In Second Life, you can use particle systems to create visual effects that look like smoke, steam, dust, explosions, flames, sparks, fountains, lasers, stars, and many other things.  The Particle System Designer (PSD) is a machine to help you design your own particle systems.  It’s also a fun toy to play with

You can probably learn quite a lot about how particles work by simply playing with the PSD, but to get a good understanding of them, try visiting the Particle Laboratory.  It’s a really fun interactive museum with loads of exhibits, and it does a great job of explaining and illustrating how particles work.  Check it out!

Firstly, make sure you’re not set to Busy mode.  (If you are, the PSD won’t be able to communicate with you!)  Touch the buttons on the base of the PSD to change the various settings.  If you want to change one of the numeric settings, you’ll be asked to enter a new value using Chat.  The PSD has many demonstration particle systems built in.  To load one, simply touch the LOAD DEMO button and choose one from the list.

To show you which settings are enabled or unavailable.  In general:

Blue	Active / enabled
Red	Unavailable / disabled
Green	Currently waiting for you to supply some input using Chat, if you wish to

These specify the pattern in which new particles are emitted.

Drop	Particles are created at the emitter with no initial speed
Explode	Particles explode in all directions
Angle	Particles are emitted in a 2D (flat) fan-shaped spray, which can be partially hollow
Angle Cone	Particles are emitted in a 3D cone, which can be partially hollow
Angle Cone Empty	Second Life doesn’t display this one properly at the moment
Angle Begin	The starting angle for the “Angle” patterns, measured downwards from “straight up”
Angle End	The ending angle for the “Angle” patterns, measured downwards from “straight up”

These affect what the particles look like.

Texture	The UUID key of the texture to be used by the particles
Start Color	The colour of the particles when they’re first created
Start Alpha	The transparency of the particles when they’re first created
Interp Color	Should particles change their colour and transparency during their lifetime?
End Color	The colour of the particles just before they die
End Alpha	The transparency of the particles just before they die
Start Scale	The size of the particles when they’re first created
Interp Scale	Should particles change their size during their lifetime?
End Scale	The size of the particles just before they die
Emissive	Should the particles be self-lit (“full bright”), or should they only reflect light?
Follow Velocity	Should the particles rotate to point in the direction they’re travelling?

These affect the way in which new particles are created.

Src Max Age	The duration for new particles to be emitted (in seconds)
Burst Rate	The delay between each “burst” of particles (in seconds)
Burst Part Count	The number of particles to create in each “burst”
Burst Radius	The distance at which particles are created, measured from the centre of the emitter
Burst Speed Min	The minimum speed at which particles are emitted
Burst Speed Max	The maximum speed at which particles are emitted
Omega	The amount to rotate the particle emitter in-between each “burst”

These affect the way in which particles behave after they’ve been created.

Part Max Age	The lifetime of each particle (in seconds)
Accel	The constant acceleration applied to each particle throughout its life
Follow Src	If the particle emitter moves, should the particles move too?
Bounce	Should particles bounce if they fall to the same height as the particle emitter?
Wind	Should the particles be affected by the wind in the sim?

These control whether the particles “home in” on a specific target object.

Target Pos	Should the particles gradually “home in” on a target object?
Target Linear	Should the particles move smoothly to the target object in a straight line?
Emitter	Use the particle emitter as the target object
Other Sphere	Use the glass sphere on the right-hand pole as the target object

This makes the particle emitter rotate in a circle.  This is useful for seeing the effect of the Follow Src setting, or the Drop pattern.  It can also be helpful if you’re designing a particle system which uses a target object. Unfortunately, the rotation isn’t very smooth (because Second Life doesn’t allow hierarchies of linked prims, so I can’t make a subset of prims rotate smoothly with llTargetOmega).  Sorry about that

Simply touch the GENERATE button, and you’ll see several lines of Chat appear.  This is the LSL script to generate your particle system.  Open the Chat History window, and copy all the lines from llParticleSystem([ to ]);.  You can now paste this into a script in one of your objects.  You’ll need to delete PSD: from the beginning of each line (and the Chat timestamp too, if you’ve got this switched on in your SL preferences).  It would be better if the PSD could generate a Notecard containing the required LSL script, but unfortunately Second Life doesn’t allow this

• Whenever the PSD outputs some Chat (eg. when you touch the GENERATE button), this is actually a form of private Instant Messaging, and no-one except yourself can hear it.
• Whenever you supply an input to the PSD using Chat, this is normal public Chat and everyone nearby can hear it.
• If the PSD doesn’t seem to be behaving correctly (eg. taking a long time to react to your input), you can completely reset it, by touching the main glass sphere which emits the particles (on the end of the rotating arm).