Emitter
Choose whether the particles will be emitted in the shape of a cone or pyramid.
X-Size [0..+∞m]
Y-Size [0..+∞m]
Give the size of the emitter. You can also scale the emitter by selecting the Scale tool and dragging in the viewport.
Angle Horizontal [0..360°]
Angle Vertical [0..180°]
These parameters set the value of the emission angle.
If Emitter Type is set to Cone, the horizontal range is from 0° to 90°; with the Emitter Type set to Pyramid, the horizontal range is from 0° to 360° and the vertical range is from 0° to 180°.