This paper proposes a novel approach for automatically generating accurate floor plans and 3D models of building interiors using scanned mesh data. Unlike previous methods, which begin with a high resolution point cloud from a laser range-finder, our approach begins with triangle mesh data, such as from a Microsoft HoloLens headset. The approach includes generating two types of floor plans, a "pen-and-ink" style that preserves details and a drafting-style that reduces clutter, and processing the 3D model for use in applications by aligning it with coordinate axes, annotating important objects, dividing it into stories, and removing the ceiling. The performance of each step is analyzed on commercial and residential buildings, and experiments are conducted to evaluate the appearance of results when different amounts of transparency and numbers of mesh slices are used. Our approach has applications in navigation, interior design, furniture placement, facilities management, building construction, and heating, ventilation, and air conditioning (HVAC) design. In general, our approach appears to be promising for automatic digitization and orientation of scanned mesh data for floor plan and 3D model generation.