Previously, a computationally efficient and geometrically accurate etching simulation was developed to compute contours of constant depth at different time steps [1]. Experimental verification of this early work has been established [2]. However, contours are not amenable to the analysis and design of microsystems, since it is often necessary to determine object interaction and mechanics in whi...

Acceleration structures reducing the number of intersection tests are crucial for high ray tracing performance. The best acceleration structures are currently obtained using the surface area heuristic (SAH) which greedily optimizes a cost metric based on a series of heuristic assumptions about the rays. Noting that rays in many cases originate within the scene’s bounding box, we assume a unifor...

Subdivision Surfaces as well as (interactive) ray tracing have become an important issue in computer graphics. But ray tracing of subdivision surfaces has received only little attention. We present a new approach for ray tracing of subdivision surfaces. The algorithm uses a projection of the ray onto the surface and works mainly in two dimensions along this projection. While proceeding from pat...

We present a new approach to finding ray–patch intersections with triangular Bernstein–Bézier patches of arbitrary degree. This paper extends and complements on the short presentation 17. Unlike a previous approach which was based on a combination of hierarchical subdivision and a Newton–like iteration scheme 21, this work adapts the concept of Bézier clipping to the triangular domain. The prob...

In this paper we present a general technique for real-time display of very large models. We combine methods for culling and level-ofdetail management with wire-frame representations, generated dynamically from a hierarchy of bounding volumes. Smoothly moving boundary planes ensure that changes of representation do not lead to distracting popping effects. Context-sensitive landmark objects are a...

Visual coverage is one of the most important quality indexes for depicting the usability of an individual camera or camera network. It is the basis for camera network deployment, placement, coverage-enhancement, planning, etc. Precision and efficiency are critical influences on applications, especially those involving several cameras. This paper proposes a new method to efficiently estimate sup...

Distance bounding protocols enable a device to establish an upper bound on the physical distance to a communication partner so as to prevent location spoofing, as exploited by relay attacks. Recently, Rasmussen and Čapkun (ACM-CCS’08) observed that these protocols leak information on the location of the parties to external observers, which is undesirable in a number of applications—for example ...

Derivatives and normals of rational Bézier curves and surface patches are discussed. A nonuniformly scaled hodograph of a degree m × n tensor-product rational surface, which provides correct derivative direction but not magnitude, can be written as a degree (2m−2) × 2n or 2m× (2n−2) vector function in polynomial Bézier form. Likewise, the scaled normal direction is degree (3m−2)× (3n−2). Effici...

We give a new proof of the theorem of Birman–Powell that the Torelli subgroup of the mapping class group of a closed orientable surface of genus at least 3 is generated by simple homeomorphisms known as bounding pair maps. The key ingredient is a proof that the subcomplex of the curve complex of the surface spanned by curves within a fixed homology class is connected.

The geodesic flow of any Riemannian metric on a geodesically convex surface of negative Euler characteristic is shown to be semi-equivalent to that of any hyperbolic metric on a homeomorphic surface for which the boundary (if any) is geodesic. This has interesting corollaries. For example, it implies chaotic dynamics for geodesic flows on a torus with a simple contractible closed geodesic, and ...