Photogrammetry is a process that turns photographs into accurate measurements and detailed 3D models of objects, spaces, or landscapes.
It works by analysing images taken from different perspectives to recreate the shape and appearance of the real world in a digital format. This combination of photography and technology makes it a practical tool for capturing and understanding physical spaces.
With just a camera and the right software, it can document anything from small objects to large buildings or wide landscapes. The resulting models are not only precise but also easy to use for analysis, planning, or sharing information.
This technique is widely used in many fields.
Architects use it to document structures, archaeologists apply it to preserve artefacts digitally, and engineers rely on it to map construction sites efficiently. Even creative industries like video games and films benefit from its ability to produce realistic 3D environments.
This article will introduce you to photogrammetry, explain how it works, and explore why it’s becoming a valuable tool for professionals and learners in architecture, engineering, design, and beyond.
Without further ado, let’s get to it.
How Photogrammetry Works
If you’ve ever wondered how photogrammetry turns regular photographs into 3D models, the process is simpler than it seems.
It involves capturing a series of overlapping photos and using specialized software to process them into a detailed digital representation. While the results may seem complex, the process itself follows clear and logical steps.
Understanding these steps can help you see how photogrammetry can be applied to a variety of projects, whether you’re creating a model of a small object, a building, or an expansive landscape.
Let’s break down the process into its main stages to see how everything comes together.
Step 1: Capturing Images
The first step in photogrammetry involves photographing the subject from multiple angles.
The goal is to capture overlapping areas in the images, as these common points allow the software to align and analyse them.
For smaller objects, a handheld camera or smartphone works well, while drones are ideal for larger areas like landscapes or construction sites.
Factors like consistent lighting, proper focus, and avoiding motion blur are critical for obtaining high-quality photos that contribute to an accurate model.
Capturing images systematically is important for successful photogrammetry.
For example, a photographer may circle an object or structure, ensuring they photograph it from all sides. For larger spaces, a grid-like pattern may be followed to ensure complete coverage.
The more overlap and detail the images contain, the more accurate the final 3D model will be.
Step 2: Processing the Images
Once the photographs are captured, they are uploaded to photogrammetry software for processing.
The software identifies and matches common points between overlapping images, using these points to calculate the relative positions and angles of the camera for each photo.
This process creates a network of spatial coordinates, known as a point cloud, which serves as the foundation of the 3D model.
Modern photogrammetry software automates much of this process, applying algorithms to analyse image data and minimize errors.
Depending on the scale and complexity of the project, processing can take anywhere from a few minutes to several hours. For large-scale models, powerful computers or cloud-based solutions may be used to handle the data.
Step 3: Generating the 3D Model
After the point cloud is constructed, the software generates a 3D model.
This step involves connecting the points to form a mesh, which is essentially a framework of the object’s surface. Textures and colours from the original images are then applied to the mesh, resulting in a realistic and visually detailed model.
The final model can be exported for use in various applications.
Architects and engineers may integrate it into design workflows, archaeologists can study and preserve artefacts, and digital creators might adapt it for visual effects or video games. Models can also include metadata, such as measurements and material properties, depending on the software used.
Step 4: Refining and Analysing the Model
The generated model can be further refined to suit specific project needs.
For example, noise or errors may be cleaned up, additional measurements might be added, or the model could be optimised for compatibility with other software platforms.
In many cases, these models are shared across teams, allowing collaboration and analysis.
Photogrammetry’s ability to turn photographs into detailed 3D models makes it a versatile tool for professionals in architecture, engineering, heritage preservation, and beyond.
The process not only saves time compared to traditional measurement methods but also provides a rich, interactive representation of real-world objects and spaces.
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Types of Photogrammetry Methods
Photogrammetry isn’t a one-size-fits-all approach.
The method you choose depends on your project, the environment you’re working in, and the level of detail you need. Let’s explore the different types of photogrammetry methods so you can see which one might suit your needs best.
1. Aerial Photogrammetry
Imagine you’re tasked with mapping an entire city or monitoring a large forest.
Aerial photogrammetry is the go-to method for projects like these. Using cameras mounted on drones, planes, or satellites, this approach captures a bird’s-eye view of vast areas. The images are often taken in overlapping patterns to ensure no detail is missed.
This method is especially popular in urban planning, land surveying, and environmental monitoring. For example, construction teams might use aerial photogrammetry to plan large infrastructure projects or track progress on sites spread over miles.
Where it’s useful: Mapping landscapes, creating topographic maps, and monitoring land changes.
2. Terrestrial Photogrammetry
For projects that require close-up detail, like inspecting a building or documenting an artefact, terrestrial photogrammetry is your best option.
With a camera in hand or on a tripod, you capture images from multiple angles at ground level. This method is ideal when you need to study structures, monuments, or smaller objects up close.
Architects, archaeologists, and engineers often use terrestrial photogrammetry for detailed work. For instance, this method is perfect for creating accurate 3D models of historical landmarks or assessing structural damage after a natural disaster.
