A clear explanation of spatial anchors for AR
Spatial anchors are fixed reference points that allow digital content to stay in the same physical location in the real world. They link virtual content to physical space so that it feels stable, persistent and reliably placed.
A spatial anchor is created based on computer vision and sensors scanning your environment. Systems like SLAM, World tracking and Plane detection collect visual features, depth information and motion data about your space. The device then uses these features to establish relative position and a virtual coordinate system. With this information, the device establishes an anchor's origin, which allows the 3D model and content to stay locked within a consistent physical location.
Anchors rely on feature points. These are small areas of high contrast in the environment that the system can reliably recognize. As a person moves, the device watches how these points shift and uses 6DoF motion to adjust the anchor's position frame by frame. Depth data from LiDAR or a Depth Sensor helps to refine these anchors by understanding the world's geometry.
Spatial anchors make AR content feel believable and consistent. They allow virtual objects to stay in the same place when you move around or when you leave and come back later. This is persistence and AR localization.
It turns augmented reality from a momentary effect to something that you can revisit at any time. It also enables shared experiences where multiple people can see the same content aligned in the same physical location.
Anchors create the foundation for long-term spatial layouts. Ideally, persistent objects can remain stable over days, weeks, or years. They could be signage, instructions, art, or any digital content. This spatial consistency is necessary for a larger vision of the spatial internet, where information is placed in the world instead of on screens. Anchors also prevent drift. Without them, content could slide, float, or jitter around. With them, digital objects behave like part of the room. Good anchors support occlusion, collision, and accurate scale, making interactions feel intuitive and grounded in reality.
Designers should build around anchor reliability. Your space won't always have perfect anchors, so choose anchor methods that match your environment. Avoid reflective materials and repeating patterns, and keep your AR content within a reasonable distance to the anchor itself. In Trace, your content should be within a 20 meter radius of an image anchor for best results.
Once you set up an image anchor in Trace, all you have to do is place your content around the space, and location, position, and scale will be remembered automatically. Creating an image marker that's easy to recognize allows visitors to discover that and your AR content quickly and easily. We can also add QR codes to our anchors so visitors can simultaneously open the app, find the experience, and localize within a space.
• A graphic label that is pasted ona piece of machinery. This act as an image anchor to let digital instructions appear consistently for trainees.
• A prominent framed painting that acts as an anchor for the whole gallery. Digital images and sculptures appear in the room around the painting.
• A pamphlet for a science museum that a visitor takes home. This acts as an ‘anywhere’ anchor that pops up a 3D solar system whenever a visitor scans the pamphlet.
• Anchors do not require perfect meshes. They need consistent feature points.
• Image anchors are not easily recognized on reflective objects or vector based graphics. Raster images with dense texture perform best.
• You do not need a QR code for an image anchor. A graphic, like a poster, can serve as your image anchor, whereas a QR code allows visitors to open your app and see your project. You can combine these into one graphic to serve both purposes.
Spatial anchors are essential for persistent augmented reality. They help digital content stay grounded, stable, and persistent within your space. When anchors are well made, AR becomes something that visitors can return to instead of a fleeting effect.
Learn about augmented reality or start creating your own experiences.
