Selects all points on object 'enveloped_mesh' which have a weight value for 'deformer' bigger than 'weight_threshold'.

SelectPointsByEnvelopeWeight.py

''' SelectPointsByEnvelope '''
# --------------------------------
#  SelectPointsByEnvelopeWeight
#
#   Selects all points on object 'enveloped_mesh' which have a weight value for
#   'deformer' bigger than 'weight_threshold'.
#    
#   Installation:
#     Put this file into C:/Users/<username>/Autodesk/Softimage_XX/Application/Plugins.
#
#   Usage:
#     Open the Script Editor (Alt+4), set the Script language to Python (either
#     via the drop down directly at the top of the editor or File>Preferences).
#     Enter the following line: 
#       Application.SelectPointsByEnvelopeWeight('enveloped_mesh', 'deformer', threshold)
#     where enveloped_mesh is the name of the mesh to select points on,
#     deformer is the name of the deformer the points should be weighted to,
#     threshold is the weight threshold which needs to be met for the point to be selected (0-100%).
#     Example:
#       Application.SelectPointsByEnvelopeWeight('trooper_body', 'bone_hips', 80)
#
from win32com.client import constants as const

XSI = Application


def XSILoadPlugin(in_reg):
    ''' Registers Plugin and commands. '''
    in_reg.Author = 'Ande'
    in_reg.Name = 'SelectPointsByEnvelopeWeight'
    in_reg.Email = 'schlchtwtrfrnt@gmail.com'
    in_reg.URL = 'http://schlechtwetterfront.github.io/'
    in_reg.Major = 1
    in_reg.Minor = 0

    in_reg.RegisterCommand('SelectPointsByEnvelopeWeight', 'SelectPointsByEnvelopeWeight')
    return True

def XSIUnloadPlugin(in_reg):
    ''' Called on Unload. '''
    return True

def SelectPointsByEnvelopeWeight_Init(in_ctxt):
    '''Set up command and arguments.'''
    command = in_ctxt.Source
    command.Description = ''
    command.ReturnValue = True
    command.Arguments.Add('enveloped_mesh')
    command.Arguments.Add('deformer')
    command.Arguments.Add('weight_threshold', const.siArgumentInput, 80)
    return True

def SelectPointsByEnvelopeWeight_Execute(enveloped_mesh, deformer, weight_threshold):
    '''Select points based on deformer's weights.'''
    enveloped_mesh = XSI.Dictionary.GetObject(enveloped_mesh.encode('utf-8'))
    deformer = XSI.Dictionary.GetObject(deformer.encode('utf-8'))

    envelope = enveloped_mesh.Envelopes(0)
    deformer_index = 0
    for index, envelope_deformer in enumerate(envelope.Deformers):
        if envelope_deformer.Name == deformer.Name:
            print envelope_deformer.Name
            deformer_index = index
            break
    envelope_weights = envelope.Weights.Array[deformer_index]
    XSI.DeselectAll()
    XSI.SelectObj(enveloped_mesh)
    XSI.ActivateVertexSelTool()
    point_indices = []
    for index, point_weight in enumerate(envelope_weights):
        print 'index: {0} || weight: {1}'.format(index, point_weight)
        if point_weight >= weight_threshold:
            point_indices.append(index)
    XSI.SelectGeometryComponents('{0}.pnt[{1}]'.format(enveloped_mesh.FullName, ', '.join([str(index) for index in point_indices])))
    return True