VRML

virtual reality modeling language

what is it?

• standardised (sort of) notation for virtual reality over the web

• text file (use normal text editor)

• bit like a programming language

• also special world building software

how do you use it?

• you need a VRML viewer– Netscape/IE plug-in– stand alone VRML viewer

• and a world– find one on the net– write your own!

interactivity over the web???

• 'world' is downloaded

• interaction is local– moving within the world

• links to the web?– can be linked to from web pages– active objects link back

versions

• VRML 1.0 first version 'static' worlds - only viewpoint changes

• VRML 2.0 animated objects in world tidying up etc.

N.B. VRML browsers highly inconsistent

VRML file format

• filename (URL) ends ".wrl”– c.f. .html, .gif, .jpg etc.

• VRML 1.0 first line: #vrml 1.0 ascii

• VRML 2.0 first line: #vrml 2.0 utf8

• can have binary versions too

contents of VRML file

• one or more nodes– general format

DEF object objecttype { fieldname value . . . }

– or simply: objecttype { fieldname value . . . }

types of nodes

• objects that appear in the world– e.g. sphere, cone, cube etc.

• nodes that alter subsequent objects– e.g. texture, color, transformations

• nodes that group other nodes– also limit the effect of transformations etc.

Examples

When you are looking at a virtual world in Netscape you can use:

View Menu - Page Source

and similar commands in other browsers.

sphere

#VRML V1.0 ascii

Sphere { radius 1}

add colour

#VRML V1.0 ascii

Separator { # groups things together Material { diffuseColor 1.0 0 0 # red green blue } Sphere { radius 1 }}

or texture map an image

#VRML V1.0 ascii

Separator { Texture2 { filename "big_alan.jpg" } Sphere { radius 1 }}

a cone

#VRML V1.0 ascii

Separator { Material { diffuseColor 0 0 1 # bright blue } Cone { height 3 }}

put them together ...#VRML V1.0 ascii

Separator { Separator { # for sphere Texture2 { filename "big_alan.jpg" } Sphere { radius 1 } } Separator { # for cone Material { diffuseColor 0 0 1 # bright blue } Cone { height 3 } }}

transform ...

… Sphere { radius 1 } ... Transform { translation 4 2 0 # 4 to the right and 2 up }…Cone { height 3 }…

putting bits together

simply several cuboidstexture mapped with wood grainand with a photo.

again and again

WWWAnchor { name "http://www.hiraeth.com/alan/" description "Alan's home page" WWWInline { name "alan.wrl” } }

• include other VRML files

• add hyperlinks