5 Ways to Improve the Accuracy of Your Drone Models with 3D Mapping Software
3D mapping software has the potential to revolutionize workflows across a host of industries. Many professionals already use 3D modeling software to create accurate, drone-generated models. But as with any technology, creating an accurate model with 3D mapping software takes some practice.
The good news is that by using DroneDeploy—or making a few adjustments to your process—you can greatly improve the accuracy of your models.
Below, we discuss the following tips for improving the accuracy of your drone-generated 3D models with 3D mapping software from DroneDeploy:
- Use DroneDeploy’s New Structures Mode
- Collect high-quality nadir images
- Capture oblique imagery
- Plan tiered flights at varying heights
- Capture additional oblique photos from multiple angles
Use DroneDeploy’s Structures Flight Mode
There are several ways to create crisp 3D models with your drone. But the simplest way is DroneDeploy’s Structures flight mode. It’s designed to automatically collect the lowest number of images required to make a good model.
Using Structures mode is easy. In the app’s flight plan settings, enable “Structures Mode” with a flip of the toggle. This allows you to automatically capture predefined photos of a structure located at the center of your map.
In Structures Mode, your drone will fly along the perimeter of your flight plan and take images every 5 meters, between 60 and 50 degrees down, looking towards the center of the map area. The image are captured at the flight altitude set when planning your flight.
Give Structures Mode a try during your next flight. You can also learn more about Structures Mode here.
Collect High-Quality Nadir Images
If you wish to capture aerial images manually, you can still make a great 3D model. But it will require more work.
The first step to making your model is collecting a high-quality set of nadir images — images taken from an overhead view with your drone’s camera pointing straight down at the ground — just as you would when generating any orthomosaic map. The higher the resolution and quality of these images, the more data points the 3D mapping software has to work with, and the greater the probability of matching common points on the model.
In an earlier post, we outlined seven ways to improve the accuracy of your orthomosaic drone maps. These tips are equally important when capturing nadir imagery for 3D models. They include:
- Increase Image Overlap- Increasing both sidelap and frontlap to at least 80% creates more matched points and greater accuracy, even at lower altitudes. Remember that overlap is reduced over tall buildings and trees.
- Fly at a lower altitude- This both captures more detail and increases the number of images, which in turn creates more possibilities for the 3D mapping software to match common points.
- Use a camera with a mechanical shutter- Upgrading to a mechanical shutter camera (e.g. DJI Phantom 4 Pro) reduces the rolling shutter effect, which can warp images and make it difficult for 3D mapping software to match points.
- Consider the weather and time of day- To minimize shadows, ideal flying conditions are midday or overcast weather.
This process can be automated with DroneDeploy, but you’ll manually want to collect Oblique images as well. Read on to learn how.
Include Oblique Imagery
In addition to nadir imagery, it is important to also capture oblique imagery — or a side-view perspective — for any vertical structure you are modeling. Here, it might be helpful to think of your drone as a spray can, and the images as paint. To make an accurate model, you want to take enough pictures to coat the entire structure with one coat of paint. This means taking pictures of the entire surface area of the structure.
3D modeling, rendering and animation expert Jeff Foster, co-founder of Sound Visions Media and editorial director of Drone Coalition, recommends flying two additional orbital flights around a structure to capture oblique imagery and improve the accuracy of your model.
To improve the accuracy of 3D models, fly at least two orbital flights around a structure, recommends Drone Coalition’s Jeff Foster. [click-to-tweet]
Plan Tiered Flights at Varying Heights
DroneDeploy’s manual orbital flight mode captures one set of oblique images taken at the same altitude as the original mission. Depending on the structure being modeled, some drone operators choose to capture additional sets of oblique photos as well. It is always possible to capture oblique images manually and include these in your DroneDeploy upload. Because all drone-generated images are geotagged, you can take them in any order and DroneDeploy’s 3D mapping software will recognize them and arrange them into your model accordingly.
Tarek Maalouf creates drone-generated 3D models and prints for architects, builders and construction companies, and also produces custom drones through his company, Maalouf Properties LLC. For a one-story building, he recommends two manual orbital flights, taken at roughly equidistant heights. On a two-story building, he increases to three passes. On a three-story building, he increases to five passes.
“The key is planning out ahead of time how many pictures I take,” advises Tarek. “It’s not so much how many pictures you get that’s going to make the better model.” Instead, he says, it’s all about taking the right pictures at the right heights.
For the house pictured below, Tarek captured about 40 images per orbit.
Capture Additional Oblique Photos from Multiple Angles
A final point to consider is the angle at which you capture oblique photos. 3D mapping software is able to stitch oblique images best when there is no sky in the background, although that is sometimes unavoidable. Steeper camera angles usually capture less sky. That being said, flying at least one orbit at a lower altitude and a shallower angle is helpful when creating a 3D model of an object that has overhanging features, such as roofs, eaves or archways.
Fearghus Foyle of Aerial Eye, one of Ireland’s leading UAV services companies, recently created a 3D model of an eighteenth-century castle using this method. As you can see in the diagram below, he captured three sets of oblique images taken at various heights and angles.
As you gain more experience with 3D models, you will find the angles and heights that work best for each type of project. As a good starting point, we recommend at least two orbits:
Oblique orbit 1: 45 degrees, same height as the original nadir flight.
Oblique orbit 2: 30 degrees, at about half the altitude.
Practice makes perfect. Creating drone-generated 3D models is no exception. By following these tips, you will be well on your way to making the most of DroneDeploy’s 3D mapping software.
Where to Learn More
Our 3D Model Guide will walk you through all the tips discussed above in greater detail. If you are ready to get started and want to try DroneDeploy’s new orbital flight mode, also make sure to read our recent product release wrap up to learn more about this and other exciting new features. Learn more about improving your 3D models and overall drone map accuracy in this post: