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A Beginner’s Guide to Photogrammetry

With the rise of immersive media and higher quality camera equipment, digital creators are reimagining photogrammetry for use in a variety of industries like entertainment, geospatial, medical, etc., and mediums such as virtual reality (VR), augmented reality (AR), extended reality (XR), and 3D printing.

Are you interested in learning more about photogrammetry? Get started with our Beginner’s Guide to Photogrammetry and see some of the common questions we often hear regarding how photogrammetry works.

What is photogrammetry?
Photogrammetry is a process that uses photographs of real-world objects to create digital 3D representations of those objects (i.e., 3D models). It involves capturing many overlapping images of a structure, object, or landscape.

What is photogrammetry used for?
Photogrammetry has roots as far back as the mid-19th century when it was used to create topographic maps. For much of its history, photogrammetry has been used in surveying, archaeology, mining, and other industries relying on geospatial data.

With the rise of immersive media and higher quality camera equipment, digital creators are now using photogrammetry to produce copies of static real-world objects, structures, and 3D immersive environments.

How does photogrammetry software work?
Photogrammetry software extracts information (e.g., distance, area, and elevation) from 2D photo inputs. By analyzing the overlapping images taken from various angles, photogrammetry software creates a point cloud, a collection of data points that define an object’s shape.

Point clouds become denser and transform into 3D meshes. Think of a 3D mesh as the structure or basis of a 3D model.3D Model Mesh

After creating a 3D model, artists and designers can optimize, enhance, and edit the model for movies, video games, architecture, and various other projects. Depending on the intended project outcome and workflow, this process can include different pieces of specialized software.

How do I get started with photogrammetry?
Photogrammetry can require very little equipment to get started. A camera (a smartphone will also work), PC or Mac, photogrammetry processing software, and 3D editing software is enough to begin. Additional equipment such as lighting, filters, and lenses could also be necessary depending on what you’re capturing, where you’re capturing it, and when you plan to capture it.

For a more detailed equipment list, see this document by Unity.

Beginner photogrammetry tutorials

Photogrammetry tips and workflows
An oversimplified photogrammetry workflow can be broken down into two main parts. Please note that it’s difficult to pin down a straightforward photogrammetry workflow. Much of the process depends on the object you’re capturing, how you plan to use the digitized item, what software you plan to use, and more.

  1. Capturing: The first step with photogrammetry is to capture the object from various overlapping angles accurately. Ask your self –
    • What am I capturing, and how will it be used in the final project? Moving, shiny or reflective objects can be challenging to capture successfully.
    • Where will I be capturing? Look for a quiet space with a large enough area to capture your subject.
    • When will I be capturing? Environmental factors like wind, rain, and snow can cause movement or reflections. Harsh sunlight can produce strong shadows and hotspots, slowing down the editing process.
  2. Processing: After you’ve reconstructed your object, post-processing often involves mesh generation, optimization, color correction, manual edits, visualization, and more.

Examples of photogrammetry
Artists and creators often use visual mediums such as Sketchfab, YouTube, and Instagram to share examples of their photogrammetry work. The examples below are outstanding.

    • Global Digital Heritage is a research organization that documents cultural heritage with 3D virtualization, geospatial informatics, and 3D models. Their examples are well done, and all their data is publicly available.

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