View-dependent refinement of progressive meshes
ACM SIGGRAPH 1997 Proceedings, 189-198.
Lossless multiresolution structure for incremental local refinement/coarsening.
Level-of-detail (LOD) representations are an important tool for real-time rendering of complex geometric
environments. The previously introduced progressive mesh representation defines for an arbitrary
triangle mesh a sequence of approximating meshes optimized for view-independent LOD. In this paper, we
introduce a framework for selectively refining an arbitrary progressive mesh according to changing view
parameters. We define efficient refinement criteria based on the view frustum, surface orientation, and
screen-space geometric error, and develop a real-time algorithm for incrementally refining and coarsening
the mesh according to these criteria. The algorithm exploits view coherence, supports frame rate
regulation, and is found to require less than 15% of total frame time on a graphics workstation. Moreover,
for continuous motions this work can be amortized over consecutive frames. In addition, smooth visual
transitions (geomorphs) can be constructed between any two selectively refined meshes.
A number of
previous schemes create view-dependent LOD meshes for height fields (e.g. terrains) and parametric surfaces
(e.g. NURBS). Our framework also performs well for these special cases. Notably, the absence of a rigid
subdivision structure allows more accurate approximations than with existing schemes. We include results
for these cases as well as for general meshes.