Steps for making real-world 3D models

May 18, 2023

The real scene 3D constructs the real scene 3D model through oblique photography, and puts the real scene 3D model into the GIS platform for application. It is the 3D model result of oblique photography technology, because the texture pasted on the 3D model is a realistic texture, so it is a real 3D model.

Step 1： UAV image acquisition

The realism of the real-world 3D model comes from its realistic and intuitive texture, and the same color as reality comes from the images taken by drones in the air. The production of real-world 3D models starts with data collection.

Step 2: Photogrammetry

Calculate the adjacent images through photogrammetry to obtain spatial three-dimensional distance information. Combining the position and attitude information of each image, the spatial relationship between adjacent images is calculated using photogrammetry technology.

Figure1:Schematic Diagram Of The Overlapping Relationship Between Adjacent Images

Step 3: Colored point cloud

Based on these relationships, each pixel in the image is discretized in three-dimensional space through image dense matching, and becomes a discrete colored point in three-dimensional space, which is called "color point cloud".

Figure2:Color Point Cloud 

The color point cloud not only has the geometric characteristics as a point cloud, but also has color information for each point. Through the TIN triangulation network method, the discrete point cloud points are connected to form a triangular patch and a triangular network, which is used as the basic model in the real 3D model - "white model".

According to the spatial position of the point cloud, the color information of the point cloud is mapped to the surface of the white mold. In this way, the realistic 3D model with both geometric appearance and realistic color texture is completed!

Figure3:The effect of real scene 3D model