VRML virtual reality modeling language what is it

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 utf 8 • can have binary versions too

contents of VRML file • one or more nodes – general format DEF 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 V 1. 0 ascii Sphere { radius 1 }

add colour #VRML V 1. 0 ascii Separator { # groups things together Material { diffuse. Color 1. 0 0 0 # red green blue } Sphere { radius 1 } }

or texture map an image #VRML V 1. 0 ascii Separator { Texture 2 { filename } Sphere { radius 1 } } "big_alan. jpg"

a cone #VRML V 1. 0 ascii Separator { Material { diffuse. Color } Cone { height 3 } } 0 0 1 # bright blue

put them together. . . #VRML V 1. 0 ascii Separator { # for sphere Texture 2 { filename "big_alan. jpg" } Sphere { radius 1 } } Separator { # for cone Material { diffuse. Color 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 cuboids texture mapped with wood grain and with a photo.

again and again • include other VRML files • add hyperlinks WWWAnchor { name "http: //www. hiraeth. com/alan/" description "Alan's home page" WWWInline { name "alan. wrl” } }