4 Ways to Improve the Accuracy of Your Drone Models with 3D Mapping Software


Tips and Tricks for Making the Most of 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 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:

  • Collect high-quality nadir images
  • Capture oblique imagery
  • Plan tiered flights at varying heights
  • Capture additional oblique photos from multiple angles
By following a few simple tips, you can create 3D models that look more like the “after” picture and less like the “before” picture

Collect High-Quality Nadir Images

To improve the accuracy of your drone-generated models, it’s important to first understand how 3D mapping software works. After you fly your area of interest and upload your aerial imagery to DroneDeploy, our 3D software matches the common points between those images to create a model. The more common points that can be matched, the higher the accuracy of the model.

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.

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]

This model was created without capturing oblique images
Notice the difference when oblique images are included. Capture oblique images to dramatically improve the quality of models made using 3D mapping software

New feature: DroneDeploy’s orbital flight mode

There are several ways to capture oblique images, but the newest, and simplest, is DroneDeploy’s orbital flight mode. In the app’s flight plan settings, simply enable “orbit at end of mission.” This allows you to automatically capture oblique photos of a structure located at the center of your map. The orbit is performed at the set flight altitude and in most cases within the flight boundaries. The camera angle is adjusted automatically, depending on flight altitude and distance from center.

Easily enable DroneDeploy’s new Orbital Flight Mode feature

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.

Tarek Maalouf made a model of this house (picture left) and then greatly improved its accuracy (picture right) by employing a few simple techniques, including tiered flights at multiple heights. Explore the final model

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.

Fearghus Foyle of Aerial Eye made an accurate 3D model of an Irish castle by capturing three sets of oblique images taken at various heights and angles. Read more here.

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 these posts:

This post was syndicated from DroneDeploy

The post 4 Ways to Improve the Accuracy of Your Drone Models with 3D Mapping Software appeared first on RC Drone Zone.



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