Caching means that BS Contact stores downloaded content files on disk. The next time such a file is loaded - either because the user views the same scene again or because the file is part of multiple scenes - then this file can be loaded from disk, which is faster than retreiving it over the net again.
Special cases of a cache is Universal Media support and read only caches.
Cache Internet VRML worlds to the hard disk:
This enables/disables storing of files locally. However, turning this option off does not mean that disk space is freed. Just storage of new files is prevented.
Cache hard disk directory:
Specifies the directory to which BS Contact stores files for saving a network request when the file is needed again later. The amount of data that is stored here can be controlled in the Cache Settings tab.
The button labled "..." can be used to search for a suitable directory, and the button labled "View opens the cache directory in Explorer. The cache directory is organized in the same way as it is on the server. Therefore finding a file corresponding to an URL is easy.
The idea behind Universal Media is that a library of common media elements (textures, sounds and 3D objects) is stored locally on the client computer. Thus content that integrates these objects benefit by shorter loading time because these files don't need to be transferred over the network. BS Contact supports Universal Media by storing those elements locally the first time an application references them.
Incremental installation of Universal Media:
Specifies whether media objects that are part of the Universal Media library are stored on the local hard disk. However, turning this option off does not mean that disk space is freed. Just storage of new files is prevented.
Local Universal Media directory:
Specifies the directory where objects from the Universal Media library are stored. The amount of data that is stored here can be controlled in the Cache Settings tab.
The button labled "..." can be used to search for a suitable directory, and the button labled "View opens the universal media directory in Explorer.
The concept of a read only cache is similar to the one of Universal Media. The difference is, that with a read only cache BS Contact allows for applications that consist of high quality objects (detailed textures, long videos, etc) that is too large to be loaded over the Internet, but the application is though accessible as a web site.
Such an application would distribute the rich media objects on a CD or as a lengthy, but one time download that installs itself as a read only cache directory on the users hard drive. This application would have only the short main files and those that change over time on the web server. Thus the application can benefit from the advances of a web application, like access to the server data base and still can be as rich as a local application.
Additional read only cache directories:
Allows to enter a search path for a cache directory where BS contact reads files but never stores new files. This allows for applications that are distributed on CD ROM drives and contain a huge amount of pre-cached content on the CD ROM or in the Program Files folder on the hard disk.