Separate Faces Into Objects Along Mesh Height

iterative_polyseparate.py

### iterative_polyseparate.py
### author: Kelly Yu

import maya.cmds as cmds

cmds.select(clear=True)
# select a list of objects starting with 'bunny' and get the first element
bunny = cmds.ls('bunny')[0]
# retrieve face count
bunny_face_count = cmds.polyEvaluate(bunny, face=True)

slices_map = {}
for i in xrange(bunny_face_count):
    # get something like bunny.f[333]    
    face_name = bunny + '.f[%d]' % i
    # select the specific face
    cmds.select(face_name, replace=True)
    # find the bounding box info of this face, specifically where it lies on the y axis
    ((_,_), (ymin,ymax), (_,_)) = cmds.polyEvaluate(face_name, boundingBoxComponent=True)
    # assign a slice number
    slice_number = int(ymax/0.135 + 1)
    # init the list in the dict if necessary
    if slice_number not in slices_map:
        slices_map[slice_number] = []
    # add the face to the right slice    
    slices_map[slice_number].append(face_name)

for slice in slices_map.keys():
    # select all the faces in this slice
    cmds.select(slices_map[slice], replace=True)
    
    ### psuedocode starts here ###
    # separate faces from bunny mesh
    name_of_separated_mesh, name_of_remaining_mesh = cmds.polySeparate(useSelected=True)
    # rename the remaining mesh to be the original name (bunny) so the keys in slices_map still work
    cmds.select(name_of_remaining_mesh, replace=True)
    cmds.rename('bunny', useSelected=True)