Spatial mapping and 3D reconstruction in augmented reality
Spatial mapping and 3D reconstruction are augmented reality (AR) techniques used to understand and interact with the surrounding world. They create digital representations of the physical world, allowing virtual objects to be embedded and emulated in the real world.
Spatial mapping
Spatial mapping, also known as environmental mapping or spatial perception, refers to capturing and analyzing the properties of the physical environment in real-time. It involves using various sensors such as cameras, depth sensors, or LiDAR (light detection and ranging) to gather information about the shape, position, and relationship of the objects in the world. This technique creates a three-dimensional (3D) map or model of the environment and uses that model according to our needs.
The above slide shows a developed application demo of an AR app in Unity to identify the horizontal plane (floor/any horizontal space) and place an object anywhere we touch on the detected plane. We can further change the object and place wherever we like in the environment. This is only one of the simple examples of spatial mapping.
3D reconstruction
3D reconstruction focuses on creating a detailed and accurate representation of real-world objects or events. It involves capturing multiple images of an object or scene from various angles and using computer vision algorithms to combine those images into a cohesive 3D model. The process will include depth estimation, feature extraction, and a matching process to determine shape, structure, and texture.
The slide above shows a demo of a 3D-construction-based AR application to map and construct filters on real face images. We can change and apply these filters on any face in a real environment.
3D reconstruction and spatial mapping applications in AR
Here are some applications of 3D reconstruction and Spatial mapping.
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Object placement and interaction: Spatial mapping allows AR systems to understand the geometry and surfaces of the real-world environment. This enables accurate placement of virtual objects onto physical surfaces, such as tables, floors, or walls. Users can interact with these virtual objects, move them around, and manipulate them within the real world.
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Occlusion and realism: Spatial mapping helps create realistic occlusion effects in AR. Virtual objects can be hidden or occluded by real-world objects, providing a more immersive and believable experience. For example, a virtual character can appear behind a table or a virtual object hidden behind a physical wall.
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Environmental understanding: Spatial mapping enables AR systems to understand the layout and structure of the environment. This understanding can be used for various purposes, such as navigation assistance, indoor mapping, or architectural visualization. AR applications can overlay information or virtual guidance onto the real environment based on spatial mapping data.
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Gaming and entertainment: Spatial mapping and 3D reconstruction are extensively used in AR gaming and entertainment applications. Virtual objects or characters can be placed and interacted with in the real world, creating immersive and interactive gaming experiences. For example, players can fight virtual monsters appearing in their living room or play virtual sports in their backyard.
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Design and visualization: Architects, industrial designers, and product developers can use AR spatial mapping and 3D reconstruction to visualize and assess designs in a real-world context. They can overlay virtual prototypes onto physical spaces, evaluate the aesthetics and functionality, and make real-time modifications.
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Education and training: Spatial mapping and 3D reconstruction enhance educational and training experiences. Students can explore virtual models of complex structures or historical sites overlaid in the real environment. AR can also simulate training scenarios, such as medical procedures or industrial equipment operations, with virtual objects interacting realistically with the real-world environment.
In augmented reality applications, spatial mapping and 3D reconstruction facilitate virtual objects' interaction with the physical world. By understanding the geometry and layout of the environment, AR systems can accurately place virtual objects on surfaces, align them with real-world objects, and provide realistic occlusion effects, where virtual objects can be hidden behind real objects.
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