Big triangles generated in the DSM

Problem

The DSM shows some artifacts: big area(s) formed by triangles. 

 DSM_big_Triangles.jpg

Cause

The external triangles: The mapped area present concave zones and no Processing Area has been draw so the software triangulates positions and fills in the holes with the triangles. 

 

The internal triangles: The problem is related to images not calibrated in the affected area due to low overlap. If the project has constant overlap and the problem is still produced, the reason is that the affected area is more difficult to reconstruct and less keypoints could be found and therefore, the images could not be calibrated.

 

DSM_big_Triangles2.jpg DSM_big_Triangles3.jpg
Optimized Camera Position 2D Keypoints Graph

 

Solution

In order to solve the external triangles

1. Draw a Processing Area around the desired area (the drawn area can have concave zone) following: 202560179.
2. Process the 3. DSM, Orthomosaic and Index again.

 

In order to solve the the internal triangles

1. Calibrate manually the affected images following: 202560189.
2.  Change the processing options:

2.1. On the Menu bar, click Process > Processing Options...
2.2. On the 1. Initial Processing tab, in the section General, change the Keypoints Image Scale to: 2 (double image size).
2.3. On the 2. Point Cloud and Mesh tab, in the section Point Cloud Densification:

2.3.1. Change the Image scale  to: 1 (original image size, slow).
2.3.2. Change the Point density to: High (slow).
2.3.3. Change Minimum number of matches to: 2.

 
Important: The mentioned options above will request more processing time and may fail if the Computer hardware resources are low, it is suggested use it when having the recommended system requirements: 202557289.

3. Process the project again.

4. If the processing fails due to low hardware resources or the Images are calibrated but the big triangles still appear, fly the affected zone again with higher overlap (with same light and weather conditions) and create a new project including the mentioned images.

 

 

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