Week4

Examples (all from Construct):

S3's Rio Project

Crutch

<embed src="faceBall.wrl" width="100%" height="50%">

Additional Nodes for Environments:

• Viewpoint
• Background
• NavigationInfo: speed, avatarSize, headlight, type, visibilityLimit
• Anchor

Manipulating the Viewer: elevator example
Gravity
Collision Proxies
Susan Kropf's navigation essay

Performance Optimization

• viewing frame rate in Cosmo: press "=" key to toggle display
• fewer polygons
• no primitives
• texture instead of polys
• colored polys vs textures, if slow target platform for texturing
• texture instead of text node
• use LODs (example from The Annotated VRML 2.0 Reference Manual )
• use Billboards rather than complex geometry (example from SGI's SIGGRAPH '97 VRML Course)
• use Anchors, rather than huge world
• use geometry hints: ccw, solid, and convex (use default TRUE if possible)
• create spatially grouped hierarchy so can remove chunks
• break objects into different parts so can be "taken out"
• use inlines with BBoxes (example from The Annotated VRML 2.0 Reference Manual )
• watch for "hot spots"
• arrange objects spacially in the vrml file
• use fewer nodes
• use min number of lights
• make vrml window smaller with embed: <embed src="noprotos.wrl" width=300 height=200>
• turn off collisions or use proxies (example from The Annotated VRML 2.0 Reference Manual )

Download Optimization

• use graduated download
• use text nodes
• use primitives
• reduce numerical precision, strip comments, whitespace, commas leading zeros...
• use quads instead of triangles
• compress files
• use inlines
• use generative scripts
• put initial position "indoors"
• use instancing
• use prototypes

mrl