Where it’s useful: Documenting buildings, preserving historical sites, and small-scale inspections.
3. Underwater Photogrammetry
When your project dives below the surface, underwater photogrammetry becomes essential.
This method uses waterproof cameras operated by divers or remotely operated vehicles (ROVs) to capture overlapping images of underwater environments.
Marine archaeologists use this method to map shipwrecks, while environmental scientists monitor coral reefs or underwater ecosystems. It’s a unique and powerful way to study areas that are otherwise hard to access.
Where it’s useful: Exploring marine archaeology, monitoring underwater habitats, and inspecting underwater pipelines.
4. Satellite Photogrammetry
For projects that span regions or even continents, satellite photogrammetry is the answer.
High-resolution images taken from space allow for large-scale analysis, such as tracking deforestation or monitoring climate change over time.
Government agencies, environmental organisations, and researchers rely on this method for its ability to provide a macro perspective. For example, satellite photogrammetry has been crucial in disaster management, such as mapping areas affected by floods or wildfires.
Where it’s useful: Climate studies, disaster management, and large-scale mapping.
5. Stereo Photogrammetry
If precision is your main focus, stereo photogrammetry is the method to consider.
This approach uses two or more images taken from slightly different angles to create a highly detailed 3D model. Industries like aerospace and automotive rely on stereo photogrammetry for its ability to deliver accurate measurements.
For example, engineers might use this method to analyse the shape of a mechanical part or ensure components fit together perfectly during manufacturing.
Where it’s useful: Precision engineering, quality control, and product design.
Accelerating Photogrammetry Workflows with GPUs
Photogrammetry often requires processing large amounts of data, especially when working with high-resolution images or complex projects.
This can make tasks like aligning images or creating 3D models time-intensive. Graphics Processing Units (GPUs) can speed up these workflows significantly, making them an important tool for photogrammetry professionals.
GPUs are designed to handle parallel processing, which means they can process multiple calculations at once.
This capability makes them perfect for tasks like generating point clouds and reconstructing 3D surfaces, which involve analyzing thousands of data points simultaneously.
When paired with photogrammetry software that supports GPU acceleration, such as Agisoft Metashape or RealityCapture, GPUs can cut processing times dramatically, helping you work more efficiently.
Using a GPU doesn’t just save time; it also allows you to work on larger projects without compromising quality.
Whether you’re handling hundreds of images or creating detailed models, GPU acceleration ensures smoother and faster performance, letting you focus on the results rather than the wait. For professionals and students alike, integrating GPUs into photogrammetry workflows can make a significant difference in productivity and project outcomes.
History and Future of Photogrammetry
Photogrammetry has roots that stretch back centuries, evolving from simple techniques to advanced digital processes that we rely on today.
The concept first emerged in the mid-19th century, shortly after the invention of photography. Early practitioners discovered that overlapping photographs could be used to determine distances and create maps, laying the groundwork for modern photogrammetry.
Over time, the field progressed alongside technological advancements.
By the mid-20th century, aerial photogrammetry became a cornerstone of cartography and urban planning, aided by developments in aviation and camera technology.
The transition from analogue to digital techniques in the late 20th century marked a significant leap forward, introducing software that could process large datasets with increasing speed and accuracy.
Today, photogrammetry has become more accessible than ever.
Cameras, drones, and powerful computers allow professionals and hobbyists alike to create detailed 3D models and maps. Industries such as architecture, archaeology, and engineering continue to push the boundaries of what photogrammetry can achieve.
Looking ahead, the future of photogrammetry is tied to advancements in AI and machine learning.
These technologies are poised to automate many aspects of the workflow, making the process even faster and more intuitive. Additionally, the integration of photogrammetry with tools like augmented reality (AR) and virtual reality (VR) is expected to unlock new possibilities for visualising and interacting with 3D data.
From its early days to its current role in shaping modern industries, photogrammetry has shown a remarkable capacity for growth.
As technology continues to evolve, the potential applications of photogrammetry will only expand, offering exciting opportunities for professionals and innovators alike.
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Photogrammetry Is the First Step in Your Learning Journey
Photogrammetry plays a vital role in fields like architecture, construction, and design, complementing tools like BIM, AutoCAD, and Revit. To fully harness these technologies, building expertise in CAD and BIM workflows is essential.
Interscale Education offers the perfect opportunity to develop your skills through structured learning. Our certified BIM, AutoCAD & Revit online course includes:
- Weekly live classes and interactive Q&A sessions led by experienced instructors
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- Industry-recognised certification to validate your skills
- Expert guidance to help you align your training with your career goals
Learn in a collaborative environment designed to prepare you for success. Whether you’re an architect, engineer, or designer, this course equips you with the tools and knowledge to excel in your projects.
Begin your journey with our certified BIM, AutoCAD & Revit online course—register today!
