High-Resolution 3D Digital Twin of a Large Open Pit Gold Mine for a Feature Film
Summary
Queensland Drones captured a high-resolution 3D model of one of Australia’s largest open pit gold mines, commissioned on behalf of a Hollywood production company to become a CGI set for a feature film.
To achieve this, given the challenge of the pit size and depth, we combined two drones: a Delair UX-11 fixed-wing for the upper section, and a DJI Phantom 4 Pro multirotor for detail inside the pit. PPK correction from a shared base station allowed both image sets to merge tightly into one model. The production company received a 3D OBJ model, plus a DEM, high-resolution orthomosaic and detailed elevation contours.
| Project fact | Detail |
|---|---|
| Client | A location scouting company commissioned by a Hollywood movie production company |
| Purpose | 3D digital twin of a mine to become a CGI set for a feature film |
| Site | One of the largest open pit gold mines in Australia |
| Capture method | Drone photogrammetry (camera-based 3D mapping) |
| Upper section | Delair UX-11 fixed-wing UAV with a 24 MP mapping camera |
| Inside the pit | DJI Phantom 4 Pro multirotor with a 20 MP camera |
| Positioning | PPK correction to merge the two image sets using a shared base station and accurately measured ground controls |
| Outputs | 3D OBJ model, DEM, high-resolution orthomosaic, detailed elevation contours |
| Area and pit size | The open pit is approximately 300–400 m long, 200–300 m wide, and about 75–80 m deep |
| Capture date | October 2022 |
The challenge
A film’s visual effects team needed the mine pit as a digital set: accurate in shape, convincing up close, and complete from the rim to the pit floor. A CGI set is judged by eye. Camera moves in the finished film could sweep across the whole pit or push in close to a bench wall, so the model had to hold up at both scales.
- Scale. One of Australia’s largest open pit gold mines covers a very large area. A multirotor alone would need many flights and days to cover it at mapping height.
- Depth and steep walls. A deep pit with steep, benched walls is hard to capture well from high above. The walls and floor need closer imagery to avoid stretched, blurry texture in the model.
- Texture, not just shape. Survey models are judged on accuracy; a film set is also judged on how real it looks. The imagery had to carry sharp, true-colour texture across the walls and floor.
- An operating mine. The pit was still active, with excavators and other heavy equipment working on the floor. The survey was conducted in close collaboration with the mine’s safety team.
- Confidentiality. The film was unreleased, so the work had to stay under wraps.
Methodology
We used each aircraft for what it does best: the fixed-wing for wide coverage, the multirotor for close detail inside the pit, with PPK positioning tying them together.
- Choosing photogrammetry. An open pit is almost bare rock and soil, with no vegetation to see through. That removes LiDAR’s main advantage, while photogrammetry delivers the true-colour, high-detail texture a film set needs, at lower cost.
- Fixed-wing for the upper section. The Delair UX-11 fixed-wing, carrying a 24 MP mapping camera, flew the upper section and surrounding area. A fixed-wing covers far more ground per flight than a multirotor.
- Multirotor for detail inside the pit. The DJI Phantom 4 Pro, with its 20 MP camera, flew lower inside the pit to capture the benches, walls and floor in finer detail.
- PPK positioning. PPK (Post-Processed Kinematic) correction gave precise camera positions, so the two image sets could be merged tightly into one model without visible seams or misalignment.
- In-house processing. Our team processed all the imagery in-house into a single 3D model. That suited a confidential production as well as a technical one.
- Outputs for two audiences. The textured 3D model went to the visual effects team as an OBJ file. The same data produced survey-style outputs: a DEM, a high-resolution orthomosaic and detailed elevation contours.
Deliverables
The project delivered four outputs from one capture: a textured 3D model for the visual effects team and three survey-style products.
| Deliverable | What it’s used for |
|---|---|
| Textured 3D model (OBJ) | Imported into visual effects software as the base of the CGI set |
| Digital Elevation Model (DEM) | Accurate terrain heights across the pit and surrounds |
| High-resolution orthomosaic | True-scale plan view of the whole site, for layout and reference |
| Detailed elevation contours | The pit’s benches, ramps and floor levels as linework |
OBJ is a widely supported 3D format, so the model can be opened in most 3D and visual effects software.
