3D and 4D modeling for AR and VR app developments

The design of three-dimensional and four-dimensional Apps, running on the leading operating systems Android, iOS and Windows is the next challenge in Architecture, BIM, Civil Engineering, Digital Cultural Heritage (DCH) preservations and many more. Based on experiences developing Apps for archaeology and architecture, the paper introduces with general workflows for 3D data collection, using laser scanning, geometric computer vision and photogrammetry. The resulting point clouds have to be merged, using the most recent developments of laser scanning, computer vision, photogrammetry and statistical inference. 3D and 4D modeling is done using professional software from surveying and computer graphics, such as Leica's Cyclone, Trimble's SketchUp and Autodesk 3ds Max. The fourth dimension, time, is injected onto the 3D contemporary models using the texture of old photos. After homogenization of all 3D models in Autodesk 3ds Max these are exported to the game engine Unity to allow for the creation of the reference surface and finally the 3D urban model. The storyboard creates for the programmer an outline, which features and functions have to be fulfilled. Finally the Apps for Android, iOS and Windows are created and exported for the use on mobile devices.