Calibration and viewpoint consistent modelling of BTF data

Visual effects play an important role in the film and game industry, In both, the observer immerses into a virtual world which comes already amazingly close to the real world. One approach is to collect parts of the real world and reassamble them at will. When following this approach for complicated surface materials, the material must be recorded for many different viewing and illumination conditions leading to so-called BTF data sets. However, the raw recordings must first be processed before being used in computer graphical applications. In this thesis, we first work on the calibration of BTF setups. The goal is a calibration procedure which is based on the recorded BTF data sets in order to simplify the usage of BTF setups. Even though today's BTF setups are not designed for transportation, portable setups are planned, such that for instance archeological objects can be recorded on site. The recalibration, which is necessary after each transportation of a setup, can be performed by the proposed methods with low effort. Although the calibration provides the conditions under which the material has been recorded, it is still a long way to its integration into a virtual world. When for instance a virtual wall should imitate the appearance of stone, the recorded piece of stone is far too small for this task. However, synthesis algorithms can take the recorded BTF data as an example and generate larger, visually similar pieces. Furthermore, it should be possible to render the synthetic material correctly, when viewpoint and illumination are changing. For it, the material must be described by a viewpoint consistent model which supports the synthesis task. In the second part, we discuss the complete pipeline from the raw input to the visualization of synthetic output for different models. For the occurring problems, we present general solution strategies.