Introduction to Ygdrasil

Ygdrasil is a simple scripting language for creating interactive, immersive environments in virtual reality. It is used specifically for creating virtual worlds in the CAVE, and is designed to be easy enough to use that even beginning programmers can pick it up quickly. Ygdrasil is particularly useful for artists, who can use it to create interactive VR artworks without advanced training in computer programming, or support from specialized engineers. Ygdrasil is used in CAVE's worldwide, and can be used on a range of other kinds of VR systems or even just on a regular desktop PC. Ygdrasil gets its name from the Tree of Life in Norse mythology, and is often affectionately refered to as "Yg". Ygdrasil was written by Dave Pape at the Electronic Visualization Lab at University of Illinois, Chicago, and is currently maintained there by Alex Hill.

Virtual reality is a technology that, until recently, has not been generally accessible, particularly for artists. While VR has been used for decades in science, engineering, medicine, and military simulators, both the cost and technical complexity of the systems have limited the availability of the technology in the arts, education, or even in entertainment. In recent years, rapid increases in computing power and falling prices have brought the cost of an immersive display system down significantly, opening new opportunities for museums, art galleries, schools, and other areas in the arts and humanities. However, affordable technology still needs to be usable - and this is where Ygdrasil comes in.

Where to Get It

The main Ygdrasil home page is at http://www.evl.uic.edu/yg, where you will find the complete language reference, additional guides and tutorials, a user forum, and download and installation instructions for the most recent versions of the language. This guide is designed as a complement to the core documentation.

Ygdrasil is :

• a scripting language
• compact - for many things, you can do a lot without having to say a lot
• very extensible
• open-source (mostly)
• free (mostly)
• usable and desktops, laptops, ImmersaDesks, Head-mount displays, C-Walls and GeoWalls, all the way up to 4 and 6 wall CAVE's.

What you can do with it:

• Build fully-navigable 3D virtual environments
• Load 3D models and environments from a wide range of modeling packages - Maya, SoftImage, 3DStudio Max, Blender, Milkshape, Lightwave, Poser, Bryce, Nendo, MultiGen OpenFlight, and more.
• Script and animate interactive objects
• Add sounds, with spatialization effects
• Connect to sound applications and programming languages like Max/MSP, Pure Data, Reaktor, or SuperCollider to add generative sound synthesis and processing to your environment
• Display Quicktime movies as flat screens or texture-mapped onto objects
• Create networked, multiuser worlds
• Make a VR environment at home, then display it in the CAVE.

For example:

• architectural walkthroughs
• interactive stories
• games
• experimental art
• spatial and gestural interfaces
• electronic music