---
title: "Basic Tutorial | Create planar sections of a mesh (extract contour lines)"
slug: "cyclone-3dr-ex-create-planar-sections-on-a-mesh-extr-contour"
updated: 2026-09-07T11:51:23Z
published: 2026-09-07T11:51:23Z
canonical: "rcdocs.leica-geosystems.com/cyclone-3dr-ex-create-planar-sections-on-a-mesh-extr-contour"
---

> ## 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 | Create planar sections of a mesh (extract contour lines)

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

It contains the mesh of a mountain, and we want to create contour lines on it. Select the mesh and go to [Planar Sections](/v1/docs/cyclone-3dr-planarsectionc). This command allows to compute one or more sections, all in parallel planes, defined by a given direction.

Here we are going to compute sections of the mesh with a regular step along the direction of the Z axis, so:

- Enter Z for axis direction.
- Choose the option Regular.
- Set the Step to 50 m in order to have a section each 50 meters of the whole mesh.
- Set the Range to All over.

When you press **Preview** a result window appears to inform you that 37 polylines have been extracted. You can hide the planes.

Click **OK, Exit**. All the polylines are inserted in a new folder called **Planar Sections**. Each polyline is named with its Z value.

![a9c94425-a919-405b-9e8c-23db521808ae.png](https://cdn.document360.io/820e11db-8ed5-45ae-ac86-f6b77dcb2aa7/Images/Documentation/a9c94425-a919-405b-9e8c-23db521808ae.png)

Create contour lines