diff --git a/direct/src/interval/ParticleInterval.py b/direct/src/interval/ParticleInterval.py
index c51b872993..c84c82f320 100644
--- a/direct/src/interval/ParticleInterval.py
+++ b/direct/src/interval/ParticleInterval.py
@@ -14,16 +14,26 @@ class ParticleInterval(Interval):
     # 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 ??
+        particleEffect is a ParticleEffect
+        parent is a NodePath
         worldRelative is a boolean
-        loop is a boolean
+        renderParent is a NodePath
         duration is a float for the time
-        name is ??
+        softStopT is a float
+        cleanup is a boolean
+        name is a string
         """
+        
         # Generate unique name
         id = 'Particle-%d' % ParticleInterval.particleNum
         ParticleInterval.particleNum += 1
@@ -31,25 +41,39 @@ 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.softStopT = softStopT
+        self.cleanup = cleanup
+        
+        if parent != None:
+            self.particleEffect.reparentTo(parent)
+        if worldRelative:
+            self.particleEffect.setRenderParent(render.node())
+        
         # 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 start(self, *args, **kwargs):
+        self.state = CInterval.SInitial
+        if self.particleEffect:
+            self.particleEffect.softStart()
+        Interval.start(self, *args, **kwargs)        
 
     def privInitialize(self, t):
-        renderParent = None
-        if self.worldRelative:
-            renderParent = render
+        if self.state == CInterval.SInitial:
+            if self.particleEffect:
+                self.particleEffect.clearToInitial()
+            self.currT = 0
+
         if self.particleEffect:
-            self.particleEffect.start(self.parent, renderParent)
-        self.state = CInterval.SStarted
+            for f in self.particleEffect.forceGroupDict.values():
+                f.enable()
+
+        self.state = CInterval.SStarted        
+        self.__step(t-self.currT)
         self.currT = t
 
     def privStep(self, t):
@@ -58,22 +82,16 @@ class ParticleInterval(Interval):
             self.privInitialize(t)
         else:
             self.state = CInterval.SStarted
+            self.__step(t-self.currT)
             self.currT = t
 
+        if self.currT > (self.getDuration() - self.softStopT):
+            if self.particleEffect:
+                self.particleEffect.softStop()
+
     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
+