slow results with mesh stuff, python API

#1

Hi there,

Ok i got my little script working with the python API. It takes a mesh1 (a neutral body mesh), mesh2 (a different character neutral mesh) and mesh3 (the mesh2 character mesh posed differently).

the script should simply store the vert points from mesh1,mesh2,mesh3. then find the difference between mesh2 and mesh3. then finally add the difference to mesh1.

However i thought with python API things were supposed to be really fast with big meshes. My mesh has around 20,000 verts. and although that is alot, i am currently waiting about a minute for the script to finish.

Can anyone please tell me what im doing wrong, or maybe that is just how long things take with a big mesh. i appreciate a fairly big code sample

thanks alot guys,

here is my code:

import maya.OpenMaya as om
   
def getPoints(geo):
    sel = om.MSelectionList()
    dag = om.MDagPath()
   
    sel.add(geo)
    sel.getDagPath(0,dag)
  
    mesh = om.MFnMesh(dag)
  
    vts=om.MFloatPointArray()
    mesh.getPoints(vts, om.MSpace.kObject)
   
    return mesh,vts

 
def findDiff(scan1_verts, scan2_verts):
    diff_list=om.MFloatPointArray()
    for i in xrange(scan1_verts.length()):    
        p1 = scan1_verts[i]
        p2 = scan2_verts[i] 
        diff_list.append(om.MFloatPoint(p2)-om.MFloatVector(p1))

    return diff_list	

def addDiff(diff_list, target_mesh_verts):
    final_list=om.MFloatPointArray()
    for i in xrange(target_mesh_verts.length()):
        p1 = target_mesh_verts[i]
        p2 = diff_list[i]
        final_list.append(om.MFloatPoint(p1)+om.MFloatVector(p2))

    return final_list

def setPoints(girlMesh, finalPos):	
    for i in xrange(girlMesh.numVertices()):
        girlMesh.setPoints(finalPos,om.MSpace.kObject)


#store the vert positions for each mesh
mFnMeshTarget, target_mesh_verts = getPoints("mesh1")
mFnMesh, scan1_verts = getPoints("mesh2")
mFnMesh2, scan2_verts = getPoints("mesh3")

#find the difference between the verts from the expression scan and neutral scan 
diffList = findDiff(scan1_verts,scan2_verts)

#add the difference to the target mesh 
finalPos = addDiff(diffList, target_mesh_verts)

#set the mesh difference to the target mesh
setPoints(mFnMeshTarget,finalPos)
#2

Maybe this function can be the reason. If I read it correctly then you give it a point array. So let’s say you have 10000 points, you set the whole array 10000 times what means you set 10000x10000 = 100000000 points. But you only need to set it once. But hey, if that it correct setting 100000000 points in one minute is not bad :slight_smile:

def setPoints(girlMesh, finalPos):	
    for i in xrange(girlMesh.numVertices()):
        girlMesh.setPoints(finalPos,om.MSpace.kObject)
#3

yeah your right!. ha so stupid. ye it works in 1 second now, thanks

Sam