Issue Description
Reconstruction effects are not ideal in DJI Terra for visible light reconstruction, i.e., encountering issues such as blurring, ghosting, misalignment, distortion, and other phenomena.
Possible Cause of Issue 1: The photos have insufficient overlap.
For example, the flight altitude is insufficient when shooting tall buildings. This could result in insufficient top and side features in the photos.
Solutions
It is advisable to retake photos to increase the overlap rate or create the flight route and perform the mission again.
💡 [Tips] It is recommended to set the Forward Overlap Ratio to 80% and the Side Overlap Ratio to 70%. Those settings are suitable for most scenarios.
1. For those areas with great elevation changes (large difference in the overlap rates between the lowest area and the highest area), in order to ensure the overlap rate in the highest area, it is recommended to increase the overlap ratios or plan flights at different altitudes.
2. In flat areas where the overlap rates in different area are close, it is recommended to appropriately reduce overlap ratios to increase the efficiency of aerial mapping and to decrease the workload of data processing. However, it is important to ensure that the Forward Overlap Ratio is no less than 65% and the Side Overlap Ratio no less than 60%.
Possible Cause of Issue 2: There are weak texture features or moving objects in the shooting scene.
1. For example, when shooting water, glass, or buildings with large single-texture surfaces, the photos cannot reflect the true texture of objects.
2. For example, on a road with heavy traffic or vegetation swaying in the wind, the movement of objects causes changes in the geographic positions of feature points, making it impossible to match them correctly.
Solutions
These issues belong to principle issues in photogrammetry. At this stage, such issues are unavoidable. It is recommended to carry out model repair processing at a later stage.
Possible Cause of Issue 3: Complex or hollow architecture
For example, it is difficult to cover all surfaces of those objects during shooting, such as guardrails, base stations, iron towers, high-voltage lines, etc. And some small structures have low resolution, making it difficult to identify effective feature points.
Solutions
It is recommend to reshoot some high-resolution photos closely to enrich its texture features.
If the issue cannot be resolved through the above solution, please contact DJI Support for further assistance.
