If we have a file with face centroid locations, how can we automatically get the nearest vertex?

Erik Kostson

Say we have a text file (called: vercentroids.txt) containing centroid locations (x,y,z coordinates) for different faces. We also have a face named selection that appears first on the Named selection tree. How can we automatically get the vertex nearest these centroid locations?

Erik Kostson

Below is a sample script showing one way of doing this. In summary it will read in the vercentroids text file, and loop through all faces in the first named selection and their vertices, trying to get the one closest to the centroid. Finally it will create a named selection containing the nearest vertices. As bonus it will create a stress result for each vertex.

import csv
cx=[]
cy=[]
cz=[]
myv=[]
myvIds=[]
dist=1E12
with open("D:/vercentroids.txt", 'rb') as f: # change file as needed
    reader = csv.reader(f)
    for row in reader:
        cx.append(row[0])
        cy.append(row[1])
        cz.append(row[2])
model = ExtAPI.DataModel.Project.Model
analysis=model.Analyses[0]
solution=analysis.Solution
ns=model.NamedSelections.Children[0]
for j in range(0,len(cx)):
    nId=ns.Location.Ids
    for face in nId:
        f = ExtAPI.DataModel.GeoData.GeoEntityById(face)
        vertices=f.Vertices
        for ver in vertices:
            vsx=ver.X
            vsy=ver.Y
            vsz=ver.Z
            dists=sqrt((float(cx[j])-vsx)**2+(float(cy[j])-vsy)**2+(float(cz[j])-vsz)**2)
            if dists<dist:
                myvs=(ver)
                dist=dists
    dist=1E12
    myv.append(myvs)
    myvIds.append(myvs.Id)
with Transaction():
    for i in range(0,len(myvIds)):
        selection = ExtAPI.SelectionManager.CreateSelectionInfo(SelectionTypeEnum.GeometryEntities)
        selection.Ids=[myvIds[i]]
        newns=ExtAPI.DataModel.Project.Model.AddNamedSelection()
        newns.Location=selection
        r=solution.AddEquivalentStress()
        r.Location=newns