Well modeling chains can be tedious, so here we go, a small script that creates a chained link for a provided curve
'''
Linked Chain
Creates a Torus like object, links them together as linked Chain and positions the chain along a curve
Example:
1. Select a curve in Maya
2. Execute command:
Poly_Linked_Chain(radius = 1, sectionradius =0.1, extrude = 1, variation = 20, name="chain").createChainForSelectedCurve()
Created on May 7, 2013
@author: Neal Buerger www.nealbuerger.com
'''
import pymel.core as pm
import random
class Poly_Linked_Chain:
def __init__(self, **kwargs):
"""
Accepts following Keywords:
radius: of the Torus created (Default 1)
sectionradius: of the Torus (Default 0.1)
extrude: length of the torus extrusion (Default 0)
variation: along the rotation of the linked elements (Default 0)
name: name of the chain (Default chain)
"""
self.radius = kwargs.get("radius" ,1)
self.sectionradius = kwargs.get("sectionradius" ,0.1)
self.extrude = kwargs.get("extrude" ,0)
self.variation = kwargs.get("variation" ,0)
if self.variation < 0:
self.variation = abs(self.variation)
if self.variation > 45:
self.variation = 45
self.name = kwargs.get("name" , "chain")
self.name = self.name + str(len(pm.ls(regex= "%s\d*" % self.name))+1)
def createLink(self):
"""
creates a Torus and extrudes half of it
To be used as alternative to a provided geometry
"""
basechain = pm.polyTorus(radius = self.radius, sr = self.sectionradius, tw= 0, sx = 20, sy = 20, ax = (0,1,0), ch = 1)[0]
if self.extrude is not 0:
faces = []
for j in basechain.vtx:
if j.getPosition()[0] > 0:
faces.append(j.connectedFaces())
pm.polyExtrudeFacet(faces, translateX=self.extrude)
return basechain
def makeChain(self, obj, linklenght, chainlenght, preserveObj = False):
"""
Uses provided geometry to create a straight chain
obj: object to be used for the chain
linklenght: lenght of the obj
chainlenght: number of links that are created
"""
if preserveObj:
obj = pm.duplicate(obj, un=True)[0]
pm.move(obj, 0,0,0)
chain = [obj]
rotValue = 0
for i in range(1, chainlenght):
obj = pm.duplicate(chain[0])[0]
rotValue += 90 + random.randint(-self.variation, self.variation)
if rotValue >= 360:
rotValue -= 360
pm.rotate(obj, [rotValue, 0, 0])
distance = linklenght * i
pm.move(obj, distance,0,0)
chain.append(obj)
return chain
def rigChain(self, chain):
"""
takes chain and adds joints and a smooth bind to rig it
chain: list of objects
"""
pm.select(deselect = True)
jnts = []
for obj in chain:
pos = obj.translateX.get(), obj.translateY.get(), obj.translateZ.get()
jnt = pm.joint(p = pos)
jnts.append(jnt)
pm.rename(jnt, self.name + "_joint%d" % len(jnts))
linked = pm.polyUnite(chain, ch = 0)[0]
self.name = pm.rename(linked, self.name)
pm.skinCluster(linked, jnts[0])
return jnts
def addClusterHandles(self, crv):
"""
Adds Cluster Handles to Curve for every cv
"""
for i in crv.cv:
pm.parent(pm.cluster(i), crv)
def createChainForCurve(self, crv, obj = None, linklenght = 1):
"""
Uses the Curve and creates a chain based on the object that is passed into the function
crv = curve to be used
obj = object to be used
linklength = lenght of the obj
"""
if obj is None:
obj = self.createLink()
linklenght = (2*(self.radius - self.sectionradius*2)+self.extrude)
chainlenght = int(pm.PyNode(crv).length()/linklenght)
chain = self.makeChain(obj = obj, linklenght = linklenght, chainlenght = chainlenght)
jnts = self.rigChain(chain)
ik = pm.ikHandle( startJoint=jnts[0], endEffector=jnts[-1], solver='ikSplineSolver', createCurve=False, curve=crv)[0]
pm.rename(ik, self.name + "_ikHandle")
ctrlgrp = pm.group(jnts[0], ik, n = "%sctrl_grp" % self.name)
ctrlgrp.v.set(False)
pm.group(crv, self.name, ctrlgrp, n = "%s_grp" % self.name)
self.addClusterHandles(crv)
pm.select(deselect = True)
return self.name
def createChainForSelectedCurve(self):
"""
Creates Chains for selected curves
"""
return [self.createChainForCurve(i) for i in pm.ls(sl =True, tr=True) if pm.nodeType(i.getShape()) == "nurbsCurve"]
def deleteRig(self, name):
"""
Removes Rig from geometry
name: name of geometry
"""
parent = pm.PyNode(name).getParent()
pm.delete(name, ch = True)
pm.parent(name, w = True)
pm.delete(parent)
