Have you ever considered creating an accurate and detailed 3D model from 2D photos? Probably not, it’s incredibly difficult. Now, if you try to do it on a truly massive scale and have a huge castle as your subject, it makes it almost impossible to do by hand. The guys at Pix4D took it as a challenge to their software and not only modeled the outside, but also the inside of the castle, all in one interactive 3D model. To prove that it can be done by anyone, they decided to  use only consumer cameras (GoProDSLR and a Mirrorless).

Chillon Castle (“Chateau de Chillon”) is Switzerland’s most visited historic monument and one of the most complex structures in the country, which is why Pix4D chose this location to test out the software (Pix4Dmapper) they developed in the past few years. The software is capable of automatically processing normal 2D photos, and produce a very accurate 3D model. No manual work is needed except for choosing the images the software is going to analyze.

 The goal of this project was to do a fun and instructive project to use the latest features of our software (Pix4Dmapper) and publish a white paper on it. These latest features are the use of the GoPro, Fisheye lenses and combination of both aerial and ground imagery in one project and were introduced with V1.1 of Pix4Dmapper in late April of this year.”

In order to capture all the images, Pix4D  sent a team of 7 people who spent a total of just 4 hours shooting the castle from every angle possible. All the camera systems they used were consumer-available products and not expensive and hard-to-get equipment. For any of the ground shots they used the Canon 6D with a 8mm Fisheye lens and a Sony alpha 7r mirrorless with a 8mm Rikonon fisheye lens. ​ Each shot was taken approximately 1 meter apart​.

For the birds-eye view shots, they used a DJI Phantom 2 Vision with its integrated camera with a Fisheye lens and also by using the GoPro Hero 3+ mounted on a custom Quadrocopter.

Data acquisition: just under 4 hours for 6 people (the 7th person took care of the geo-referencing) using the various drones and cameras to produce the 6227 images. There was no editing involved. Pix4Dmapper, our software, processed the images to convert them to the 3D point cloud. The processing and merging of the full project took 5 days, though approx. 80% of this time is “computer processing time” meaning that you don’t have to intervene manually and just can let the software and computer do “their thing”

A total of 6,227 images were taken to complete the project – both from the ground (indoors and outdoors) and from above. when you see the scale of the castle, and the amount of detail in the model, this number probably seems a little low. But their software is able to analyze the images and produce one of the most accurate 3D models available on the market.

The workflow of our software is fully automatic, meaning that you don’t need to be a photogrammetry specialist to convert imagery into a 3D model. The aim of our technology is accuracy as our clients are mainly civil engineers and architects that need the geo-referenced models and maps our software produces for their work that asks for precision.”

Article by Noam Galai

To read more about the project and how it was done, check out Pix4D project page.