Error: Black Holes in the Point Cloud - green, orange and yellow Rectangles in the Overlap Map in the Quality Report - PIX4Dmapper

Error

• Green, orange and yellow patches in the Overlap map in the Quality Report.
• Black holes (black rectangles or sharp triangles) in the model where no data is generated.

Description

• Green, orange and yellow patches in the Overlap map in the Quality Report.
• Lower accuracy in the position of the 3D points.
• Black holes (black rectangles or sharp triangles) in the point clouds.
• Rectangles in the DSM.

Cause

This issue appears if there is not enough frontal and/or side overlap.

Even if there are enough keypoints found on each image, there might be some areas that can only be seen in 2 images.

The Densified point cloud is generated using the Automatic Tie Points and, by default, only contains keypoints that can be identified in at least 3 images. All outputs depending on the Densified point cloud will be affected.

Solutions

Use keypoints found in 2 images as keypoints for the Point Cloud Densification:

1. In the menu bar, click Process > Options...
2. Select the tab Point Clouds.
3. In the section Minimum Number of Matches, instead of 3, select 2.
4. Click OK.
5. Process step 2 again.

If the problem persists:

Add and mark Manual Tie points on the problematic areas, and process step 1 again. For more information about how to add Manual Tie Points: How to import and mark Manual Tie Points (MTPs)

If the problem persists:

Fly again using higher frontal and side overlap and process the project again. For more information about the flight plan design: Step 1. Before Starting a Project > 1. Designing the Image Acquisition Plan.