Multiresolution Displacement Mapping on Subdivision Surfaces
Diploma Thesis concluded at the Bauhaus-University Weimar
Abstract
In computer graphics subdivision surfaces is a technique to create smooth
surfaces out of coarse polyhedral nets. Moreover it is capable of
creating excellent high-density tessellations on todays'
hardware in real-time. Additionally, due to the recursive generation
nature it is also ideally suited for adding geometric detail in
different resolutions.
When modeling real world
surfaces it is possible to use image samples to recover wrinkled
characteristics of a material and apply these on dense discrete meshes
in the form of vertices displacement. Material characteristics are a
mixture of features of different sizes which can be recovered by a
frequency decomposition of an input height map. These sub-bands can be
successively applied on different resolutions of the subdivision
evaluation process in order to achieve naturally looking objects.
Although this can be done in software, the resulting amount
of data and the processing time are prohibitively large. This thesis
presents a method for computing displaced subdivision surfaces on the
GPU that can render overlapping patches of the surface
independently from each other without loss of mesh coherence. Thus,
this method is ideally suited for on-the-fly generation of geometric
detail as demanded by the viewing position of a rendering application.