In this chapter, we present distance mapping, a technique for adding small-scale displacement mapping to objects in a pixel shader. We treat displacement mapping as a ray-tracing problem, beginning with texture coordinates on the base surface and calculating texture coordinates where the viewing ray intersects the displaced surface. For this purpose, we precompute a three-dimensional distance m...

Touch technology is rapidly evolving, and soon deformable, movable and malleable touch interfaces may be part of everyday computing. While there has been a lot of work on understanding touch interactions on flat surfaces, as well as recent work about pointing on curved surfaces, little is known about how surface deformation affects touch interactions. This paper presents the study of how differ...

Implicit surface blends can be obtained by combining distance surfaces. These are surfaces defined by distance to ‘skeletal’ elements such as points, line segments, polygons, or any free-form curve, surface, or volume. To illustrate, we consider distance to the planar curve shown below. Computing this distance is demanding [Bloomenthal 1989], [Schneider 1990], and often a piecewise linear appro...

    Introduction: In the last few decades, a lot of monte carlo codes have been introduced for medical applications. For close - to - surface tumors, the surface of the skin can be used to increase the surface dose so that all or part of the bunch area can fall into bolus, thereby increasing the dose of the skin. The air gaps between bolus and skin can affect the dose of...

We present an algorithm for computing the distance between two free-form surfaces. Using line geometry, the distance computation is reformulated as a simple instance of a surface-surface intersection problem, which leads to lowdimensional root finding in a system of equations. This approach produces an efficient algorithm for computing the distance between two ellipsoids, where the problem is r...

This paper presents an algorithm for computing the distance between two free-form surfaces. Using line geometry, the distance computation is reformulated as a simple instance of a surface-surface intersection problem, which leads to a low-dimensional root finding in a system of equations. This approach produces an efficient algorithm for computing the distance between two ellipsoids, where the ...

Investigation of the conformational properties of a SAW polymer chain near an impenetrable, non-interacting flat surface showed that the chain at first contracted and orientated itself to slightly parallel when it pulled close to the surface and at last elongated and reoriented itself to slightly perpendicular to the surface at very small distance from the surface. Simulation showed that most o...

Re-distancing the implicit surface is time-consuming. We propose a fast implementation of the Chamfer distance which maintains the sub-voxel accuracy of the interface. This approximation to the Euclidean distance gives a reasonable accuracy while improving considerably the computation time.

Currently, the viability of infrared (IR) as an accurate means of measuring distance depends on extensive prior knowledge of the surface. More speci cally, the manner in which a surface scatters, re ects, and absorbs infrared energy is needed to interpret the sensor output as a distance measure. In order to use IR in an unknown environment, one must determine the surface properties during robot...