May 8, 2024

Creating a Topographic Map from a Point Cloud

Written by: Mackenzie Mills


A quality point cloud is a fantastic starting point for a GIS workflow analyzing and modeling the topography of an area. The tools available in Global Mapper Pro allow users to process a raw point cloud to bring meaning to the lidar returns and create many derivative data layers. With all the capabilities of Global Mapper Pro available at your fingertips, a topographic map, or 3D dataset comprehensively modeling natural terrain and manmade structures, can be generated from a single input layer, a point cloud.

An unedited point cloud
The raw point cloud here is visualized by elevation. In this dataset, all points begin unclassified.


A point cloud describes the vegetation, natural features, and manmade objects in a study area. The first step in creating data from a raw point cloud is classification. This process groups the points into defined classes that bring additional meaning to the point cloud data. Once classified, classes of points in the point cloud can be focused on or removed from consideration in the subsequent processes. 

Global Mapper Pro’s Automatic Point Cloud Analysis tool provides built-in class models for some commonly identified point cloud classes: noise, ground, vegetation, buildings, poles, and powerlines. Not all of these classes can or need to be identified in every dataset. For datasets that do, the tool in Global Mapper allows multiple classification routines to be executed with a single click. 

Classified point cloud
Checking the boxes for the classes you would like to identify in the point cloud and then clicking Classify Features prompts Global Mapper Pro to analyze the point cloud and attribute points to all the selected classes.

Moving beyond the basic classes, the geometric segmentation and custom classification functionalities in Global Mapper Pro can be used to identify features in the point cloud and apply additional classifications. In this dataset, geometric segmentation has been used to identify paved surfaces based on curvature and intensity values. A custom class is then applied to the identified ground points representing paved surfaces. Cars and other smaller features on the ground surface are left unclassified, making it easy to filter out these points in Global Mapper Pro.

3D classified point cloud
As the point cloud is classified, a more obvious topographic meaning is brought to the dataset.


The central feature in this area of interest is a shopping center. To better model the building features on this property, vector features can be created from the point cloud using another section of Global Mapper Pro’s Automatic Point Cloud Extraction tool, extraction. Relying on a classified point cloud, the extraction section of the automatic analysis tool creates vector features representing the objects in the point cloud data. Since the point cloud is a 3D dataset, the vector features extracted from it are also 3D.

The custom- classified parking lot area in this dataset can also be extracted using point selection and a digitizer area feature creation option. With many different selection modes, along with the power of the point cloud segmentation tool in Global Mapper Pro, a bounding area can be generated for almost any feature identified in a point cloud.


Since ground has been classified in this dataset, a raster terrain model, also known as a digital elevation model or elevation grid, can be created from only the ground representing points. The Create Elevation Grid tool in Global Mapper Pro provides multiple methods for grid creation as well as an option to filter the points by classification or other characteristics. By filtering to only the ground points and using a binning grid method, a bare-earth terrain model can be created.

Vector building on top of terrain
The generated terrain surface provides a base for the extracted building features to sit on.

Contour Lines

To gain further insight into the shape of the terrain in this area of interest, Global Mapper can be used to generate 3D vector contour lines from the terrain model now present in the workspace. Contour lines provide another layer of topographic information to a viewer of a 2D map. Generated in Global Mapper at the user set interval with vector labeling and styling options, contour lines help to describe the terrain of the area. 


Global Mapper’s Create Elevation Grid tool is a bit misnamed as it holds the capability to generate image layers from other attributes present in a point cloud. If present in a point cloud RGB color values, intensity, classification code, and other attributes can be used to create an image layer for the point cloud area. In this workflow, the source point cloud does not contain RGB color values, but since it has been classified, the point classification codes can be transformed into an image. This gives some additional context to the area.

Topographic lines in a point cloud
Before generating this image from the point cloud, the colors used to display each classification were altered to soften their appearance in the output image.

Creating the Map

All the layers created from the single point cloud layer this workflow began with can be displayed together to create a topographic map. Styling the vector features and ordering the layers in the workspace allows the fine-tuning of the data display for map presentation. Moving to the Map Layout Editor, a tool for creating maps for export to image or print, additional map elements such as a legend, scale bar, and title can be added.

A topographic map
Texture applied from the terrain hill shading to the classification codes image and the display of the contour lines by elevation shader help to convey the topographic information of this area in a 2D map.

With all the power of Global Mapper Pro’s analysis and editing tools, many different types of data can be generated from a single point cloud to generate a topographic map. To try out this workflow and other Global Mapper Pro tools with your data, download a 14-day free trial today!

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