def addTangentMPTo(startMP, endMP, direction, default=0.5, reverse=False):
'''
add a "tangent" attribute to startLoc, and a tangentLoc to startLoc
at 0, tangentLoc would be exactly on startLoc
at 1, tangentLoc would be projected on direction vector onto endLoc's plane
direction (string): 'x', 'y', or 'z'
reverse (bool): reverse direction
return tangentLoc
'''
# add tangentLoc
tangentLoc = mc.spaceLocator(n=startMP+'_tangent_loc')[0]
rt.parentSnap(tangentLoc, startMP)
# add planeLoc - moves on plane of endMP, to help calculcate max distance
planeLoc = mc.spaceLocator(n=endMP+'_plane_loc')[0]
rt.parentSnap(planeLoc, endMP)
# pointConstraint planeLoc to startMP
# skip "direction" axis, to maintain sliding on endMP's plane
mc.pointConstraint(startMP, planeLoc, skip=direction)
# get distance between startMP and planeLoc
# this is the maximum length for tangent
maxDistance = cn.create_distanceBetween(startMP, planeLoc)
# add "tangent" attribute to startMP
mc.addAttr(startMP, ln='tangent', at='double', min=0, max=1, dv=default, k=True)
# multiply tangent value by maxDistance
tangentDistance = cn.create_multDoubleLinear(startMP+'.tangent', maxDistance)
# reverse the direction if necessary
if reverse:
tangentDistance = cn.create_multDoubleLinear(tangentDistance, -1)
# this will be used to drive the tangentLoc
translatePlug = '%s.t%s' % (tangentLoc, direction)
mc.connectAttr(tangentDistance, translatePlug, f=True)
# connect locators for debug
rt.connectVisibilityToggle((planeLoc, tangentLoc), startMP, 'debugTangentLocs', default=False)
rt.connectVisibilityToggle(tangentLoc, startMP, 'tangentLoc', False)
return tangentLoc
def addProxyGeoToJnt(jnt, geo, child=None):
"""
Parent-snaps geo under jnt
If child=None, uses first child of jnt
Distance between jnt & child drives scaleX (assuming X is downAxis)
"""
geo = mc.duplicate(geo, n=jnt + "_proxy")[0]
rt.parentSnap(geo, jnt)
if not child:
child = mc.listRelatives(jnt, c=True, type="joint")[0]
# get distance between jnt and child
dist = cn.create_distanceBetween(jnt, child)
finalScale = cn.create_multiplyDivide(dist, jnt + ".scaleX", 2)
mc.connectAttr(finalScale, geo + ".sx", f=True)
return geo
def addProxyGeoToJnt(jnt, geo, child=None):
'''
Parent-snaps geo under jnt
If child=None, uses first child of jnt
Distance between jnt & child drives scaleX (assuming X is downAxis)
'''
geo = mc.duplicate(geo, n=jnt+'_proxy')[0]
rt.parentSnap(geo, jnt)
if not child:
child = mc.listRelatives(jnt, c=True, type='joint')[0]
# get distance between jnt and child
dist = cn.create_distanceBetween(jnt, child)
finalScale = cn.create_multiplyDivide(dist, jnt+'.scaleX', 2)
mc.connectAttr(finalScale, geo+'.sx', f=True)
return geo
