particles items generally provide the background effects for a level like falling leaves, or snow or mist, but they are also used to provide effects such as fire, the signpost !'s and the musical notes created by the whistle.
There are 2 types of particle effect
- Ambient which cover the entire level
- Point-Source which eminate from a particular location
particles items have a position pos which only affects the Point-Source effects, and a depth attribute which allows you to control whether the effect appears in the foreground or the background.
The pretick attribute allows the particle effect to be virtually "run" for a time before the level begins. This time allows effects to "get going" or cover the level before it is displayed to the player. It was used very rarely in the original levels. The value is in milliseconds (1000 = 1second) and 1 second seems more than adequate for most cases.
Point-Source (non-ambient) Particles Library
Any of these effects could be used on a fire or signpost object, or as a particles item.
Ambient Particles Library
Any of these effects can be used on a particles item.