Create 3D Models of Your Underwater Assets with Photogrammetry

What is Photogrammetry

3D Photogrammetry is a technique that involves capturing multiple photographs of an object or scene from different angles and then processing them to generate a 3D model.

Combining underwater inspections and 3D models can provide valuable and more accurate information about your asset’s condition.

This technology is therefore particularly well suited for the inspection of port structures, vessels, quays, mooring chains, water tanks, offshore wind farms, and other underwater structures. When it comes to capturing underwater assets, the challenges are quite unique.

Underwater Photogrammetry Challenges

Underwater photogrammetry is a specialized field that involves capturing and reconstructing 3D models of underwater assets. However, this process comes with its own set of unique challenges.

  • Limited visibility – Unlike above-water environments, water conditions vary significantly, reducing clarity and visibility. Murky water, sediment, or algae can obscure the details of the underwater assets, making accurate capture and reconstruction difficult.
  • Water Hazards – Besides visibility issues, water can also come with substantial physical hazards. Frigid temperatures, high currents, or dangerous objects can make it extremely difficult or dangerous for humans to enter the water for surveying.

Robotic ROVs for 3D Photogrammetry Modelling

Underwater photogrammetry requires specialized equipment like robotic ROV’s to overcome the challenges unique to underwater environments. Ordinary cameras and equipment may not withstand the water pressure, maintain proper distance from the object, or deliver the required image quality.

  • Data Acquisition

The initial step in 3D modeling involves gathering high-resolution images. For photogrammetry purposes, it is necessary to have a complete view of the entire object and then move around it to capture images from various angles.

Blue Atlas underwater robot “Sentinus” can survey along the x-axis and y-axis and even explore the depths of underwater assets, such as ship hulls.


From these recorded videos, we extract individual images that will serve as the input for our photogrammetry pipeline. It is essential to ensure that the images are of high resolution, as this will directly impact the quality and accuracy of the final 3D model and of the applied texture.

Blue Atlas Robotics Sentinus ability to get significantly closer to the object than larger equipment, is also perfect for capturing high-quality footage with even lighting and low backscatter.


  • 3D point cloud Construction

With our dataset in hand, the next step involves generating a 3D point cloud. It is important to align the input images to get a point cloud so that the points we extract are placed spatially correctly.

Image alignment is a critical process, as it ensures that the points extracted from the images are placed spatially correctly. By identifying common features between images and matching them, we can determine the camera positions and orientations relative to the object. This alignment allows us to create a cohesive and accurate 3D representation.

After the alignment, we then have a 3D point cloud extracted from all the images from all the cameras.

  • Photographic 3D Modelling

Once we have the 3D point cloud, we move on to the process of creating the 3D model.

The mesh is a surface representation of the object, composed of vertices, edges, and faces that define its shape. At this stage, the mesh does not have any color or texture.

The final step in the photogrammetric modeling process involves adding texture to the 3D mesh. Texturing is vital for providing realistic visual details to the model.

Benefits of having 3D models using Blue Atlas ROV

  • Enhanced Visualization: 3D models provide a clear and comprehensive visualization of underwater structures and environments. The advanced technology, combined with eight strategically placed highcameras on the robot, ensures that every detail is captured with utmost accuracy and the result is a highly detailed 3D model.

    This visual representation allows inspectors and stakeholders to understand the condition of submerged assets more effectively. The potential defects, corrosion, or any other issues can be identified promptly, allowing for timely maintenance and repair, thus saving time and resources.


  • Data Archive and Comparisons: 3D models provide a valuable data archive that can be revisited for future inspections and comparisons. This historical data aids in tracking changes over time and understanding asset degradation or growth patterns.

    The data can be stored and managed in our cloud-based platform which makes it easy to retrieve and compare it at any point in time.