When it comes to software for drone surveying, Pix4D is one of the best options available. COPTRZ takes a closer look at some inspiring case studies, and asks how UAV operators can utilize its features to get the most out of their drone data
There’s certainly no denying commercial drone technology is revolutionizing many difference industries – not least surveying. With the right technology and training, qualified UAV operators now have the have the ability to provide the most progressive services in the surveying marketplace. From property and construction to land surveying, archaeology and much more, drones have well and truly invaded this field and provide endless opportunities to improve on service and delivery of results.
One of the most challenging parts of a surveyor’s job lies in the interpretation and presentation of collected data. Alongside the increasingly versatile and sophisticated nature of drones themselves, accessible software packages like Pix4D hold the key to getting the most out of drone technology.
A new frontier
As Lisa Chen, Technical Communication Manager at Pix4D, recalls, the transition from more traditional forms of photogrammetry to drones took time.
“I was a surveyor and photogrammetrist before I entered the world of drones,” she says.
“The focus was always large-scale projects, capturing images over a very large area using an aeroplane and very expensive, metric cameras. Angles and orientations were very strict, so at the beginning, many photogrammetrists were sceptical about drone mapping.”
However, the ability for drones to carry out accurate surveying was soon acknowledged, with tests showing precision levels could meet industry standards when flown with the right equipment and training.
“We’re proud to say Pix4D meets the accuracy standards operators need while bringing them real flexibility and freedom from traditional restrictions,” Lisa adds.
Take me to church
Pix4D itself has covered numerous examples of just how accurate a drone equipped with mapping software can be for surveying tasks.
A project to create a 3D model and 3D print of a ruined French abbey provides an awe-inspiring example. In November 2016, French photography and photogrammetry firm Unautregard teamed up with Planete Sports & Loisirs, an aerial photography specialist, and 3D Arcwest, a business with considerable 3D printing experience. Their mission: To combine their respective skills to show just what the latest photography, modelling and printing technology could achieve.
The trio headed for the scenic Ile de Re on France’s western coast, where they undertook the mapping of two distinctly different buildings: the fragmented ruins of the 12th-century Abbey of Chatelier and the church of Ars-en-Re, which dominates the nearby village with its soaring black-and-white spire.
Flying a DJI Inspire 1 equipped with a Zenmuse X5 camera and a DJI Phantom 3 Advanced, the collaborators captured 851 images of the 4,800 square-metre abbey and 1,222 of the 11,600 square-metre church. Each building brought unique challenges – the church, situated in a built-up village, required careful flying and a large photo yield to process. The abbey’s crumbling stone walls also called into question how well 3D modelling and printing could recreate it.
The answer: pretty well. Upon landing, the photographic record of each building was immediately imported through the Pix4D app. From there, Unautregard and their partners processed the images, creating a 3D mesh that accurately reflected the structures. Pix4D also allowed for the automatic extraction of features which would have detracted from the final model – cars and other objects were removed to allow the structures to stand out in the landscape.
The 3D-printed results speak for themselves – accurate, visually arresting replicas of real buildings that have helped Unautregard push the limits of their client engagement.
“A sales pitch is a lot more convincing when showing the complete process with images rather than delivering long explanations,” Guy Dentan from Unautregard explains.
“I spend a lot of time making videos of my different projects to share with future customers and their feedback is always excellent since Pix4D models and exports are of such outstanding quality.”
Weaving wonders with workflows
One of Pix4D’s great strengths is the simple but powerful workflows it offers users. Within a short period of time, a drone operator can set a flight plan, monitor the drone as it automatically captures images and instantly transfer those images upon landing. From there, Pix4D can rapidly process the data to produce maps and models which can then be analyzed and shared with clients via the cloud as the final step. It’s a complete end-to-end process – comprehensive without being complicated.
Details are also well-covered. Using the Pix4Dcapture mobile app, users can smoothly adjust various settings and parameters like altitude, angle, overlap and flight zone boundaries. Following the flight plan you’ve charted, the drone will carry out the hard work itself, navigating the structure or land you’re surveying and capturing images as you’ve instructed. You can even switch to camera view via the app on your phone or tablet to get a drone’s-eye view of just what’s being captured.
As Lisa Chen explains, the flight plan you choose will depend on the surveying job itself.
“Pix4D has several flight plan options for users,” she says.
“Overlap is one of the most important considerations – if you’re mapping a building, for example, you can select the circular flight plan and take images based on the angle you set.”
Pix4D software can be used to process the images afterwards, offering a wide range of different modelling techniques such as point cloud and meshes.
“Within our app we also generate the Pix4D files. If you have Pix4D software installed on your PC the processing will start automatically – everything is done for you as soon as you import.”
Processing can be done via the cloud or your own desktop – for a complex project, a powerful PC with plenty of RAM will deliver a much faster result, and is recommended. Such an approach can also give you more manual input to tweak and edit your models. For example, in the French abbey case study, bushes around the structure were edited out of the 3D model before it was printed.
