Fat Borders: Gap Filling For Efficient View-dependent LOD Rendering

Real-time high quality rendering of complex models remains a big challenge. Simply splitting the models into several parts which can be simplified and rendered independently introduces disturbing gaps along the common borders. Recent approaches for viewdependent rendering of huge models either neglect the artifacts introduced by the gaps or try to maintain the connectivity of the models. Unfortunately, in the second case the computational complexity and storage requirements of the algorithms are tremendous. In this work we present a novel solution to the gap problem. Vertex programs are used to generate appropriately shaded fat lines that fill the gaps between neighbouring patches. Based on our method the development of new algorithms for out-of-core simplification and view-dependent rendering of complex triangle meshes is straightforward. Due to its generality, simplicity and effectiveness our method has the potential of becoming part of future graphics APIs. To demonstrate the capabilities of our method we apply our new algorithm to the rendering of complex trimmed NURBS models, where the gap problem becomes especially apparent as these models consist already of thousands of independent trimmed patches. Combining the new gap filling algorithm with an on-the-fly tessellation of the individual trimmed NURBS patches we are able to visualize deformable trimmed NURBS models with dynamic neighbourhood in real-time. CR Categories: I.3.3 [COMPUTER GRAPHICS]: Picture/Image Generation—Display algorithms; I.3.7 [COMPUTER GRAPHICS]: Three-Dimensional Graphics and Realism—Animation