This is a 3-dimensional emitter. You can position (W key), rotate (E), and scale (R) this emitter, but the scale parameters are linked and it is not possible to create oval shapes.

Speed

Here the particles' initial speed is defined in metres per second. Higher values will generate more particles per frame. Faster particles act with stronger forces on other particles or objects. The number of emitted particles also depends on your → “Resolution” settings. A value of 0.0 → stops the emission of particles.

Randomness

Use this option to avoid patterns and regular structures by displacing the particles randomly at creation time.

Fill sphere

There are two options:

With “Yes”, the viewport gizmo's volume is filled with particles and “Speed” is set to 0.
With “No”, particles will be emitted from the sphere's surface with given “Speed” value.

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