""" Edward Dale 2006-1-30 Animation Algorithms Particle System Copyright (c) 2005, Edward Dale All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. * Neither the name of Edward Dale nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. """ from cgkit.all import * from random import * from math import pi,cos from keyframe import * class Particle: """ A single particle in the system. """ def __init__(self): """ Initializes the particle to a bunch of empty values. """ self.pos=vec3() self.vel=vec3() self.size=0 self.lifetime=0 self.initiallifetime=0 class System(Component): """ The particle system, which holds all the particles and animates them over time. """ def __init__(self, fp): """ Creates all the particles and intializes their values. """ Component.__init__(self, name="Particle System", auto_insert=True) self.particles=[] self.pause = False self.shrinking = False self.burst = False self.color = vec3(1,0,0) # Make the slots necessary for animation. self.time_slot = DoubleSlot() self.pos_slot = Vec3Slot() self.addSlot("pos", self.pos_slot) self.addSlot("time", self.time_slot) # Parameters about the generation rate of particles genrate = fp.readline().strip().split() self.avggenrate=int(genrate[0]) self.genratedev=int(genrate[1]) # Parameters about the particle lifetime lifetime=fp.readline().strip().split() self.lifetimeavg=int(lifetime[0]) self.lifetimedev=int(lifetime[1]) # Parameters about the emission cone cone=fp.readline().strip().split() self.coneangle=float(cone[0]) self.coneheight=int(cone[1]) # The number of particles to start out with initialparticles=int(fp.readline().strip()) # Set up slot dependencies getScene().timer().time_slot.connect(self.time_slot) n=NotificationForwarder(self.tick) self.time_slot.addDependent(n) for i in xrange(initialparticles): newpart = Particle() self.initializeParticle(newpart) self.particles.append(newpart) exec slotPropertyCode("pos") exec slotPropertyCode("time") def initializeParticle(self, particle): """ Sets all the random properties of the particle. """ particle.size=uniform(0,1) particle.lifetime=max(1,int(normalvariate(self.lifetimeavg,self.lifetimedev))) particle.initiallifetime=float(particle.lifetime) # Use spherical coordinates to figure out emission cone r=uniform(0,self.coneheight) zen=2*pi*random() az=uniform(0, pi * self.coneangle) spherical=(az,zen,r) cartesian=sphericalToCartesian(spherical) particle.pos=self.pos particle.vel=cartesian def tick(self): """ To be called at each clock tick. Needs to advance particles. """ newparticles=[] drawClear() # Stats that don't change at each iteration drawText(pos=(-74, 120, 0), txt="Color %s"%self.color) drawText(pos=(-82, 120, 0), txt="Pause %s" %self.pause) drawText(pos=(-90, 120, 0), txt="Burst %s" %self.burst) drawText(pos=(-98, 120, 0), txt="Shrinking %s" %self.shrinking) drawText(pos=(-66, -64, 0), txt="%3d Avg. Lifetime"%self.lifetimeavg) drawText(pos=(-74, -64, 0), txt="%3d parts per tick"%self.avggenrate) # If the system isn't paused, birth new particles if (not self.pause and ( (self.burst and not self.particles) or not self.burst)): numbirths=int(normalvariate(self.avggenrate, self.genratedev)) for x in range(numbirths): i = Particle() self.initializeParticle(i) self.particles.append(i) else: numbirths=0 drawText(pos=(-82, -64, 0), txt="%3d New Particles"%numbirths) dead=0 for i in self.particles: i.lifetime -= 1 # Age the particle if i.lifetime <= 0: # The particle is dead, so remove it and record another death #self.particles.remove(i) dead += 1 else: newparticles.append(i) # Advance the particle's position for a in range(3): i.pos[a] += i.vel[a] # Figure out what color and size to use based on age age = i.lifetime/i.initiallifetime if self.shrinking: size = age * i.size else: size = i.size color = age*self.color drawMarker(pos=i.pos,color=color,size=size) # Display some more stats drawText(pos=(-90,-64, 0), txt="%3d Dead Particles"%dead) drawText(pos=(-98,-64, 0), txt="%3d Particles"%len(self.particles)) self.particles=newparticles def sphericalToCartesian(spherical): """ Convert a point from spherical coordinates to cartesian coordinates. http://mathworld.wolfram.com/SphericalCoordinates.html """ x=spherical[2]*cos(spherical[1])*sin(spherical[0]) y=spherical[2]*sin(spherical[1])*sin(spherical[0]) z=spherical[2]*cos(spherical[0]) return vec3(x,y,z)