Detailed Explanation of Several Methods for UAV 3D Modeling
Due to its unique high-altitude perspective, drones are widely used in engineering surveying and 3D modeling. Obtaining 3D image data through oblique photography, orthophoto imaging, and other methods has the advantages of high efficiency and precision. Its advantage lies in the ability to restore larger objects on the ground on a larger scale.
Currently, there are three main ways to use drones for 3D modeling: point cloud fusion, stereo surround, and intelligent photography.
1. Point cloud fusion
3D modeling of bridges and roads can be achieved by using drones to tilt and photograph objects to obtain images, and then using other tools to synthesize images and generate 3D models. When collecting field data, due to the perspective of the drone from top to bottom, the bottom of the object is easily obstructed by things when it is high, especially in densely populated areas of buildings, which can cause serious imaging problems and poor high-precision shooting results. To compensate for this deficiency, pilots must pass over the target building to obtain complete image information when operating the aircraft. Combined with the ground 3D laser scanning method, the overall appearance image of the object can achieve high accuracy, which is point cloud fusion technology.
2. Three-dimensional surround
Firstly, connect the mobile end of the multi rotor aircraft and find the location point of the target object on the real map; Then create a polygon at the bottom of the object, with the aim of enveloping the object for vertical photography; Then set the height of the polygon to form a three-dimensional polygon, and then set the heading overlap rate and side overlap rate. At this point, the route can be previewed on the interface, and parameters can be adjusted according to needs to start the flight mission. After the task is completed, the image data can be obtained, and then three-dimensional modeling can be synthesized using third-party tools. The advantage of this method is that the steps are short and easy to operate, and the more images you take, the more details you can obtain.
3. Intelligent photography
Find the position of the target object on the live map, manually fly the drone over the target object and click to start photography. The drone will automatically orbit the target object for photography, and the orbit path and pan tilt angle will be displayed on the map interface. After the photography is completed, a prompt will pop up; Then move the video file to a 3D modeling tool to generate a 3D model. This method is also the simplest and most efficient.
In summary, point cloud fusion is more suitable for large-scale urban modeling, relying on powerful algorithms and development technologies. Stereo surround is suitable for individual higher objects and can obtain more detailed data through multi angle photography. And intelligent photography is the most convenient, which can quickly obtain on-site images and facilitate later data analysis.