How to make a real 3D model

Jul 05, 2023

The production of real-world 3D models starts with data collection. The realism of the model lies in the same color as the real world, which is derived from the imagery taken from the sky. At present, oblique photogrammetry technology is mainly used for aerial photography. By carrying multiple sensors on the same flight platform, images can be collected from different angles such as vertical and oblique at the same time, and more complete and accurate information on ground objects can be obtained. After the image is acquired, it is necessary to process the two-dimensional image into a three-dimensional model of the real scene through the technical means of photogrammetry. Photogrammetry is a technology that performs image matching based on the same-named points in the overlap between adjacent images, and obtains the disparity and depth information between adjacent images. Combining the position and attitude information of each image, the spatial relationship between adjacent images is calculated using photogrammetry technology. Based on these relationships, the pixels in the image are discretized in the three-dimensional space through dense image matching, and become discrete colored points in the three-dimensional space, which is called "color point cloud".

Colored point cloud not only has the geometric characteristics of point cloud, but also has color information. Through the triangular network construction 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".

Finally, the color attributes of the color point cloud are mapped to the surface of the white mold according to the spatial position of the point cloud, so that a real-world 3D model with both geometric appearance and real color texture is completed.