Abstract: Various implementations disclosed herein include devices and methods that obtain and/or maintain a version of a 3D representation of a user's environment and provide limited access to the 3D representation to apps executing on the devices. This may involve providing changed versions of a 3D representation that obfuscate details of the 3D representation from which the apps would otherwise be able to determine or infer private information about the user and/or their physical environment. Versions of the 3D representation provided to one or more apps may be changed in various ways to make it difficult or impossible for an app to uniquely identify a user or their physical environment and/or make it difficult or impossible to determine private information about the user and/or the physical environment.

Abstract: Various implementations disclosed herein include devices, systems, and methods that provide realistic acoustic simulation for sound from a virtual source based on a site specific 3D acoustic model of a physical environment. Some implementations obtain first sensor data representing at least a portion of a first boundary of a physical environment while second sensor data corresponding to a second boundary of the physical environment is absent from the first sensor data. In some implementations, the second boundary of the physical environment is estimated based on the first sensor data. Then, a 3D acoustic model representing the physical environment is determined, where the 3D acoustic model includes a 3D shape formed of at least the first boundary and the second boundary. In some implementations, acoustics are provided for sound from a virtual source corresponding to a position within the physical environment, where the acoustics are provided based the 3D acoustic model.

Abstract: Various implementations disclosed herein include devices, systems, and methods that refine a first 3D surface representation (e.g., a 3D point cloud or a 3D mesh) using a second 3D surface representation that includes a 3D geometric primitive. In some implementations, a first 3D surface representation of a physical environment is obtained including points at 3D locations determined based on data generated by a first sensor. In some implementations, a second 3D surface representation corresponding to at least a portion of the physical environment is obtained that includes at least one 3D geometric primitive. In some implementations, a determination whether to adjust the 3D locations of at least one point of the points of the first 3D surface representation is made based on the 3D geometric primitive, and the 3D locations of the at least one point is adjusted to align with the geometric primitive based on the determination.