---
title: "Basic Tutorial | Reconstruct perfect holes on a mechanical part"
slug: "cyclone-3dr-ex-reconstruct-perfect-holes-on-a-mechanical-part"
updated: 2026-09-07T11:51:19Z
published: 2026-09-07T11:51:19Z
canonical: "rcdocs.leica-geosystems.com/cyclone-3dr-ex-reconstruct-perfect-holes-on-a-mechanical-part"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://rcdocs.leica-geosystems.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Basic Tutorial | Reconstruct perfect holes on a mechanical part

In the software, there is a dedicated command for automatically fitting mesh borders with polylines in order to have perfect borders/holes.

> [!TIP]
> Open the file **MeshImproveBorders.3dr** ([download](https://www.cyclone3dr.com/download_helper.php?File=Cyclone3DRSampleData/MeshImproveBorders.3dr)).

In this file, there are a mesh and 5 polylines corresponding to 5 holes. They have been obtained thanks to features extraction (see example in [Exercise: Compute best shapes from clouds and polylines](/v1/docs/cyclone-3dr-ex-compute-best-shapes-from-clouds-and-polylines)) and polylines improvement (see section [Edit polylines](/v1/docs/cyclone-3dr-manage-polylines)).

Select the mesh and the 5 polylines and go to [Define Borders](/v1/docs/cyclone-3dr-setbordersc). There is only one parameter to set: the **Cleaning Distance**. It is the width of the mesh that will be modified in order to fit to the new border. To define this parameter you can:

- Enter directly a value
- Click the button in text field to click two points and then enter two points in order to define the distance

Enter 7 mm or more and click on **Preview**. The result is bad because some or all holes have not been reconstructed due to a too high value, as we can see in the results.

Enter now 1.5 mm then click on **Preview** again. The result is now perfect like in the following picture. You can click **OK** to validate.

![image2019-9-17_10-29-10.png](https://cdn.document360.io/820e11db-8ed5-45ae-ac86-f6b77dcb2aa7/Images/Documentation/image2019-9-17-10-29-10.png)

Borders have been improved in only one click