Virtuelle Realität und physikalisch-basierte Simulation WS 12/13
Virtual Reality (VR) is a research area at the intersection of computer graphics, physically-based simulation, and 3D human-computer interaction (HCI). VR is concerned with novel interaction devices and interaction metaphors in virtual environments (in particular intuitive and direct metaphors), immersion and presence, and real-time rendering. Another important topic is physically-based simulation in real-time, which tries to simulate real-world phenomena such as fire, cloth, the behavior of rigid objects when colliding with each other, fluids, or objects made of deformable material.
Over the past one or two decades, VR has established itself as an important tool in several industries, such as manufacturing (e.g., automotive, airspace, ship building), architecture, and pharmaceutical industries. In addition, a lot of the techniques and solutions developed in the area of VR can be applied directly to computer games.
In this course, we will first look at the fundamental methods, and then go on to more advanced algorithms that are needed to build complex and full-fledged VR systems or real-time computer games. Example topics are object behavior, acoustic rendering, haptics, and collision detection.
The assignments will be mostly practical ones, based on the cross-platform
VR system
InstantReality.
Participants can choose the programming language from
Java, Javascript, and C++.
You are encouraged to work on assignments in small teams.
Some of the topics to be covered (tentatively):
- Introduction, basic notions of VR, a few applications
- VR devices: displays, tracking, input devices, software design
- Stereo rendering
- Error correction: tracking correction, filtering
- Techniques for real-time rendering
- Fundamental immersive interaction techniques: gesture recognition, navigation, selection, grasping, menues in 3D
- Complex immersive interaction techniques: world-in-miniature, action-at-a-distance, magic lens, etc.
- Collision detection
- Force feedback: rendering forces
- Acoustic rendering
- Particle systems
- Spring-mass systems
Note: this list is just tentative and subject to change during the semester.
Aktuelles
Slides
The following table contains all the topics that were covered in this class, the accompanying slides, exercise sheets, and frameworks for solving the programming exeercises. (This table will be filled week by week.)
Note that the German slides are, in some places, slightly out-of-date! The authoritative source are the English slides!
Week | Topics |
---|---|
1. |
Einführung (Definitionen, Immersion, Präsenz, Geschichte), Szenengraphen (Semantik von Knoten und Kanten, multi-threaded VR Applications, verteiltes Rendering, Thread-Safety); |
2. | Fields-and-Routes-Konzept, VRML/X3D (Geometry, Grouping, DEF/USE, behavior graph, events and routes) |
3. | Displays, Advantages/Disadvantages, Stereo Displays, Multiplexing variants for stereo, Multi-User stereo, the Horopter, stereo projection, Issues with stereo projection |
4. | Real-time Rendering: Sources of latency, view-independent rendering, level-of-Detail techniques, predictive LOD selection, progressive meshes, portal culling, image warping |
5. |
Input Devices: degrees of freedom, multimodality, virtual trackball,
tracking, data gloves, locomotion devices Interaction metaphors 1: Universal Interaction Tasks, design of user interfaces, gesture recognition, navigation metaphors (point-and-fly et al.), magic mirror, navidget |
6. | Interaction metaphors 2: user models (power law of practice, Hick's law, Fitts's law), selection techniques, go-go, ray-based techniques, control-display ratio, eye-hand mismatch, cone-based techniques, iSith, balloon selection, action-at-a-distance, image plane interaction, proprioceptive interaction, world-in-miniature, voodoo dolls, magic lenses, system control, menus, marking menus, tanible user interfaces |
7. | Particle Systems: dynamics/kinematics, Euler integration, pahse space, definitions, particle interactions, collision handling, rendering, rendering transparent objects, flames & fire, procedural modeling of plants. |
8. |
Massively-parallel sorting on the GPU with odd-even merge sort. Mass-spring systems: Newton's Laws, single spring-damper, explicit Euler integration, instability and error accumulation with Euler integration, Runge-Kutta, Verlet integration, constraints. |
9. |
Mass-spring systems 2:
Implicit integration, tangent stiffness matrix, comparison to explicit integration,
mesh creation for volumetric objects, consistent collision response for volumetric
mass-spring systems. Haptics 1: applications, devices, the haptic loop, human factors, haptic textures, buzzing, intermediate representations, software architecture. |
10. |
Haptics 2: impendance/admittance approaches, surface contact point approach,
voxmap-pointshell method, friction in one contact point, haptic illusions. Collision detection: importance, definitions, collision detection pipeline, broad/narrow phase, plane-sweep technique, separating planes algorithm (for convex objects), Mikowski sums, intersection test based on Minkowski sums, hierarchical coll.det., bounding volume hierarchies, kinds of BV's, separating axis test (SAT), overlap test for k-DOP's, restricted boxtrees, construction of BVH's. |
Here are some examples and demos of VRML, some of which I have presented in class. You can use them, for instance, to test your VRML client/browser setup.
