**This is an old revision of the document!**

Particles emitters

Particles emitters are used to display a large number of small particles. They simulate effects in a game. A few examples of particle emitters are fire, explosions, smoke, and dust.

The Particles Emitter object can be configured with a multitude of different parameters to create the desired effects.

Examples

Particles kind

3 rendering mode are available: Points, Lines and Textured.

  • The first mode, Points, will display circles with the specified size.
  • The second mode, Lines, will display lines with the specified length and thickness.
  • The third mode, Textured, will display an image of the specified size.

Colors

  • You can choose a starting color for particles, and a color to fade to. You can also choose a starting and final value for the transparency.

Direction of emission

Particles will be emitted in the direction represented by the angle of the emitters on the scene. You can change the angle of the spray cone, which is also represented on the scene editor by two lines: a large value for this spray cone will result in a emission of particles in a large number of directions. A value of 0 will emit particles only in a single direction.

  • Particles appears in a sphere, around the position of the emitter object. You can change the radius of the sphere.
  • Gravity can be applied on particles, on X and Y axis. For example, a negative value on Y axis will cause the particles to go up in the air.
  • Friction influences particles deceleration over time

Lifetime

  • Each particle have a limited lifetime, chosen randomly between two values which can be changed.
  • The quantity of particles contained in the emitter (“tank”) can be unlimited or fixed to a number, in which case the emitter will stop emitting after reaching this number of particles.
  • The flow is the number of particles created every seconds. You can enter -1 to fire all particles in a single shot.

You can also change the maximum number of particles rendered on screen by the object. Note that this number changes the memory taken by the emitter. If this number is really huge, it can cause the game to crash.