Also, check the VRML Repository for information. Right then, events. As well as a number of fields, most nodes contain events . There are two types, eventIn and eventOut . Each event has a data type associated with it, as described above.
Some nodes have fields that are exposed .
These are an eventIn and eventOut for the field that can be used to set its value and notify the outside world when it has been changed. If a field is not exposed, it cannot be changed by events, and the value in the file is the one used at all times. To see which fields are exposed in each node, get hold of a reference guide from one of the places on the links page, or take a look at the node reference in the appendices to this tutorial. In order to do useful things with events, we need to somehow wire them together. Therefore, when the TouchSensor is clicked, the sound will play.