---
title: "Constraint Mesh"
slug: "cyclone-3dr-constraintmeshc"
updated: 2026-09-07T11:51:46Z
published: 2026-09-07T11:51:46Z
canonical: "rcdocs.leica-geosystems.com/cyclone-3dr-constraintmeshc"
---

> ## 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.

# Constraint Mesh

![CmdConstraintMesh.svg](https://cdn.document360.io/820e11db-8ed5-45ae-ac86-f6b77dcb2aa7/Images/Documentation/CmdConstraintMesh.svg)

This command creates or modifies a mesh according to one or more polylines.

If you select:

- point cloud(s), it will be meshed with constraints.
- mesh, constraints will be added to the mesh.
- only polylines and sets of polylines, it will create a mesh with polylines as constraints.

The constraint is a polyline, and it means that no triangle is allowed to cross the polyline.

> [!TIP]
> ### Requirements
> 
> Select point cloud(s) and polyline(s) or a mesh and polyline(s) or polyline(s) only and launch the command.

1. The option **2D Computation** is available only if your selection contains a mesh.
  - If unchecked, we use the mesh properties to determine the best direction.
  - If checked, define a [Meshing direction](/v1/docs/cyclone-3dr-definenormaldirection).
2. The option **Deviation** is available only if your selection contains a point cloud. It is the 3D deviation error used during calculation (accuracy). A low value allows the meshing of small details but will be very time consuming and creates a very heavy mesh and an aberrant (or noisy) result.
3. The option **Keep all points** is available only if your selection contains a point cloud. If checked, it will use all points to create the mesh.
4. Choose the type of result with **Cut in parts** option:
  - If checked, the resulting mesh is cut out into pieces to follow the polylines.
  - If unchecked, after meshing, the pieces inside closed polylines are kept.

> [!TIP]
> ### Tip & Trick
> 
> If you want to **Cut in parts**, the polyline must be closed or use a polyline crossing the mesh in order to have disctinct parts.