Validation and quality
For a film set, the test is whether the merged model holds together: consistent scale and alignment from rim to floor, and sharp texture everywhere a camera might look.
- Two aircraft, one model. PPK-corrected camera positions from a shared base station are what let the fixed-wing and multirotor imagery merge tightly. Without them, the two sets could sit slightly apart and leave seams or steps where they meet.
- Resolution where it counts. Flying the multirotor lower inside the pit put more detail on the walls and floor, where close-up detail matters most. But flying the entire project with the multirotor would have been too complex and time-consuming. The entire data capture was completed, under the supervision of mine staff and the production company, in a single working day.
- Survey-style checks. The DEM, orthomosaic and contours come from the same model, so they also serve as a check on its shape and scale.
Accuracy context: for survey work, our drone photogrammetry at this time typically achieved around 2–3 cm horizontal and 5–6 cm vertical under good conditions. With surveyed ground control points and independently measured checkpoints, results as tight as 1.5–2 cm horizontal and 2.5–4 cm vertical have been verified. These are general figures, not results measured on this project. See How accurate are drone mapping surveys?
Client outcome
The production received a complete, high-resolution 3D digital twin of a real Australian gold mine, ready to become a CGI set for its feature film.
- A real location, digitally: the visual effects team could build scenes around the actual mine without reconstructing it by hand.
- One capture, many uses: the same data produced the OBJ model, DEM, orthomosaic and contours.
- Confidential throughout: processing stayed in-house, and the project details stayed private until the production allowed otherwise.
- The right sensor for the site: photogrammetry gave true-colour texture across a bare, unvegetated pit at a lower cost than LiDAR.
Frequently asked questions
Can drones create 3D models of real locations for film and visual effects?
Yes. Drone photogrammetry captures thousands of overlapping photos and turns them into a textured 3D model of a real place. Queensland Drones captured a high-resolution 3D model of a large Australian open pit gold mine, commissioned on behalf of a Hollywood production company, to become a CGI set for a feature film.
Is photogrammetry or LiDAR better for mapping an open pit mine?
For a bare, unvegetated pit, photogrammetry is usually the better choice. LiDAR’s main advantage is reaching the ground through vegetation, which an open pit doesn’t have. Photogrammetry also captures true-colour texture, which matters for visual work. LiDAR is the better choice where vegetation or difficult lighting would hide the surface. With the benefit of current enterprise grade LIDAR systems with concurrent RGB image capture, we may have used both options if capturing this site today as PPK LIDAR data can generate even more accurate positional data to capture detailed 3D models.
Why use both a fixed-wing and a multirotor drone on one project?
A fixed-wing drone covers large areas quickly and efficiently, which suits the wide upper section of a big mine. A multirotor can fly lower and more slowly inside the pit to capture fine detail on walls and floor. Combining them gives both coverage and detail.
What is PPK and why does it matter when merging drone imagery?
PPK (Post-Processed Kinematic) positioning corrects each photo’s GNSS position after the flight against a base station, giving centimetre-level camera positions. When imagery from two aircraft is combined, precise positions are what let the two sets line up into one seamless model.
What is an OBJ file?
OBJ is a widely supported 3D model format that stores a model’s shape and links to its texture images. It opens in most 3D, visual effects and game-engine software, which makes it a common hand-over format for film work.
Can drones be flown inside an operating mine?
Yes, with the operator’s permission, site inductions and safety controls, and within CASA rules. For this project, all operations were overseen by mine safety staff and conducted within the mine’s own SWMS model.
Need a mine, quarry or location captured in 3D?
Queensland Drones is a CASA-certified drone survey, 3D mapping and LiDAR specialist (ReOC #6466), operating since 2016 across Queensland, New South Wales and the Northern Territory. We capture mines, quarries and large sites for surveyors, engineers and production companies, and choose photogrammetry or LiDAR to suit the site.
Give Tony a call on 1300 246 977 or request a quote.
Related: Volumetric Mapping for Mines and Quarries · 9 Key Differences Between Photogrammetry and LiDAR · Film and Documentary Footage · Aerial LiDAR Mapping
