To demonstrate to my students the power of 3-D scanning on mobile devices compared to conventional and traditional methods such as hand-drawing for recording archaeological features, I scanned the entire lecture hall in advance of a class within 3 minutes using an iPad Pro and the [3D Scanner App](https://3dscannerapp.com), which they used for the class afterwards. Processing the model took another minute, as did uploading it to Sketchfab - 5 minutes for a complete 3D model (albeit done somewhat uncharitably...).