WebGL Pix4d Potree

The system is designed to convert the photo of television towers from the drone into a 3D point cloud to inspect the state of the tower structure


Point cloud converter and inspector

A platform for converting and displaying 3D reconstructions made using conventional photographs taken on a drone and combined into a 3D model. The pix4d program allows you to simultaneously process and combine thousands of photos taken from different angles, and automatically create topographic maps and 3d terrain models.

Information about each photo is recorded in an EXIF ​​file: at what height it was taken, at what angle the camera was rotated, and what data is longitude and latitude. The program uses machine vision and photogrammetry technology to find common points in many photographs.
Every match becomes a key point. If the key point is found in three photographs or more, the program builds this point in space. The more key points, the easier it is to determine the coordinates of a point in space. From here follows the main rule – to maintain a large intersection between photos.
The spatial coordinates of each point are calculated by the method of triangulation: a line of sight or ray is automatically drawn from each survey point to the selected point, and their intersection gives the desired value.
The collection of all 3d points is called a point cloud. In the process of processing photos, an expanded cloud of points is created, which is used to generate a surface composed of triangles (polygons, meshes). The last step is to calculate the resolution (pixel size) and which pixels in the photo correspond to which mesh.