Literature
- Kay M. Stanney (Ed.): Handbook of Virtual Environments. Lawrence Erlbaum Associates, 2002
- William R. Sherman, Alan B. Craig: Understanding Virtual Reality. Morgan Kaufmann, 200
- Don Brutzman, Leonard Daly: X3D: Extensible 3D Graphics for Web Authors. Morgan Kaufmann, 2007.
- Daniel Fleisch: A Student's Guide to Vectors and Tensors. Cambridge University Press
- Kenny Erleben et al.: Physics Based Animation. Charles River Media, 2005.
- Mario Gutiérrez, Frédéric Vexo, Daniel Thalmann: Stepping into Virtual Reality. Springer, 2008. You can read the e-book from within the university's network.
- Anthony Steed, Manuel Oliveira: Networked Graphics: Building Networked Games and Virtual Environments. Morgan Kaufman, 2009. From this book, only chapters 7, 10, and 11 are relevant to this course.
Warning: these text books can only give you a general introduction to the field of VR! Most of the topics taught in class will not be covered by any of these text books directly -- in fact, AFAIK there are no text books that cover these topics. Therefore, I recommend to attend class.
If you are thinking of buying some of these books, then I suggest to consider buying a used copy of them -- very often, you can find them at a fraction of the price of a new copy. The following are two very good internet sites for finding inexpensive used copies of books: Abebooks and BookButler.
Online Literature and Resources on the Internet
- Tools that can "play" X3D- / VRML97 files:
- InstantReality; on their homepage, you can also find a lot of examples and tutorials.
- FreeWRL (for Linux and OSX).
- Cortona; this is a commercial browser plugin.
- Introduction to VRML / X3D:
- A "Cheat Sheet" for VRML.
- SIGGRAPH 2008 Class Notes: Don't be a WIMP; konkrete Anleitungen, wie spezielle Features in InstantReality benutzt werden (z.B. die verschiedenen Stereo-Modi, Interaktionsgeräte, Clustering, Scripting, Animationen, etc.). (Quelle)
- The Annotated VRML97 Reference Manual (Quelle)
- Der VRML Primer and Tutorial; die Kapitel, die etwas mit HTML zu tun haben, sind für uns nicht relevant, auch ist das Kapitel über Tools völlig veraltet, aber ansonsten immer noch eine brauchbare Einführung für Anfänger (Quelle)
-
Die wichtigsten Dokumente zum X3D-Standard:
- Architecture and base components (d.h., Spec der Knoten und Profiles)
- Scene access interface (SAI)
- X3D language bindings for Javascript (ECMAScript)
- X3D language bindings for Java
- Beispiele für X3D / VRML:
- Die Beispiele aus der Vorlesung (und viele weitere!)
- Auf der Homepage von InstantReality;
- Auf der Homepage des X3D Buches von Don Brutzman und Leonard Daly;
- Eine Meta-Seite mit vielen Links zu großen Archiven von Beispielen.
- Eine große Sammlung von Materialien,
sowohl im VRML- als auch im XML-Encoding.
Und hier das ganze nochmal als ZIP-Archiv. - Links zu sog. "Authoring Tools" gibt es hier; wer mag, kann diese gerne einetzen. Allerdings bezweifle ich den signifikanten Nährwert, da wir alle gut programmieren und mit Text-Editoren umgehen können.
- A handy little tool for Calculating VRML Viewpoints.
- Nicht ganz ernst gemeint sind die Cartoon Laws of Physics ;-) .
- Weiterführende Literatur zum Thema "User Interface Design":
- Das Siggraph 2001 tutorial Advanced Topics in 3D User Interface Design
- Ein unterhaltsames und lehrreiches Quiz zu Fitts' Law
- Eine Erläuterung, wo überall Fitts' Law im UI Design von Office 2007 Anwendung fand: Giving You Fitts
- Literatur zur physikalisch-basierten Simulation allgemein:
- Norman Wittels: Introductory Vector Calculus (Quelle)
- Real Time Physics; Siggraph 2008 course notes.
- Physically Based Modeling; Siggraph 2001 course notes.
- Physically Based Deformable Models in Computer Graphics Andrew Nealen, Mathias Muller, Richard Keiser, Eddy Boxerman and Mark Carlson, EG 2005 (nice survey paper of the field)
- Literatur zu Partikel- und Feder-Masse-systemen:
- William T. Reeves: Particle Systems - A Technique for Modeling a Class of Fuzzy Objects;
- Georgii, Westermann: Mass-Spring Systems on the GPU, Simulation Practice and Theory 2005. (Quelle)
- Die Novelle
Gegen den Strich
von Joris-Karl Huysmans.
Denkanregung: was hat das mit VR zu tun?
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Gabriel ZachmannLast modified: Fri Sep 20 15:16:12 MDT 2013