This paper surveys the field of augmented reality AR, in which 3D virtual objects are integrated into a 3D real environment in real time. It describes the medical, manufacturing, visualization, path planning, entertainment, and military applications that have been explored. This paper describes the characteristics of augmented reality systems, including a detailed discussion of the tradeoffs between optical and video blending approaches. Registration and sensing errors are two of the biggest problems in building effective augmented reality systems, so this paper summarizes current efforts to overcome these problems. Future directions and areas requiring further research are discussed. This survey provides a starting point for anyone interested in researching or using augmented reality.

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A survey of augmented reality

Planning algorithms are impacting technical disciplines and industries around the world, including robotics, computer-aided design, manufacturing, computer graphics, aerospace applications, drug design, and protein folding. This coherent and comprehensive book unifies material from several sources, including robotics, control theory, artificial intelligence, and algorithms. The treatment is centered on robot motion planning but integrates material on planning in discrete spaces. A major part of the book is devoted to planning under uncertainty, including decision theory, Markov decision processes, and information spaces, which are the “configuration spaces” of all sensor-based planning problems. The last part of the book delves into planning under differential constraints that arise when automating the motions of virtually any mechanical system. Developed from courses taught by the author, the book is intended for students, engineers, and researchers in robotics, artificial intelligence, and control theory as well as computer graphics, algorithms, and computational biology.

Planning Algorithms: Introductory Material

An introduction to the Kalman filter

A simple and efficient randomized algorithm is presented for solving single-query path planning problems in high-dimensional configuration spaces. The method works by incrementally building two rapidly-exploring random trees (RRTs) rooted at the start and the goal configurations. The trees each explore space around them and also advance towards each other through, the use of a simple greedy heuristic. Although originally designed to plan motions for a human arm (modeled as a 7-DOF kinematic chain) for the automatic graphic animation of collision-free grasping and manipulation tasks, the algorithm has been successfully applied to a variety of path planning problems. Computed examples include generating collision-free motions for rigid objects in 2D and 3D, and collision-free manipulation motions for a 6-DOF PUMA arm in a 3D workspace. Some basic theoretical analysis is also presented.

/pdf/rrt-connect-an-efficient-approach-to-single-query-path-o9jeu33wyv.pdf

RRT-connect: An efficient approach to single-query path planning

In 1960, R.E. Kalman published his famous paper describing a recursive solution to the discrete-data linear filtering problem. Since that time, due in large part to advances in digital computing, the Kalman filter has been the subject of extensive research and application, particularly in the area of autonomous or assisted navigation. The Kalman filter is a set of mathematical equations that provides an efficient computational (recursive) means to estimate the state of a process, in a way that minimizes the mean of the squared error. The filter is very powerful in several aspects: it supports estimations of past, present, and even future states, and it can do so even when the precise nature of the modeled system is unknown. The purpose of this paper is to provide a practical introduction to the discrete Kalman filter. This introduction includes a description and some discussion of the basic discrete Kalman filter, a derivation, description and some discussion of the extended Kalman filter, and a relatively simple (tangible) example with real numbers & results.

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An Introduction to the Kalman Filter

We present a data structure and an algorithm for efficient and exact interference detection amongst complex models undergoing rigid motion. The algorithm is applicable to all general polygonal models. It pre-computes a hierarchical representation of models using tight-fitting oriented bounding box trees (OBBTrees). At runtime, the algorithm traverses two such trees and tests for overlaps between oriented bounding boxes based on a separating axis theorem, which takes less than 200 operations in practice. It has been implemented and we compare its performance with other hierarchical data structures. In particular, it can robustly and accurately detect all the contacts between large complex geometries composed of hundreds of thousands of polygons at interactive rates. CR

/pdf/obbtree-a-hierarchical-structure-for-rapid-interference-377ihhq344.pdf

OBBTree: a hierarchical structure for rapid interference detection

We present new distance computation algorithms using hierarchies of rectangular swept spheres. Each bounding volume of the tree is described as the Minkowski sum of a rectangle and a sphere, and fits tightly to the underlying geometry. We present accurate and efficient algorithms to build the hierarchies and perform distance queries between the bounding volumes. We also present traversal techniques for accelerating distance queries using coherence and priority directed search. These algorithms have been used to perform proximity queries for applications including virtual prototyping, dynamic simulation, and motion planning on complex models. As compared to earlier algorithms based on bounding volume hierarchies for separation distance and approximate distance computation, our algorithms have achieved significant speedups on many benchmarks.

