the last thing i was working on - MAYA

crap.py

# random particle velocity -- (the right way)
 
import maya.cmds as cmds
import random

from maya.OpenMaya import MVector
 
random.seed(1234)
 
 
# setup 
amountOfParticles = 50
r = 10
vr = 4
myList = list()
 
 
 
 
#list particles and delete
# convenience
 
particleList = cmds.ls( 'particleObject*' )
#if there are any, then delete them all
if len(particleList) >= 1: 
    cmds.delete(particleList)
    print ('deleted old particleObject')
else:
    print ('no old particleObjects')
 
 
 
# make all particles and add em
 
for i in range( 0, amountOfParticles):
    
    x = random.uniform(- r, r)
    y = random.uniform(- r, r)
    z = random.uniform(- r, r)
    newPosition = (x,y,z)
    myList.append(newPosition)
    
    
cmds.particle(p=myList,n='particleObject#')
 
 
 
velCExpString = 'float $myRange = %s; float $vx = rand(-$myRange, $myRange); float $vy = rand(-$myRange, $myRange); float $vz = rand(-$myRange, $myRange); particleObject2Shape.velocity = <<$vx, $vy, $vz>>;' %(vr)  
#just a little check to see if im doing it right
print (velCExpString)
#the dynExp iterates through each particle... so you dont have to.
cmds.dynExpression( 'particleObject*Shape', s=velCExpString, c=1 )

#make this global 
def vectorCompHandler (x, y, z):
    print(x)

#use MVector to compare position to get distance
# http://download.autodesk.com/us/maya/2010help/API/class_m_vector.html
# http://www.naughtynathan.co.uk/?p=296

# functions in python
# http://www.tutorialspoint.com/python/python_functions.htm

# some python intro stuff
# http://www.astro.up.pt/~sousasag/Python_For_Astronomers/Python_qr.pdf

# boid stuff
# http://www.vonmammen.org/biocaad/2010/01/demos-2d3d-boids-stigmergy-swarm-grammars/
# https://www.youtube.com/watch?v=bJ58tD2hSWs
# 

runTimeBeforeDynamicsExpression.mel

if (particleObject2Shape.particleId == 0 && (frame%10)==0) { vector $myVector = particleObject2Shape.position; python(vectorCompHandler($myVector.x, $myVector.y, $myVector.z));}

// this doesn't work either because im passing the variables incorrectly (i think?)