Abstract: In particular embodiments, a computing system may divide at least a portion of a physical space surrounding a user into a plurality of three-dimensional (3D) regions, wherein each of the 3D regions is associated with an area of a plurality of areas in a plane. The system may generate estimated locations of features of objects in the portion of the physical space. Based on the estimated locations, the system may determine an occupancy state of each of the plurality of 3D regions. Then based on the occupancy states of the plurality of 3D regions, the system may determine that one or more of the plurality of areas have respective airspaces that are likely unoccupied by objects.

Abstract: In one embodiment, a method includes segmenting a layout of a physical space surrounding a user into physical segments; generating, based on the physical segments, virtual paths for a virtual environment through which the user can navigate by traveling the physical segments; identifying, based on a current location of the user with respect to the physical space, a portion of the physical segments for which to enable an intrusion detection feature; detecting a physical object in the portion of the physical segments that corresponds to a particular virtual path of the virtual paths; and in response to the detecting, displaying a representation of the physical object in the particular virtual path.

Abstract: In particular embodiments, a computing system may divide at least a portion of a physical space surrounding a user into a plurality of three-dimensional (3D) regions, wherein each of the 3D regions is associated with an area of a plurality of areas in a plane. The system may generate estimated locations of features of objects in the portion of the physical space. Based on the estimated locations, the system may determine an occupancy state of each of the plurality of 3D regions. Then based on the occupancy states of the plurality of 3D regions, the system may determine that one or more of the plurality of areas have respective airspaces that are likely unoccupied by objects.

Abstract: In particular embodiments, a computing system may divide at least a portion of a physical space surrounding a user into a plurality of three-dimensional (3D) regions, wherein each of the 3D regions is associated with an area of a plurality of areas in a plane. The system may generate estimated locations of features of objects in the portion of the physical space. Based on the estimated locations, the system may determine an occupancy state of each of the plurality of 3D regions. Then based on the occupancy states of the plurality of 3D regions, the system may determine that one or more of the plurality of areas have respective airspaces that are likely unoccupied by objects.

Abstract: In one embodiment for generating passthrough, a computing system may access images of an environment captured by cameras of a device worn by a user. The system may generate, based on the images, depth measurements of objects in the environment. The system may generate a mesh covering a field of view of the user and then update the mesh based on the depth measurements to represent a contour of the objects in the environment. The system may determine a first viewpoint of a first eye of the user and render a first output image based on the first viewpoint and the updated mesh. The system may then display the first output image on a first display of the device, the first display being configured to be viewed by the first eye of the user.

Abstract: In one embodiment, a method includes accessing a plurality of points, wherein each point (1) corresponds to a spatial location associated with an observed feature of a physical environment and (2) is associated with a patch representing the observed feature, determining a density associated with each of the plurality of points based on the spatial locations of the plurality of points, scaling the patch associated with each of the plurality of points based on the density associated with the point, and reconstructing a scene of the physical environment based on at least the scaled patches.

Abstract: In one embodiment, a method includes segmenting a layout of a physical space surrounding a user into physical segments; generating, based on the physical segments, virtual paths for a virtual environment through which the user can navigate by traveling the physical segments; identifying, based on a current location of the user with respect to the physical space, a portion of the physical segments for which to enable an intrusion detection feature; detecting a physical object in the portion of the physical segments that corresponds to a particular virtual path of the virtual paths; and in response to the detecting, displaying a representation of the physical object in the particular virtual path.

Abstract: In one embodiment, a method includes segmenting a layout of a physical space surrounding a user into physical segments; generating, based on the physical segments, virtual paths for a virtual environment through which the user can navigate by traveling the physical segments; displaying a particular virtual path based on a location of the user in the virtual environment; determining that a forward direction of travel of the user is proximate to a boundary condition of a particular physical segment corresponding to the particular virtual path; notifying the user that a physical rotation of the user is needed in order for the user to travel beyond a point in the particular virtual path; and detecting that the physical rotation of the user is complete, and in response, updating the display to show the particular virtual path and allowing the user to travel beyond the point in the particular virtual path.

Abstract: In particular embodiments, a computing system may divide at least a portion of a physical space surrounding a user into a plurality of three-dimensional (3D) regions, wherein each of the 3D regions is associated with an area of a plurality of areas in a plane. The system may generate estimated locations of features of objects in the portion of the physical space. Based on the estimated locations, the system may determine an occupancy state of each of the plurality of 3D regions. Then based on the occupancy states of the plurality of 3D regions, the system may determine that one or more of the plurality of areas have respective airspaces that are likely unoccupied by objects.

Abstract: There is disclosed an aircraft wing rib comprising a structural rib section to which a wing skin can be attached; and a suction conduit to which, in use, a negative pressure can be applied so as to cause air to be drawn through suction holes provided in the outer surface of the wing skin. There is also disclosed an aircraft wing including such a wing rib.

Abstract: There is disclosed an aircraft wing rib comprising a structural rib section to which a wing skin can be attached; and a suction conduit to which, in use, a negative pressure can be applied so as to cause air to be drawn through suction holes provided in the outer surface of the wing skin. There is also disclosed an aircraft wing including such a wing rib.

Abstract: An axe sharpening device which comprises an adjustable two piece axe-clamping element having on the upper part thereof a file guide including a base oscillatably mounted on the upper part of the axe clamp with an upper part pivoted thereto and fitted with clamping means holding the file against a pivot pin. Resilient strips are provided on the axe clamping element to securely engage the axe head and to prevent it from slipping.