/pdf/fast-distance-queries-with-rectangular-swept-sphere-volumes-5ckrp6tdbp.pdf

Fast distance queries with rectangular swept sphere volumes

Collision detection is essential for many applications involving simulation, behavior and animation. However, it has been regarded as a computationallydemanding task and is often treated as an advanced feature. Most commonly used commercial CAD/CAM packages and high performance graphics libraries, such as SGI Performer, provide limited support for collision detection. As users continue to stretch the capabilities of VRML, collision detection will soon become an indispensable capability for many applications. In this paper, we present a system for accelerated and robust collision detection and describe its interface to VRML browsers. We demonstrate that it is possible to perform accurate collision detection at interactive rates in VRML environments composed of large numbers of complex moving objects. CR

/pdf/v-collide-accelerated-collision-detection-for-vrml-4bkurnfbqt.pdf

V-COLLIDE: accelerated collision detection for VRML

Bounding volume hierarchies (BVHs) have been used widely in collision detection algorithms. The most commonly used bounding volume types are axis-aligned bounding boxes (AABBs) and spheres, which have simple representations, compact storage, and are easy to implement. This dissertation explores the use of oriented bounding boxes (OBBs), which may be aligned with the underlying geometry to fit more tightly. We believe that OBBs historically have been used less often because previously known methods for testing OBBs for overlap were relatively expensive, good methods for automatic construction of trees of OBBs were not known, and the benefits of using OBBs were not well understood. In this dissertation we present methods for building good trees of OBBs and demonstrate their use in efficient collision detection. In particular, we present a new OBB overlap test which is more efficient than previously known methods. We also examine some of the trade-offs of using OBBs by analyzing benchmark results comparing the performances of OBBs, AABBs and spheres, and we show that OBBs can significantly outperform the latter two bounding volumes for important classes of inputs. We also present two new tools, the bounding volume test tree (BVTT) and the contact pair matrix (CPM), for analyzing collision queries. Finally, we describe the design and implementation of a software system that permits the fair comparison of algorithmic variations on BVH-based collision detection.

Collision queries using oriented bounding boxes

An optoelectronic head-tracking system for head-mounted displays is described. The system features a scalable work area that currently measures 10' x 12', a measurement update rate of 20-100 Hz with 20-60 ms of delay, and a resolution specification of 2 mm and 0.2 degrees. The sensors consist of four head-mounted imaging devices that view infrared lightemitting diodes (LEDs) mounted in a 10' x 12' grid of modular 2' x 2' suspended ceiling panels. Photogrammetric techniques allow the head's location to be expressed as a function of the known LED positions and their projected images on the sensors. The work area is scaled by simply adding panels to the ceiling's grid. Discontinuities that occurred when changing working sets of LEDs were reduced by carefully managing all error sources, including LED placement tolerances, and by adopting an overdetermined mathematical model for the computation of head position: space resection by collinearity. The working system was demonstrated in the Tomorrow's Realities gallery at the ACM SIGGRAPH '91 conference. CR categories and subject descriptors: I.3.1 [Computer Graphics]: Hardware Architecture three dimensional displays; I.3.7 [Computer Graphics]: ThreeDimensional Graphics and Realism Virtual Reality Additional

https://www.ronaldazuma.com/papers/cambridge.pdf

Stefan Gottschalk

Papers

OBBTree: a hierarchical structure for rapid interference detection

Fast distance queries with rectangular swept sphere volumes

V-COLLIDE: accelerated collision detection for VRML

Collision queries using oriented bounding boxes

A demonstrated optical tracker with scalable work area for head-mounted display systems