How to Confine Particles to a shape?

I create a sphere for my particles and set the material for the particles to “halo”.

  1. How do I keep particles confined to a shape like a glass sphere? For example if the sphere is emitting particles they fall out of the sphere. How do I keep them from exiting the sphere?

  2. How would I get particles to emit from all sides of a sphere?

  1. In the properties scene tab, turn off gravity so the particles don’t fall. Now they will just float in space, moving outwards in all directions, so in the particles tab, under velocity, set emitter geometry to 0 so the particles have no velocity and won’t move at all.

  2. By default, the particles are set to emit from the faces of the mesh object and with the above settings made, they will originate from all the faces of the sphere and just sit there not moving. So I don’t really know what you mean when you say ‘emit from all sides of a sphere?’


Thanks Randy,

Let me clarify.

  1. I would like the particles to fall/emit straight down from the top of the sphere but not go through the bottom of the sphere. So if I leave gravity on (default) how do I keep them ther particles from exiting the bottom of the sphere?

Here is an implementation that does not allow collecting of particles at the bottom, but it does keep the particles inside the sphere. Kind of like a Snow Globe.


25_snow_globe.blend (590 KB)

Here is another variation as well. This variation collects particles at the bottom, but the collisions are not perfect.


25_snow_globe.blend (449 KB)

Atom, hey thanks so much for these. The first one you posted was exactly how I set mine up but i noticed in your file and in my file some of the particles still pass through the bottom of the sphere instead of being killed on contact. I don’t know if this is a bug or something else. I will try to do a short animation to see if they “leaky” particles are rendering too.