The Ygdrasil User's Guide

/* particleSystem Example 5: Attractor */

light ()

particleSystem (
	emitterVolume(point -5 5 5),
	initialDirection(1 -.5 -.5 1 .5 .5),
	speed (3),
	rotation (-180 -180 -180 180 180 180),
	size (.1 .3),
	color(1 .3 0),
	emitterRate(10),
	lifespan(20),
	attractorForce("attractor1" 5 5 5 50 1),
	count(100)
)

/* particleSystem Example 6: Two Attractors */

light ()

particleSystem (
	emitterVolume(point 0 5 0),
	initialDirection(-.5 -.5 1 .5 .5 1),
	speed (3),
	rotation (-180 -180 -180 180 180 180),
	size (.1 .3),
	color(1 1 1),
	texture ("wisp.rgb"),
	emitterRate(10),
	lifespan(20),
	attractorForce("attractor1" -5 5 5 8 4),
	attractorForce("attractor2" 5 5 5 8 4),
	count(100)
)

/* particleSystem Example: Attractors, 
   one controlled by wand motion */

#include "User0"

light ()
environment(skyTopColor(1 1 1),skyBottomColor(0 0 0))

wandPosition(volume(infinite),
  when(inside,
    cube2.position($xpos 10 $zpos),
    particles1.attractorforce("attractor2" $xpos 10 $zpos 40 10))
  )
object(file(cube.pfb),position(-5 10 5))
object(file(cube.pfb),position(5 10 5))

object cube2 (file(cube.pfb),position(0 10 5))	
	
particleSystem particles1 (
	emitterVolume(box -5 5 0 5 15 10),
	emitterRate(10),lifespan(100),
	rotation(-15 -15 -15 15 15 15),
	size(.5 1.5),
	initialDirection(0 0 0 0 0 0),
	color(1 1 0),
	texture("wisp.rgb"),
	friction(1),
	count(200),
	force("gravity" 0 0 -12),
	attractorforce("attractor1" -5 10 4 100 5),
	attractorforce("attractor2" 0 10 5 100 4),
	attractorforce("attractor3" 5 10 6 100 5)
	)