如何使用 Maya Python API 2.0 在网格中添加边缘

Question

我使用 maya.api.OpenMaya.MFnMesh.subdivideEdges() 函数。边被顶点分割，但相应的新边不会到来。如何在分割边缘上添加边缘？或者如何创建从一个顶点到另一个顶点的边。使用 Maya Python API 2.0 ？

#这是我的 Maya Python API 2.0 代码

import maya.api.OpenMaya as om
verticePos      = [(-0.5, -0.5, 0.5, 1), (0.5, -0.5, 0.5, 1), (-0.5, 0.910894, 0.5, 1), (0.5, 0.910894, 0.5, 1), (-0.5, 0.910894, -0.383361, 1), (0.5, 0.910894, -0.383361, 1), (-0.5, -0.5, -0.383361, 1), (0.5, -0.5, -0.383361, 1), -0.5, -0.5, 1.06715, 1), (0.5, -0.5, 1.06715, 1), (0.5, 0.910894, 1.06715, 1), (-0.5, 0.910894, 1.06715, 1), (-0.5, -1.12433, -0.383361, 1), (0.5, -1.12433, -0.383361, 1), (0.5, -1.12433, 0.5, 1), (-0.5, -1.12433, 0.5, 1), (0, 0.910894, 1.06715, 1), (0, 0.910894, 0.5, 1), (0, 0.910894, -0.383361, 1), (0, -0.5, -0.383361, 1), (0, -1.12433, -0.383361, 1), (0, -1.12433, 0.5, 1), (0, -0.5, 0.5, 1), (0, -0.5, 1.06715, 1)]

polygonCounts   = [4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4]
polygonConnects = [8, 23, 16, 11, 2, 17, 18, 4, 4, 18, 19, 6, 12, 20, 21, 15, 1, 7, 5, 3, 6, 0, 2, 4, 0, 22, 23, 8, 1, 3, 10, 9, 17, 2, 11, 16, 2, 0, 8, 11, 6, 19, 20, 12, 7, 1, 14, 13, 22, 0, 15, 21, 0, 6, 12, 15, 3, 17, 16, 10, 18, 17, 3, 5, 19, 18, 5, 7, 20, 19, 7, 13, 21, 20, 13, 14, 1, 22, 21, 14, 23, 22, 1, 9, 16, 23, 9, 10]

uValues         = [0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625]
vValues         = [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]

#Convert to MPointArray
vertices        = om.MPointArray ()
for eachPos in verticePos :            
    mPoint      = om.MPoint ()            
    mPoint.x    = eachPos[0]      
    mPoint.y    = eachPos[1]      
    mPoint.z    = eachPos[2]              
    vertices.append (mPoint)

mfnMesh    = om.MFnMesh ()
mfnMesh.create(vertices, polygonCounts, polygonConnects, uValues, vValues)
mfnMesh.updateSurface ()
cmds.sets (mfnMesh.fullPathName(), e=1, fe='initialShadingGroup')
mfnMesh.updateSurface()

#Spliting Edges################################
edgeIDs     = [5,7,19,14,12,32,15,17]
mfnMesh.subdivideEdges (edgeIDs, 1)

Answer 1

使用 OpenMaya.MFnMesh.split()。 MFnMesh.split，需要的信息：

[in]    placements  array that contains elements of the SplitPlacement enumeration. They represent where to place the new vertices for the split.
[in]    edgeList    array of edge IDs to be split, in order of their appearance in the split. There must be as many elements in this array as there are SplitPlacement::kOnEdge elements in the placements array.
[in]    edgeFactors     array of factors in the range [0,1] that represent how far along each edge must the split be done. This array must have the same number of elements as the edgeList array.
[in]    internalPoints  array of positions for the vertices that will be added inside existing faces. There must be as many elements in this array as there are SplitPlacement::kInternalPoint elements in the placements array. This array can be empty. Internal points should be specified on the face between the previous edge id and the next edge id.