A PDF containing a full report of your mapping process can be generated at the end of the processing – keeping a paper trail (or indeed a digital trail) of your projects is a great way to measure your output and its quality.
Finally, the cloud can be used to share the final results with your clients or contacts – a seamless and convenient way to show off your work and drive home the power of this amazing technology.
Processing power was a big consideration for our second case study – a 3D model of the iconic hilltop statue of Christo Redentor in Rio de Janeiro, Brazil. With arms outstretched over the home of carnival, samba and sun-soaked beaches, the sheer altitude of the monument also elevates the challenge of photographing it by drone. But that didn’t deter Pix4D.
Collaborating with Aeryon Labs Inc and PUC University of Rio de Janeiro, Pix4D embarked on a project to create the first accurate 3D model of Christo using a drone.
Lisa, who processed the images of the statue, recalls the scale of the task.
“That was one of the toughest projects we did,” she reveals.
“It was difficult to fly the drone in the first place, as it was super windy. We had to get very close to get high resolution shots, but the high altitude made it a tough flight. Pilots need to be skilled to get the best results when surveying – it’s another thing to consider.”
After successfully capturing the statue over multiple flights, processing proved equally painstaking.
“We captured between 7,000 and 9,000 images, a huge amount, and it was quite difficult to fit them all together. One day was super sunny, the next cloudy, which meant we had all these different colours during different lights, and it was difficult to recognise how different parts of the statue fitted together based on photos.
“We found ourselves asking, “Is this the left sleeve, or the right?”
To resolve the problem, Pix4D used their software to process the parts of the statue separately before combining them – a clever fix drawing on a useful feature.
The result was a mind-blowing 3D model of the monument and its environment – proof that even a familiar postcard image can be totally reinvented using drone photography and software, allowing historic sites and structures to be preserved for future generations.
The potential for businesses is huge. From using drones to survey tourist attractions and heritage infrastructure for health and safety checks to delivering 3D models (digital or physical) to customers, who might not be able to visit or experience a site themselves – there are all kinds of applications for innovative entrepreneurs.
For example, imagine how 3D printing might provide cheap, precisely scaled versions of historical sites which people with visual impairments could touch and experience – opening up a whole new subsection of the global tourism market. The possibilities really are endless.
Getting results that count
Of course, to get the most out of Pix4D or any mapping software, operators need to be serious about using it. It’s vital that newcomers to UAV surveying take time to select a high-quality commercial drone and a camera that suits their line of work. Relevant training and flight experience also can’t be overlooked.
“Having the right camera and the right drone is so important,” Lisa agrees.
Understanding how to get the most out of your camera in various scenarios is also key.
“The software is working purely on images, so we have to make sure the image quality is good, the overlap is suitable, and your shots aren’t overexposed or blurred.”
Finally, a firm grasp of the regulations for flying drones in your country, as well as the accuracy expected under national surveying standards, should be the cornerstone of any UAV operator seeking to make inroads into this exciting arena.
Surveying property and real estate is a growing industry for UAV operators. Our third and final Pix4D case study demonstrates just how high-end the output from 3D modelling can be – and also shows how it can give firms a real edge when they’re tendering for lucrative, tech-aware contracts or trying to impress luxury clients.
French real estate company Immoconcept has built up a significant clientele in eastern Europe – customers who don’t always find it easy to visit their high-end properties in France and other parts of western Europe.
To give these potential buyers the chance to experience homes remotely, Immoconcept tapped into drone surveying and 3D mapping with Pix4D. The company decided to produce a 3D model of one of their most prestigious properties, the Chateau Lion, situated 30km from Paris.
The process followed a similar pattern to the two projects we’ve already described. Two different flight plans were used to capture the luxurious chateau and its gardens – one adhering to a grid pattern and one a circle. Using the Pix4Dcapture app, the entire time for both flights was less than half an hour. From there, 109 images were automatically transferred to the Pix4D cloud and processed with Pix4Dmodel software – with the end results ready to share after another half-hour.
As you can see, the outcome was truly spectacular. A photorealistic, georeferenced 3D model of the Chateau Lion was added to Immoconcept’s website, allowing their clients to experience this top-tier property in a way they never had before. Using Pix4D, the possibilities can be pushed even further, with fly-through videos, interactive galleries and more.
“Our customers are mainly based in Russia and can now discover the properties on their own from their home much better than by simply looking at a video,” concludes Immoconcept founder and CEO Irina Duport.
Pix4D: Introduction to 3D Mapping
Pix4D is the leading UAV photogrammetry software, specifically designed for users who want to make 3D maps and point clouds from data captured during a drone flight.
The COPTRZ 1-day Pix4D training workshop aims to give you an overview of Pix4D and how to use the software to give you the data output that you require. The workshop is ideal for those with no previous experience using the software.