Maya Create Bone at Custom Pivot

When rigging weapons or hard surface meshes with specific angles or orientations, I want to be able to quickly create a bone with the same orient of a selected mesh component. I want to ensure I have as precise a position and orientation as possible.

With the latest versions of Maya creating and manipulating pivots have become far easier with native tools. Though, I've yet to see a process to do exactly what I've been looking for. I've written a fairly simple script to achieve what I've found to be the most intuitive approach to creating a bone with the position and orientation that I desire.

Here is a brief walk through of how I create bones using a custom pivot. The script I use can be found below.
    
Character Model by Chris Wells

	import maya.cmds as cmds
	import pymel.core as pymel
	def create_pivot_bone():
	"""
	Create a bone from the customPivot context
	In component mode of a mesh:
	Press "D" or "Insert" to go into custom pivot context
	If you click on edges verts or faces the pivot will auto align
	If you want to aim an axis click on the axis and Ctrl+Shift on another vert/edge/face to aim it
	When you have the pivot you want run this to create the joint with that pivot
	*Arguments:*
	* ``None``
	*Keyword Arguments:*
	* ``None``
	*Returns:*
	* ``None``
	*Author:*
	* randall.hess, randall.hess@gmail.com, 9/3/2017 5:17:19 PM
	"""
	# get these values
	loc_xform = None
	loc_rp = None
	# Get manipulator pos and orient
	manip_pin = cmds.manipPivot(pinPivot=True)
	manip_pos = cmds.manipPivot(q=True, p=True)[0]
	manip_rot = cmds.manipPivot(q=True, o=True)[0]
	# delete existing temp objs
	temp_joint = None
	temp_loc = None
	temp_cluster= None
	temp_joint_name = 'temp_joint'
	temp_loc_name = 'temp_loc'
	temp_cluster_name = 'temp_cluster'
	temp_objs = [temp_joint_name, temp_loc_name]
	# get the selectMode
	sel_mode_obj = cmds.selectMode(q=True, o=True)
	sel_mode_component = cmds.selectMode(q=True, co=True)
	# store and clear selection
	selection = cmds.ls(sl=True)
	py_selection = pymel.ls(sl=True)
	if len(selection) == 0:
	cmds.warning('You must have a selection!')
	return
	if len(selection) > 0:
	sel = selection[0]
	py_sel = py_selection[0]
	# create temp joint and set pos/rot
	cmds.select(cl=True)
	temp_joint= pymel.joint(n=temp_joint_name)
	temp_loc = pymel.spaceLocator(n=temp_loc_name)
	# get transform from the selected object
	if type(py_sel) == pymel.nodetypes.Transform:
	# snap loc to position
	const = pymel.pointConstraint(sel, temp_loc, mo=False, w=1.0)
	pymel.delete(const)
	const = pymel.orientConstraint(sel, temp_loc, mo=False, w=1.0)
	pymel.delete(const)
	else:
	# get transform from parent object
	if type(py_sel.node()) == pymel.nodetypes.Mesh:
	parent = py_sel.node().getParent()
	if parent:
	const = pymel.pointConstraint(parent, temp_loc, mo=False, w=1.0)
	pymel.delete(const)
	const = pymel.orientConstraint(parent, temp_loc, mo=False, w=1.0)
	pymel.delete(const)
	# get the transforms
	loc_xform = pymel.xform(temp_loc, q=True, m=True, ws=True)
	loc_rp = pymel.xform(temp_loc, q=True, ws=True, rp=True)
	# rotate the temp_loc if manip rot has been modified
	if not manip_rot == (0.0,0.0,0.0):
	pymel.rotate(temp_loc, manip_rot)
	# move position to the cluster position
	if not manip_pos == (0.0,0.0,0.0):
	pymel.xform(temp_loc, ws=True, t=manip_pos)
	# get the transforms
	loc_xform = pymel.xform(temp_loc, q=True, m=True, ws=True)
	loc_rp = pymel.xform(temp_loc, q=True, ws=True, rp=True)
	# get the position from the component selection
	if not type(py_sel) == pymel.nodetypes.Transform:
	cmds.select(selection, r=True)
	cmds.ConvertSelectionToVertices()
	try:
	cluster = cmds.cluster(n=temp_cluster_name)[1]
	except:
	cmds.warning('You must select a mesh object!')
	pymel.delete(temp_joint)
	pymel.delete(temp_loc)
	return
	# get the cluster position
	cmds.select(cl=True)
	pos = cmds.xform(cluster, q=True, ws=True, rp=True)
	# snap to the cluster
	const = pymel.pointConstraint(cluster, temp_loc, mo=False, w=1.0)
	pymel.delete(const)
	cmds.delete(cluster)
	# rotate the temp_loc if manip rot has been modified
	if not manip_rot == (0.0,0.0,0.0):
	pymel.rotate(temp_loc, manip_rot)
	# move position to the cluster position
	if not manip_pos == (0.0,0.0,0.0):
	pymel.xform(temp_loc, ws=True, t=manip_pos)
	# get the transforms
	loc_xform = pymel.xform(temp_loc, q=True, m=True, ws=True)
	loc_rp = pymel.xform(temp_loc, q=True, ws=True, rp=True)
	# remove temp loc
	pymel.delete(temp_loc)
	# modify the joint and stu
	if temp_joint:
	if loc_xform and loc_rp:
	pymel.xform(temp_joint, m=loc_xform, ws=True)
	pymel.xform(temp_joint, piv=loc_rp, ws=True)
	# freeze orient
	pymel.select(temp_joint)
	pymel.makeIdentity( apply=True, translate=True, rotate=True, scale=True, n=False )
	# unpin pivot
	cmds.manipPivot(pinPivot=False)

view raw create_pivot_bone.py hosted with ❤ by GitHub