Constructing a 3D model of a facility based on video streams from cameras at the facility

A 3D modeling service of a provider network may receive, from a client facility, different video streams from different cameras at the facility (e.g., security cameras). The 3D modeling service may generate a collection of image data based on the different video streams. The 3D modeling service may construct a 3D model of the facility based at least on the collection of image data and other data from one or more other sources (e.g., CAD files other floor plans). The 3D model may be analyzed to determine various aspects, such as a location to place equipment or coverage gaps of the security cameras. Facility management may perform various actions based on updated 3D models. For example, equipment may be installed at a location or cameras may be installed to eliminate coverage gaps.