How to find the closest pair of cylindrical faces with a specific radius in Mechanical scripting?

kiran.sai

I have an Ansys Mechanical model with multiple cylindrical faces of 3mm radius distributed across different bodies. I want to write a Python script (in the Mechanical scripting console) that:

1.Finds all faces with a radius of 3mm and group faces who are adjacent
2.Identifies the closest pair of such faces based on centroid distance
3.Creates Named Selections for this pair, like "bpr1" for one set and "bpm1" for its closest set

I've tried iterating over all bodies and faces using DataModel.GetObjectsByType and comparing centroids, but I'm not sure if this is the right approach, or if there's a more efficient built-in method.

kiran.sai

You can follow this script and create named selections for adjacent faces and name them similarly to the closest pair.

I have set a tolerance on the radius in case there is any geometry errors, you can remove that if you want.

import math

target_radius = 3e-03

tolerance = 1e-5

matching_faces = []

for body in DataModel.GetObjectsByType(DataModelObjectCategory.Body):

for face in body.GetGeoBody().Faces:

if abs(face.Radius - target_radius) < tolerance:

matching_faces.append(face)

processed_ids = set()

groups = []

for face in matching_faces:

if face.Id in processed_ids:

continue

sel_info = ExtAPI.SelectionManager.CreateSelectionInfo(SelectionTypeEnum.GeometryEntities)

sel_info.Ids = [face.Id]

ExtAPI.SelectionManager.NewSelection(sel_info)

import toolbar

toolbar.DoGraphicsAdjacentSelect(ExtAPI)

selected_ids = ExtAPI.SelectionManager.CurrentSelection.Ids

fin_ids = []

parent_geo_body = face.Bodies[0]

for fid in selected_ids:

f = None

for candidate in parent_geo_body.Faces:

if candidate.Id == fid and abs(candidate.Radius - target_radius) < tolerance:

f = candidate

break

if f is not None and f.Id not in processed_ids:

fin_ids.append(f.Id)

processed_ids.add(f.Id)

ExtAPI.SelectionManager.ClearSelection()

sel = ExtAPI.SelectionManager.CreateSelectionInfo(SelectionTypeEnum.GeometryEntities)

sel.Ids = fin_ids

ExtAPI.SelectionManager.NewSelection(sel)

final_ids = list(ExtAPI.SelectionManager.CurrentSelection.Ids)

c = face.Centroid

groups.append({'ids': final_ids, 'centroid': c})

ExtAPI.SelectionManager.ClearSelection()

paired = set()

pairs = []

for i in range(len(groups)):

if i in paired:

continue

best_dist = 1e+100

best_j = None

for j in range(len(groups)):

if j == i or j in paired:

continue

c1 = groups[i]['centroid']

c2 = groups[j]['centroid']

dis = math.sqrt((c2[0]-c1[0])**2 + (c2[1]-c1[1])**2 + (c2[2]-c1[2])**2)

if dis < best_dist:

best_dist = dis

best_j = j

if best_j is not None:

paired.add(i)

paired.add(best_j)

pairs.append((groups[i], groups[best_j], best_dist))
model = DataModel.Project.Model
for idx, (g1, g2, dist) in enumerate(pairs):

pair_num = idx + 1