工作示例：在此处检查拆分方法：Github，属性收集和干净拆分的准确方法。

import maya.api.OpenMaya as om
verticePos      = [(-0.5, -0.5, 0.5, 1), (0.5, -0.5, 0.5, 1), (-0.5, 0.910894, 0.5, 1), (0.5, 0.910894, 0.5, 1), (-0.5, 0.910894, -0.383361, 1), (0.5, 0.910894, -0.383361, 1), (-0.5, -0.5, -0.383361, 1), (0.5, -0.5, -0.383361, 1), -0.5, -0.5, 1.06715, 1), (0.5, -0.5, 1.06715, 1), (0.5, 0.910894, 1.06715, 1), (-0.5, 0.910894, 1.06715, 1), (-0.5, -1.12433, -0.383361, 1), (0.5, -1.12433, -0.383361, 1), (0.5, -1.12433, 0.5, 1), (-0.5, -1.12433, 0.5, 1), (0, 0.910894, 1.06715, 1), (0, 0.910894, 0.5, 1), (0, 0.910894, -0.383361, 1), (0, -0.5, -0.383361, 1), (0, -1.12433, -0.383361, 1), (0, -1.12433, 0.5, 1), (0, -0.5, 0.5, 1), (0, -0.5, 1.06715, 1)]

polygonCounts   = [4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4]
polygonConnects = [8, 23, 16, 11, 2, 17, 18, 4, 4, 18, 19, 6, 12, 20, 21, 15, 1, 7, 5, 3, 6, 0, 2, 4, 0, 22, 23, 8, 1, 3, 10, 9, 17, 2, 11, 16, 2, 0, 8, 11, 6, 19, 20, 12, 7, 1, 14, 13, 22, 0, 15, 21, 0, 6, 12, 15, 3, 17, 16, 10, 18, 17, 3, 5, 19, 18, 5, 7, 20, 19, 7, 13, 21, 20, 13, 14, 1, 22, 21, 14, 23, 22, 1, 9, 16, 23, 9, 10]

uValues         = [0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625, 0.625]
vValues         = [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]

#Convert to MPointArray
vertices        = om.MPointArray ()
for eachPos in verticePos :            
    mPoint      = om.MPoint ()            
    mPoint.x    = eachPos[0]      
    mPoint.y    = eachPos[1]      
    mPoint.z    = eachPos[2]              
    vertices.append (mPoint)

mfnMesh    = om.MFnMesh ()
mfnMesh.create(vertices, polygonCounts, polygonConnects, uValues, vValues)
mfnMesh.updateSurface ()
cmds.sets (mfnMesh.fullPathName(), e=1, fe='initialShadingGroup')
mfnMesh.updateSurface()

# OpenMaya.MFnMesh.subdivideEdges() dividing the selected 
# edges(we will get new Vertices/Edges)
# The real challenge is connect the new vertices with each other, in order....
# my solution is hacking the right info and connect the Vertices,
# its based on the correct edge flow/selection...

#find all connected edges per Vertex
def ver_coll(rr):
  dict = {}
  for vertexid in range(rr):
    vIdArray = om1.MIntArray()
    vIdArray.append(vertexid)
    vtxCom = om1.MFnSingleIndexedComponent()
    vtxCom.create(om1.MFn.kMeshVertComponent)
    vtxCom.addElements(vIdArray)
    sel = om1.MSelectionList()
    sel.clear()
    sel.add(mfnMesh.fullPathName())
    meshdag = om1.MDagPath()
    sel.getDagPath(0,meshdag)
    vtxIter = om1.MItMeshVertex(meshdag,vtxCom.object())
    vtxIter.getConnectedEdges(vIdArray)
    util = om1.MScriptUtil(vIdArray)
    data = util.asIntPtr()
    numCE = vIdArray.length()
    dict[vertexid] = [util.getIntArrayItem(data, i) for i in range(numCE)]
  return dict

pre = ver_coll(cmds.polyEvaluate(mfnMesh.fullPathName(), v=True))
edgeIDs = [0, 21, 13, 11, 9, 6, 4, 2] # or [5,7,19,14,12,32,15,17] 
mfnMesh.subdivideEdges(edgeIDs, 1)
post = ver_coll(cmds.polyEvaluate(mfnMesh.fullPathName(), v=True))

object_id = mfnMesh.fullPathName().split("|")[1]

for e in range(0,len(edgeIDs),1):
  con = edgeIDs[e:e+2]
  vtx_ids = []
  for c in con:
    for v in set(post.keys())-set(pre.keys()):
      if c in post[v]:
        vtx_ids.append(v)
  if len(vtx_ids) == 2:
    print vtx_ids 
    cmds.polyConnectComponents("{0}.vtx[{1}]".format(object_id, vtx_ids[0]), "{0}.vtx[{1}]".format(object_id, vtx_ids[1]), adjustEdgeFlow=True, ch=True)
  else:
    vtx = []
    for i in [edgeIDs[0], con[0]]:
      for v in set(post.keys())-set(pre.keys()):
        if i in post[v]:
          vtx.append(v)
    cmds.polyConnectComponents("{0}.vtx[{1}]".format(object_id, vtx[0]), "{0}.vtx[{1}]".format(object_id, vtx[1]), adjustEdgeFlow=True, ch=True)