3D Modeling, Mapping and LiDAR Data Processing

The project was completed in three main stages, each of which was critical for achieving the set objectives. Each stage included several sub-stages that reflect in detail the process and technologies applied by our team to achieve the result.

1. LiDAR Data Classification

In the first stage, our team carried out the preparation and uploading of LiDAR data, which involved several important steps:

• LiDAR Data Preparation
  Before starting the work, it was necessary to check the data quality, clean it from noise and anomalies, and convert it into a format suitable for processing.
• Point Cloud Classification
  After the data preparation, the classification of the point cloud began, categorizing it into key groups such as ground, buildings, trees, power lines, and others. For each category, separate classes were defined, allowing for accurate identification of different elements in the terrain.
• Use of In-House Developed Algorithms
  To speed up the classification process, in-house developed algorithms were used to automate standard operations, reducing the likelihood of errors and accelerating data processing.
• Result Verification and Correction
  After the automatic classification, the results were verified and corrected. Specifically, complex or ambiguous cases were manually reviewed, and the boundaries between different object classes were refined.

We would like to highlight class 16 — Road Vegetation, to which we assigned points representing low vegetation. Often, clients themselves decide whether it is better to assign these points to the road class or leave them in the low vegetation class. To save time, we decided to place them in a separate class, which allows for classification into the appropriate class at any moment, according to the client’s requirements.

2. 3D Building Modeling

The second stage was the creation of 3D building models, which included several important steps:

• Data Preparation for 3D Modeling
  After the classification was completed, the data was prepared for 3D model creation. This involved defining the building outlines, their heights, and accurately separating the buildings from other objects in the terrain, such as trees and roads.
• Creation of 3D Building Models
  The next step was creating precise 3D models of the buildings, which included considering the dimensions, shapes, and heights of each building to ensure their realistic representation in 3D space.
• Quality Checking and Correction of 3D Models
  After the basic models were created, a verification and correction process was carried out, where each model was compared with real data to ensure compliance with exact requirements.

3. 3D Topographic Plan

In the third stage, we focused on creating a 3D topographic plan to ensure proper topological interaction between objects in 3D space. This stage included the following sub-points:

• Creation of the 3D Topographic Plan
  After completing the building modeling, it was important to correctly integrate all objects (buildings, power lines, roads) in the 3D space to analyze their relative positions.
• Verification and Correction of the Topographic Plan
  Once the initial topographic plan was built, verification and correction of the object placement were performed. The relationships between different elements, such as buildings and power lines, were checked. Possible obstacles and planning deficiencies were identified, allowing for corrections to the topographic plan to avoid issues in the future.
• Identification and Resolution of Topology Issues
  In case any topology issues, such as incorrect connections between elements or improperly placed objects, were identified, manual correction and automatic resolution were carried out to achieve high accuracy in the results.

We created the 3D topographic plan according to high-quality standards, which required special attention to detail. Therefore, it was crucial to ensure that all nodes were accurately connected to each other. Working with roofs, in particular, was challenging, as we had to carefully control the precision of the connections to avoid errors in the modeling process.

In addition, as part of this project, we also raised the conventional symbols that usually represent the height of objects on the ground (such as manholes, hydrants, etc.) into 3D space. This allowed us to accurately represent the height of each object above the ground level, which was crucial for the precise placement of all elements in the 3D topographic plan and ensured flawless topological interaction between them.

Also, we provided another methodology for the LiDAR classification. Please check this case here.