Force

There are two types of forces that influence the particle's path, Gravity and Wind. The Gravity accelerates the velocity of the moving particles while Wind only provides a constant and fixed force to push the particles around.

Supported Emitters in Super Tools Library
Texture Emitter	Distortion Emitter	Ribbon Emitter	Mesh Emitter

Gravity

Set values to the three fields (X, Y and Z) in order to determine the direction of the gravity (earth gravity is -9.8). The particles will be pulled to accelerate with this force.
Before the gravity is set, the moving direction is determined by the Direction and Initial Speed in the Emitter Settings section.

After the gravity is set (Z = -9.80), the particles will be pulled by the gravity and change their directions.

Wind

Set values to the three fields (X, Y and Z) in order to determine the direction of the wind. The particles will be pushed to move in a constant speed along the wind direction.
Before the wind is set, the moving direction is determined by the Direction and Initial Speed in the Emitter Settings section.

The Wind (X/Y/Z) settings are used to set the direction of the wind. By increasing the Wind Force slider, you can set the strength of the wind.

Optionally increase the Wind Turbulence value to agitate the particles as with wind gusts. It can increase the wind's realism.