Many people know the problem: You would like to order something from a webshop, but the available pictures do not sufficiently represent the product and the videos take too long to load. Intuitive operation as well as the ability to view and zoom from various angles translate into demand for 3D web visualization. Max Limper has taken up the topic of automatic optimization of 3D visualization in his dissertation – and has good news for webshop operators and other user groups like game engines.

3D scanning models are ideal for three-dimensional viewing on the Web, but websites and devices like AR glasses often specify a maximum number of polygons. The density of polygons in a 3D scan is indicative of the resolution: The higher the number of polygons, the more detailed the result – and the higher the number of bytes. To minimize the number of bytes for use on the Web, Limper researched a process that fully automatically reduces and recreates the mesh generated by the polygons without sacrificing quality to the human eye. High-quality UV layouts and texture maps are also automatically generated. The model can be exported using increasingly popular 3D viewers like HTML5 and WebGL, or even glTF. This complex process was previously only possible manually.

The core of the work are algorithms of 3D geometry processing for the fully automatic optimization of 3D mesh data, which includes the two areas of mesh simplification and texturing. In this context, a new method for determining local saliency in terms of mesh simplification and a method for automatically eliminating the overlaps of parameterizations will be presented. The result is an approach to densify texture atlases based on repeated cutting and packing operations.

The second part of the dissertation deals with the design of an optimized format for 3D mesh data on the Web. Numerous relevant aspects such as the efficient coding of mesh geometry and topology, a physically based format for material data and the progressive transmission of textured 3D meshes are considered. These examples illustrate how the piecewise progressive streaming of a 3D model works.

The public defense of the dissertation "Automatic Optimization of 3D Mesh Data for Real-Time Online Presentation" took place on May 5 at Fraunhofer IGD in Darmstadt. Advisors were Prof. Dr. med. techn. Dieter W. Fellner (TU Darmstadt) and Prof. Dr. med. Marc Alexa (TU Berlin).