diff --git a/direct/src/interval/ParticleInterval.py b/direct/src/interval/ParticleInterval.py
index c51b872993..a6bb5122cf 100644
--- a/direct/src/interval/ParticleInterval.py
+++ b/direct/src/interval/ParticleInterval.py
@@ -9,21 +9,52 @@ from Interval import Interval
 from direct.particles import ParticleEffect
 
 class ParticleInterval(Interval):
+    """
+    Use this interval when you want to have greater control over a
+    ParticleEffect.  The interval does not register the effect with
+    the global particle and physics managers, but it does call upon
+    them to perform its stepping.  You should NOT call
+    particleEffect.start() with an effect that is being controlled
+    by a ParticleInterval.
+    """
     # Name counter
     particleNum = 1
     # create ParticleInterval DirectNotify category
     notify = directNotify.newCategory('ParticleInterval')
     # Class methods
-    def __init__(self, particleEffect, parent, worldRelative=1, loop=0, 
-            duration=0.0, name=None):
+    def __init__(self,
+                 particleEffect,
+                 parent,
+                 worldRelative = 1,
+                 renderParent = None,
+                 duration = 0.0,
+                 softStopT = 0.0,
+                 cleanup = False,
+                 name = None):
         """
-        particleEffect is ??
-        parent is ??
-        worldRelative is a boolean
-        loop is a boolean
-        duration is a float for the time
-        name is ??
+        particleEffect is a ParticleEffect
+        parent is a NodePath: this is where the effect will be
+                              parented in the scenegraph
+        worldRelative is a boolean: this will override 'renderParent'
+                                    with render
+        renderParent is a NodePath: this is where the particles will
+                                    be rendered in the scenegraph
+                                    duration is a float for the time
+        softStopT is a float: no effect if 0.0,
+                              a positive value will count from the
+                              start of the interval,
+                              a negative value will count from the
+                              end of the interval
+                              
+        cleanup is a boolean: if True the effect will be destroyed
+                              and removed from the scenegraph upon
+                              interval completion
+                              set to False if planning on reusing
+                              the interval
+        name is a string: use this for unique intervals so that
+                          they can be easily found in the taskMgr
         """
+        
         # Generate unique name
         id = 'Particle-%d' % ParticleInterval.particleNum
         ParticleInterval.particleNum += 1
@@ -31,49 +62,72 @@ class ParticleInterval(Interval):
             name = id
         # Record instance variables
         self.particleEffect = particleEffect 
-        self.parent = parent
-        self.worldRelative = worldRelative
-        self.fLoop = loop
-        assert duration > 0.0 or loop == 1
+        self.cleanup = cleanup
+        
+        if parent != None:
+            self.particleEffect.reparentTo(parent)
+        if worldRelative:
+            renderParent = render
+        if renderParent:
+            for particles in self.particleEffect.getParticlesList():
+                particles.setRenderParent(renderParent.node())
+
+        if softStopT == 0.0:
+            self.softStopT = duration
+        elif softStopT < 0.0:
+            self.softStopT = duration+softStopT
+        else:
+            self.softStopT = softStopT
+            
         # Initialize superclass
         Interval.__init__(self, name, duration)
 
-    def __del__(self):
+    def __step(self,dt):
         if self.particleEffect:
-            self.particleEffect.cleanup()
-            self.particleEffect = None
+            self.particleEffect.accelerate(dt,1,0.05)
+
+    def __softStart(self):
+        if self.particleEffect:
+            self.particleEffect.softStart()
+        self.__softStopped = False
+
+    def __softStop(self):
+        if self.particleEffect:
+            self.particleEffect.softStop()
+        self.__softStopped = True
+
 
     def privInitialize(self, t):
-        renderParent = None
-        if self.worldRelative:
-            renderParent = render
+        if self.state != CInterval.SPaused:
+            # Restarting from a hard stop or just interrupting the
+            # current play
+            self.__softStart()
+            if self.particleEffect:
+                self.particleEffect.clearToInitial()
+            self.currT = 0
+
         if self.particleEffect:
-            self.particleEffect.start(self.parent, renderParent)
-        self.state = CInterval.SStarted
-        self.currT = t
+            for forceGroup in self.particleEffect.getForceGroupList():
+                forceGroup.enable()
+
+        Interval.privInitialize(self,t)
 
     def privStep(self, t):
-        if self.state == CInterval.SPaused:
+        if self.state == CInterval.SPaused or t < self.currT:
             # Restarting from a pause.
             self.privInitialize(t)
         else:
-            self.state = CInterval.SStarted
-            self.currT = t
+            if not self.__softStopped and t > self.softStopT:
+                self.__step(self.softStopT-self.currT)
+                self.__softStop()
+                self.__step(t-self.softStopT)
+            else:
+                self.__step(t-self.currT)
+            Interval.privStep(self,t)
 
     def privFinalize(self):
-        if self.particleEffect:
+        Interval.privFinalize(self)
+        if self.cleanup and self.particleEffect:
             self.particleEffect.cleanup()
             self.particleEffect = None
-        self.currT = self.getDuration()
-        self.state = CInterval.SFinal
-
-    def privInstant(self):
-        if self.particleEffect:
-            self.particleEffect.cleanup()
-            self.particleEffect = None
-        self.currT = self.getDuration()
-        self.state = CInterval.SFinal
-
-    def privInterrupt(self):
-        self.particleEffect.disable()
-        self.state = CInterval.SPaused
+