Particles don't collide with each other

I’m filling a glass container with ornaments. I have an emitter with a particle system, and the balls fall OK and don’t pass through the container. But the balls all land at the bottom, and go through each other, so they don’t “stack up” and fill the container. So, in short, they don’t pass through the container, but they DO pass through each other.

Particles will need to be rigid bodies. Either have the rendered ball double as the collider, or set a simplified / optimised collision object as its parent. Would suggest the latter using the sphere collider as parent to the render object.

Not sure I understand you. I have a sphere object, which is set to an active rigid body, with collision. In the particle system for the emitter (in my case, a plane), I am using the sphere object as the particles. The container is also a passive rigid body, with collision.

Sorry, was not as simple as I remembered, but liero made a test file and script that should be adaptable to your needs. (second link). Ships with cube particles but changing to spheres worked as expected.

That’s right, particles in Blender do not have the ability to collide with each other. You can use some workarounds, but it does not always work well. Also convert particles to objects and use rigid body, but it can be very heavy for blender if you have a large number of heavy meshes.

Or you can use Molecular addon (which I’m not sure if it works correctly in latest versions of blender)