INTERACTING WITH 3D PHOTOREALISTIC OUTCROP MODELS USING AN iPAD

A systematic workflow utilizing an Apple iPad allows a user to interact with 3-D photorealistic outcrop models by manually tracing geological features on 2-D distortion-free images. The application can be used in the field, in front of the outcrop or in front of 3D model in the lab or classroom. A readily available iPad applet is coupled with a MatLab script to perform coordinate transformations which facilitate 3-D geological analysis. The essence of the photorealistic modeling process developed at UTD is the rigorous and accurate registration of digital image pixels onto a 3-D surface model. The surface model depends on the integration of various combinations GPS, total station, laser scanner and photogrammetric data. Curves traced in 2-D on images displayed on the iPad are transformed into three dimensions using a six parameter transformation developed in the model building process. Subsequently, geological features can be attributed, annotated, quantitatively analyzed (strikes, dips, etc.) and visualized. UTD, as well as other groups, have been creating such 3-D models since 1998. The approach described here can be used on any photorealistic model based on the correlation between imagery and 3-D geometry. Various types of commercial software have also been used to digitize and extract information from such models in industrial and academic applications, but this is an alternative complementary approach. The background computations taking place are transparent to the user, and therefore can be readily used at many different levels from academia to industry. The tablet’s portability and cost effectiveness ensures a wide range of potential users. In this configuration, the workflow allows participants in different locations to communicate in real time through the internet. Case studies will be presented in research, and in both graduate and undergraduate education. Similar applications can be built on Android tablets.