prior to you writing the comment. So now I know your working state because you expressed it in a comment. – atomicbezierslinger Feb 2 '16 at 15:40

Blender Internal Render with Particle Info Node for Material Nodes

• Image below. 16 Layers of Particles Systems modified with a Python Script. Vertices of a Cube.

• Image Below. An image meant to be more readable with the particles placed in a plane. Pulsed and Batch alternating. Spiral motion is a typical consequence of the Particle System and very little effort of the Python Script.

• Image Below. Particles with Turbulence. One Force example.

• Image Below.

Technique

In the image above are 4 particle systems. You may use 10. Each Emitter particle system is copied via the Keystroke Shift+D. User preferences allows particle system to be duplicated with fresh unique copies. See user preferences Editing/Duplicate Data and enable Particle System Duplication. Of course an object can have multiple particles systems. The script assumes 1 per object for no particularly sound reason.

• If you can copy a mesh easily you can copy a mesh with a particle system easily.

• The N particles system has the [Start] and [End Value] set to different numeric value M. M >= 0 and M < N in the simplest case. See Script below.

• Copying Emitters and Manual modification of the values takes (log N + N ) steps.

• Example is Verts emission. Faces emission is an easy switch.

• Clearly if you wanted ((vertex or face) * large number) particles then a script could modify the particle system [Start] and [End] values. (frame_start, frame_end)

• The Emitters are in a group for selection convenience.

Script

• Use at your own risk. Standard Disclaimer. Please test and improve.

• Select the group of Particle System emitters before running the script.

...

import bpy
import datetime
import math

def delay_particles():
print("Delay Particles")
print(datetime.datetime.today())
print(datetime.datetime.now())

so = bpy.context.selected_objects
limit = (len(so))
n = 0
for x in range(0,limit):
so[x].particle_systems[0].settings.frame_start = n
so[x].particle_systems[0].settings.frame_end = n
n = n + 1

delay_particles()

• Thanks but what if the mesh contains thousands of verts? – Leon Cheung Feb 1 '16 at 7:07
• The script should help you in that regard. Blender is powerful. I have not tested thousands of verts for your question. That requirement should be in you original question. Please change your original question. – atomicbezierslinger Feb 1 '16 at 7:18
• You wrote verts above. Is that your intention? Did you intend to write particles? – atomicbezierslinger Feb 1 '16 at 7:28
• Tested, it seems to set start and end to 0, then all particles emit in one frame, not batches. – Leon Cheung Feb 1 '16 at 7:38
• I actually mean that how to emit particles from each elements in batches, instead of one after one or emit all in one frame. – Leon Cheung Feb 1 '16 at 8:06

Just select emit from verts under particle settings.