We describe ERIT, a collection of C routines for efficiently and reliably handling intersection queries between pairs of primitive objects in 3D. ERIT supports intersection queries between the following pairs of primitives: triangle/line-segment, triangle/triangle, sphere/linesegment, sphere/triangle, cylinder/line-segment, cylinder/triangle, cylinder/sphere, cone/linesegment, cone/triangle, toroid/line-segment, toroid/triangle, and sphere/sphere. All intersection routines are based on standard `epsilon-based' floating-point arithmetic. Practical tests have proved that ERIT's routines are efficient and reliable, and we provide performance statistics for three widely-used hardware platforms. The source code for ERIT is available from the author. 1 Introduction 1.1 Motivation and Related Work Checking whether two primitives (e.g., two triangles) intersect in three dimensions (3D) is common in graphics. An implementation should be efficient and reliable. Handling all degenerate cases --...

The ability to perform efficient collision detection is essential in virtual reality environments and their applications, such as walkthroughs. In this paper we re-explore a classical structure used for collision detection -- the binary space partitioning tree. Unlike the common approach, which attributes equal likelihood to each possible query, we assume events that happened in the past are more likely to happen again in the future. This leads us to the definition of self-customized data structures. We report encouraging results obtained while experimenting with this concept in the context of self-customized bsp trees. Keywords: Collision detection, binary space partitioning, self-customization. 1 Introduction Virtual reality refers to the use of computer graphics to simulate physical worlds or to generate synthetic ones, where a user is to feel immersed in the environment to the extent that the user feels as if "objects" seen are really there. For example, "objects" should m...

Detecting whether two geometric objects intersect and computing the region of intersection are fundamental problems in computational geometry. Geometric intersection problems arise naturally in a number of applications. Examples include geometric packing and covering, wire and component layout in VLSI, map overlay