w07 - recap and scripts

On our 7th class, we looked into some vector math to help us with certain calculations in Maya. We then developed the following functions:

#######
##
## VECTOR FUNCTIONS
##

import maya.cmds as cmds
import math

#find the magnitude (length) of a vector
def magnitude(v):
	#v is a list of x,y,z values
	x = v[0]
	y = v[1]
	z = v[2]
	m = math.sqrt( (x*x) + (y*y) + (z*z)  )
	
	return m

#find the distance between two points
#by getting the vector between the points and 
#getting its magnitude
def distance(p1, p2):
	#subtract both vectors
	x1 = p1[0]
	y1 = p1[1]
	z1 = p1[2]
	x2 = p2[0]
	y2 = p2[1]
	z2 = p2[2]
	x = x1 - x2
	y = y1 - y2
	z = z1 - z2
	m = magnitude([x,y,z])
	return m

#find the unit vector of a given vector
def unit(v):
	"returns unit vector of v"
	#firt get magnitude
	m = magnitude(v)
	x = v[0]
	y = v[1]
	z = v[2]
	#divide each element by magnitude
	x = x/m
	y = y/m
	z = z/m
	vu = [x,y,z]
	return vu

#find the new position of an object which
#it supposed to move a certain amount in the
#direction of a vector (which should be a unit vector)
def move(v, amount):
	"Move by certain amount in direction v"
	x = v[0]
	y = v[1]
	z = v[2]
	x = x + amount
	y = y + amount
	z = z + amount
	newP = [x,y,z]
	return newP

#find the vector between two given points
def vectorBetweenPoints(p1, p2):
	"Returns vector between p1 and p2"
	#subtract both vectors
	x1 = p1[0]
	y1 = p1[1]
	z1 = p1[2]
	x2 = p2[0]
	y2 = p2[1]
	z2 = p2[2]
	x = x1 - x2
	y = y1 - y2
	z = z1 - z2
	newV = [x,y,z]
	return newV

We then used a bit of this content to extrude the faces of a certain polygonal object according to its distance to a certain locator, by using the function below:

def extrudeToLocator():
	"Extrude based on distance to a certain locator"
	#get selected poly
	#get selected locator
	#get faces of poly
	#loop through faces
	#	find center
	#	get distance from center to locator
	#	extrude based on distance
	selPoly = cmds.filterExpand(sm=12)
	selLoc = cmds.filterExpand(sm=22)
	
	selPoly = selPoly[0]
	
	allFaces = cmds.ls(selPoly + ".f[:]", fl=1)
	#loop
	for face in allFaces:
		vertex = cmds.polyListComponentConversion( face, fromFace=1, toVertex=1 )
		vertex = cmds.ls(vertex, fl=1)
		#find the center of the face
		xs = 0
		ys = 0
		zs = 0
		#loop through vertices
		for v in vertex:
			pos = cmds.pointPosition(v)
			x = pos[0]
			y = pos[1]
			z = pos[2]
			xs = xs + x
			ys = ys + y
			zs = zs + z
		centerX = xs/len(vertex)
		centerY = ys/len(vertex)
		centerZ = zs/len(vertex)
		#check by placing a locator
		cmds.spaceLocator(p=(centerX, centerY, centerZ))
		
		#find distance to locator
		posLoc = cmds.pointPosition(selLoc)
		d = distance([centerX, centerY, centerZ], posLoc)
		print d
		
		#extrude based on distance
		cmds.polyExtrudeFacet( face, ltz=d)