2000-02-25 - Part 1 Lecture 22: Virtual reality Immersive - - PowerPoint PPT Presentation

Mats Nyl´ en February 25, 2000 Slide 1 of 13

2000-02-25 - Part 1

• Lecture 22:

– Virtual reality – Immersive visualization environments – Interaction – Haptics – Systems – Steering

• Extra:

– CAVE article by Cruz-Neira, Sandin and DeFanti. – Virtual Windtunnel article by Bryson and Levit VIS00

Mats Nyl´ en February 25, 2000 Slide 2 of 13

Real, more Real, most Real

There is a progression towards Virtual Reality (VR). For example 1 2D Graphics 2 3D Graphics 3 Stereo Graphics 4 Viewpoint tracking 5 Immersion Where each step builds on the previous. VIS00

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Tracking

Getting an accurate tracking of viewpoints is fairly difficult, there are three basic approaches

• Mechanical
• Electromagnetic
• Camera based

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Immersive virtual environments

We can distinguish two main categories

• Those that project images individiually on each eye

– BOOM (now mostly obsolete) – HMD (Head mounted display)

• Screen projection based techniques

– CAVE (Fully immersive) – Virtual workbenches, immersadesks etc. (partial immersion) – Power walls (has enormous resolution) These type of systems can also include directional sound. VIS00

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The CA VE

Here is an illustration of a CAVE VIS00

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Interaction

Interaction in three dimensions opens up various possibilities and challanges. Examples are

• 3D-pointer, sometimes called a “wand”
• Palmtop menu systems (in CAVEs)
• Other 3D interactors, e.g., the “cubic” mouse
• Hand tracking

– Gestures – various types of gloves (e.g. pinch gloves) VIS00

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The cubic mouse

As an example of a 3D interacting device, let us consider the cubic mouse. It consists of a cube with three rods. The cubes positon and rotation is tracked, giving a total of 9 degrees of freedom. VIS00

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Haptics

Force feedback is also important. A common device is a phantom VIS00

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The Virtual Windtunnel

The Virtual Windtunnel, from 1992, represents an early example of a virtual environment for visualization VIS00

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Virtual Windtunnel

Here is an overview of the hardware configuration VIS00

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Computational Steering

The figure below illustrates computational steering (in this case “software in-the-loop”).

“Simulation” Transform Mapping Display Interactive Feedback Interactive Feedback Data

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Some references

A very incomplete list of web-sites

• EVL home page: http://www.evl.uic.edu/EVL/index.html
• Wonderland homepage:

http://www.hpc2n.umu.se/resources/wonderland/index.html

• VR-Cube page at PDC: http://www.pdc.kth.se/projects/vr-cube/
• Virtual Windtunnel Article:

http://www.nas.nasa.gov/ Pubs/TechReports/RNRreports/sbryson/RNR-92-013/RNR-92-013.html VIS00

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Summary and Outlook

This has been an overview of the use of virtual reality in scientific visual- ization. VIS00