Virtual Reality and Physically-Based Simulation WS 13/14
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
Participants can choose the programming language from
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.
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.)
Introduction (definitions, immersion, fidelity, presence, history),
scenegraphs (semantics of nodes and edges, shared geometry)
|2.||The concept of fields-&-routes, VRML/X3D, geometry, grouping, DEF/USE, behavior graph, events and routes, behavior nodes, event cascades|
|3.||Stereo rendering (human visual system, stereo projection, issues with stereo rendering, user model, image multiplexing, stereo for multiple users, immersive projection technologies)|
|4.||Real-time rendering: sources of latency, view-independent rendering, level-of-detail techniques, predictive LOD selection, progressive meshes, portal culling, state sorting, sorting buffer, image warping|
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, taxonomy, navigation metaphors (point-and-fly et al.), magic mirror, navidget
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, flexible pointer, bent ray,
iSith, bubble cursor, depth ray, balloon selection,
action-at-a-distance, image plane interaction, proprioceptive interaction,
world-in-miniature, voodoo dolls, magic lenses, gimlenses, system control, menus,
marking menus, tangible user interfaces.
Particle systems: dynamics/kinematics, Euler integration, phase space, definition of particle systems,
|8.||Particle systems: physical effects, non-physical effects, collision handling, rendering, rendering transparent objects, flames & fire, procedural modeling of plants, the concept of streaming architectures|
Newton's Laws, single spring-damper, explicit Euler integration, instability
and error accumulation with Euler integration, Runge-Kutta, Verlet integration,
implicit integration, tangent stiffness matrix, comparison to explicit integration,
Haptics: applications, devices, the haptic loop, human factors, haptic textures, buzzing, intermediate representations, software architecture, impendance/admittance approaches, surface contact point approach, voxmap-pointshell method, friction in one contact point, haptic illusions.
motivation, 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,
construction of BVH's.
Sound rendering: motivation, human factors, mixing sound sources, image source method, beam tracing method
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.
- Ralf Dörner, Wolfgang Broll, Paul Grimm, Bernhard Jung (Hrsg.): Virtual und Augmented Reality (VR/AR), Grundlagen und Methoden der Virtuellen und Augmentierten Realität. Springer 2013. You can read the e-book from within the university's network.
- Kay M. Stanney (Ed.): Handbook of Virtual Environments. Lawrence Erlbaum Associates, 2002
- William R. Sherman, Alan B. Craig: Understanding Virtual Reality. Morgan Kaufmann.
- 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.
In order to acquire the "Schein", you will have to do a number of assignments. These will be mostly small practical programming assignments (based on a freely available VR system).
Online Literature and Resources on the Internet
- Tools that can "play" X3D- / VRML97 files:
- Introduction to VRML / X3D:
- A "Cheat Sheet" for VRML.
- SIGGRAPH 2008 Class Notes: Don't be a WIMP; These course notes not only discuss some post-WIMP interaction techniques, but also explain how to use some of the more advanced features of InstantReality, such as different stereo rendering modi, special interaction devices, clustering, scripting, animations, etc. (Source)
- The Annotated VRML97 Reference Manual (Source)
- The VRML Primer and Tutorial; those chapters that deal with HTML are not relevant for this course. In addition, the chapter on tools is outdated; but otherwise it is still a veritable introduction for VRML novices. (Source)
- The most important documents on the X3D standard:
- Examples for X3D / VRML:
- A large collection of materials,
both in VRML- as well as in XML encoding.
And here it is again as a ZIP archive.
- Links on socalled authoring tools; for VRML/X3D; if you want, you are welcome to use them. But if you have a decent programming editor (preferrably in ASCII), then you are probably more efficient with your editor.
- A handy little tool for Calculating VRML Viewpoints.
- Here are the -- not quite serious -- Cartoon Laws of Physics ;-) .
- More literature on the topic of user interface design:
- Literature on physically-based simulation in general:
- Norman Wittels: Introductory Vector Calculus (Source)
- 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)
- Literature on particle and on spring-mass systems:
- 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. (Source)
- The short novel
Gegen den Strich
by Joris-Karl Huysmans.
(Sorry, I have it in German only) Denkanregung: was hat das mit VR zu tun?
Last modified: Thu Feb 27 10:06:38 MET 2014