---
title: "FF/FL Define test surface"
slug: "cyclone-3dr-fffl-testsurfacec"
updated: 2026-09-07T11:51:38Z
published: 2026-09-07T11:51:38Z
canonical: "rcdocs.leica-geosystems.com/cyclone-3dr-fffl-testsurfacec"
---

> ## 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.

# FF/FL Define test surface

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

This step helps to define the test surface and the FF/FL values to achieve.

1. Either define a test surface aligned or not to the current UCS (press **SPACE** to change the mode): use the scene to draw it.
2. Define the **Specified Overall Flatness and Levelness** values: that is to say for the test surface and the test sections.
3. Optionally, define **Minimum Local Flatness and Levelness values**: that is to say for each sample line.

> [!WARNING]
> ### Notes
> 
> - The test sections defined in the next step will have to be inside the test surface.
> - In case of a single test section, you can define directly its position in this step.