align selected vertices in line #maya #align #script #vertices #mesh

lineIt

import maya.api.OpenMaya as om2
import maya.cmds as mc
import math
import maya.mel as mel 
'''
select two main vertices 
and then select child vertices 
that you need to align
in line between the main ones

all - will align in all axis
x - will align in 'y' and 'z' axis, leaving plane 'x' inactive in alignment
y - will align in 'x' and 'z' axis, leaving plane 'y' inactive in alignment
z - will align in 'x' and 'y' axis, leaving plane 'z' inactive in alignment

make sure you select at least 3 vertices
also note that script skip vertices that has no differences 
in the plane axis 
'''
def lineIt( planeAxis='all'):
	if not mc.selectPref( q=1, trackSelectionOrder=1 ):
		mel.eval('selectPref -trackSelectionOrder true;')
	selVerts = om2.MGlobal.getActiveSelectionList(1)
	dp, comp = selVerts.getComponent(0)
	if comp.isNull():
		mc.warning('Please, select any vertex')
		return
	ids = []
	if selVerts.length() > 2:
		for s in xrange( selVerts.length() ):
			dp, comp = selVerts.getComponent(s)
			compFn = om2.MFnSingleIndexedComponent(comp)
			ids.extend( compFn.getElements() )
		parentVerts = ids[0:2]
		childVerts = ids[2:len(ids)]
		parPoint0 = om2.MVector(mc.xform( '%s.vtx[%i]' %( dp.fullPathName(), parentVerts[0] ) , q=1, ws=1, t=1 ) )
		parPoint1 = om2.MVector(mc.xform( '%s.vtx[%i]' %( dp.fullPathName(), parentVerts[1] ) , q=1, ws=1, t=1 ) )
		objBBoxMin = mc.getAttr( dp.partialPathName() + '.boundingBoxMin' )
		objBBoxMax = mc.getAttr( dp.partialPathName() + '.boundingBoxMax' )
		bBoxMin = [ b1 - 1.0 for b1 in objBBoxMin[0] ]
		bBoxMax = [ b2 + 1.0 for b2 in objBBoxMax[0] ]
		for c in childVerts:
			childPos = mc.xform( '%s.vtx[%i]' %( dp.fullPathName(), c ) , q=1, ws=1, t=1 )
			t0 = t1 = t2 = None
			if planeAxis == 'y':
				if round( childPos[1], 3 ) != round( parPoint0[1], 3 ) or round( childPos[1], 3 ) != round( parPoint1[1], 3 ):
					t0 = om2.MVector( bBoxMin[0], childPos[1], bBoxMin[2] )
					t1 = om2.MVector( bBoxMin[0], childPos[1], bBoxMax[2] )
					t2 = om2.MVector( bBoxMax[0], childPos[1], bBoxMax[2] )
				else: return
			elif planeAxis == 'z':
				if round( childPos[2], 3 ) != round( parPoint0[2], 3 ) or round( childPos[2], 3 ) != round( parPoint1[2], 3 ):
					t0 = om2.MVector( bBoxMin[0], bBoxMin[1], childPos[2] )
					t1 = om2.MVector( bBoxMin[0], bBoxMax[1], childPos[2] )
					t2 = om2.MVector( bBoxMax[0], bBoxMax[1], childPos[2] )
				else: return
			elif planeAxis == 'x':
				if round( childPos[0], 3 ) != round( parPoint0[0], 3 ) or round( childPos[0], 3 ) != round( parPoint1[0], 3 ):
					t0 = om2.MVector( childPos[0], bBoxMin[1], bBoxMin[2] )
					t1 = om2.MVector( childPos[0], bBoxMin[1], bBoxMax[2] )
					t2 = om2.MVector( childPos[0], bBoxMax[1], bBoxMax[2] )
				else: return
			if planeAxis == 'all':
				pVec = parPoint0 - parPoint1
				cVec = om2.MVector( childPos )
				dotp = ( ( parPoint0 - om2.MVector( childPos ) ) * ( pVec ) ) / ( pVec ).length()
				mc.xform( '%s.vtx[%i]' %( dp.fullPathName(), c ) , ws=1, t= ( cVec + ( parPoint0 - cVec ) - dotp * ( pVec ).normal() ) )
			else:	
				if t0 and t1 and t2:
					v1 = t1 - t0
					v2 = t2 - t0
					normal = (v2 ^ v1).normal()
					denom = normal * ( parPoint1 - parPoint0 )
					if denom <= 0.0:
						denom += 0.000001
					intersectPoint = parPoint0 + ( parPoint1 - parPoint0 ) * (( normal * (t0 - om2.MVector(parPoint0))) / denom )
					mc.xform( '%s.vtx[%i]' %( dp.fullPathName(), c ) , ws=1, t=intersectPoint )
lineIt('all')