Aerial Lidar

Menu: Civil / Start / Aerial Lidar

The Aerial LiDAR module enables the visualization, processing, and extraction of information from aerial LiDAR data. It supports LAS and text-based files, allowing users to create surfaces, extract building footprints, and simplify large point clouds. The tools are designed for aerial-classified LiDAR datasets, offering efficient point cloud processing without modifying the original data.

1. Key Features of the Aerial LiDAR Module

✔ Load and visualize aerial LiDAR data
✔ Manage point classifications (e.g., ground, vegetation, buildings)
✔ Extract building footprints automatically
✔ Add points to surfaces with optional simplification
✔ Reduce point cloud density using grid-based and triangulation methods

2. Aerial LiDAR Interface – Options and Descriptions

Loading and Viewing Data

Option	Description
Aerial LiDAR File	Loads LAS or text files. If a text file is used, columns must be specified for coordinate and classification data.
Preview	Opens an independent viewer to display the point cloud before processing.
Bounding Box	Defines a 3D limit for filtering points during visualization and processing. Adjusting this reduces the dataset for faster analysis.

Classification and Data Management

Option	Description
Classification Table	Displays the number of points per class (e.g., ground, vegetation, buildings). Allows filtering by intensity or elevation.
Hide Classes	Uncheck specific classes to remove them from visualization.
Density Bar	Adjusts the number of processed points. Moving to the middle removes 50% of the points for faster performance.

3. Extracting Building Footprints

✔ This tool automatically extracts building rooftops from the point cloud by analyzing the Building class.
✔ Distance and elevation separation values define rooftop breakpoints.
✔ Regularization options control rooftop angles for better structure representation.

🔹 Processing Steps:

Adjust distance & elevation separation values.
Enable regularization options for roof angle smoothing.
Click "Extract" to process the point cloud.
Preview results, then export to DXF/CSV or add to a surface.

4. Adding Points to a Surface

✔ Imports LiDAR points into an existing surface, with or without simplification.
✔ If the surface has an outline, only points inside the boundary are imported.
✔ Exclusion zones can be defined using closed breaklines (selected before adding points).

5. Simplification Methods

🔹 Grid-Based Simplification

Analyzes a planimetric grid to reduce the number of points while preserving terrain accuracy.

Option	Description
Grid Size	Defines the tile size for simplification. Larger tiles remove more points.
Elevation Tolerance	Maximum Z-difference within a tile before subdivision occurs.
Isolated Points Tolerance	Discards outlier points that are significantly higher than the tile’s average.
Use Plane	Calculates elevation using an average plane instead of vertical differences.
No. Times	Number of subdivisions before forcing the retention of a single point.

🔹 Triangulation-Based Simplification

✔ Uses surface triangulation to identify and remove insignificant triangles.
✔ Works best for terrain modeling, keeping important elevation variations while removing flat or redundant areas.
✔ If "Simplify by Grid" is also selected, grid simplification is applied first for faster processing.

Option	Description
Slope Tolerance	Minimum slope variation between neighboring triangles for retention.
Elevation Tolerance	Minimum Z-difference required to keep a triangle.
Extract Breaklines	Extracts and simplifies breaklines, applying maximum deviation & variation limits.

6. Best Practices for Aerial LiDAR Processing

✔ Use the bounding box to reduce the dataset size and speed up processing.
✔ Apply classification filters to isolate specific objects (e.g., buildings, vegetation).
✔ Extract building footprints efficiently by adjusting distance and elevation separation settings.
✔ Simplify point clouds using grid or triangulation methods before adding them to surfaces.
✔ Export results to DXF or CSV for integration with GIS and CAD workflows.

🚀 Optimize Aerial LiDAR Processing for Faster & More Accurate Data Extraction!

With automated classification, footprint extraction, and advanced simplification tools, VisionLidar’s Aerial LiDAR module provides a powerful solution for managing large-scale LiDAR datasets in civil engineering, GIS, and infrastructure projects. 🌍📏🏗️

VisionLidarEN