21 Jul 2017

Knowing which flight plan to choose for 3D modeling can be challenging, but the good news is that Pix4Dcapture has automatic flight missions optimized for different scenarios

To help you compare, we tested variations in image-angle overlap in circular missions

Circular missions are recommended to 3D map a single object of interest, like a building or a monument.

When it comes to circular mission settings, with Pix4Dcapture, you can choose the angle between images.

By dividing the 360° flight covered by the drone into sections, or variable angles (4°, 8°, 12°), the drone is told by the app to shoot a picture when it reaches the predefined angle.  

At a practical level, this means that at a low angle value (e.g. 4°), the drone will take more images and have a bigger image overlap than a higher angle value (e.g. 12°).

For this test, we flew the three missions around a building with a base of 30 x 30 meters and height of 18 meters, using a DJI Phantom 4.

Each mission had a different value for the “angle between images” setting; we tested capturing images with 12°, 8° and 4°.  

As constant factors, the flight altitude was 40m and the data was processed on Pix4D Cloud.

Circular mission with 12° angle between images

Flight time: 4 min 29 s
Number of images 31
Cloud processing time: 10 min 8 s
Average GSD: 3.11 cm / 1.22 in

Circular mission with 8° angle between images

Flight time: 5 min 44s
Number of images 62
Cloud processing time: 17 min 23 s
Average GSD: 2.87 cm / 1.13 in

 

Circular mission with 4° angle between images

Flight time: 9 min
Number of images 124
Cloud processing time: 35 min 23 s
Average GSD: 2.84 cm / 1.12 in

 

How do I choose the angle between images in circular missions?

To answer this question, it is important to define a goal of the 3D mapping project and keep in mind time and quality constraints.

By using a higher overlay level, there is more image information for the software to reconstruct an object, resulting in a more detailed 3D model. However, more data implies more time spent flying and acquiring images, and also a longer processing time.

Depending on the purpose of the 3D model,  the option to manage the angle between images helps to balance time and quality: allowing you to choose from faster and more schematic reconstructions to more detailed ones.

 

So, what are your project goals and constraints?

Start flying with Pix4Dcapture today!