| As with all files destined for display on the World | | | | your PC hardware, which actually renders it in real |
| Wide Web, smaller is better with VRML (Virtual | | | | time. |
| Reality Markup Language). On a standard 28.8KB | | | | The term browser, as used here, refers to the |
| modem with average network traffic, a file of | | | | virtual reality viewer software that plugs into your |
| 150K downloads in about 120 seconds. To that, | | | | Web browser (Netscape or Internet Explorer or |
| you must add extra time for downloading any | | | | Firefox). Available browsers are reviewed later in |
| texture map files. Download performance, then, is | | | | the chapter. Keep in mind that performance that |
| the first issue: How long does it take to download | | | | depends on file size is a more subjective measure. |
| the file from the Web server and load it into | | | | What seems an unacceptably long download time |
| memory? | | | | to one person may seem quite acceptable to |
| This is a function of file size. The only time file | | | | another. |
| size might not be an issue is when you are | | | | Download time is the lesser of the two limitations. |
| creating virtualworlds for access over an intranet | | | | Generally speaking, you will not want to miss out |
| in a particular organization. The second issue is | | | | on the vitality that texture maps bring to your |
| navigation speed or performance after the file | | | | model for the sake of the extra time needed to |
| loads into memory, a function of model | | | | download them. What you definitely want to |
| complexity. This relates to file size, of course, | | | | avoid is creating models with so many faces that |
| because the more complex the model and the | | | | the computer gets bogged down trying to display |
| more faces it has, the larger the file. | | | | them. |
| The main bottleneck here, however, is in the | | | | There are many tools and techniques you can |
| video display: How many pixels does the video | | | | use to work with both these limitations to |
| display card have to process and put out to the | | | | produce VRML files optimized for download and |
| screen? When you navigate within a VRML world, | | | | navigation performance on the Web. |
| the browser interprets this code and passes it to | | | | |