This is one in a series examining the purpose of X3D - where is it's niche in the electronic ecosystem and what function does it perform. The series also looks at where X3D needs to evolve to best serve the ecosystem. This post looks at animation. It was motivated by issues involving deformable skins that are needed to animate non-mechanical models.
X3D and VRML have been an international standard since 1997. They define a means to model and texture 3D geometry, animate it, and provide user interaction. As an International Standard (VRML: ISO/IEC 14772, and X3D: ISO/IEC 19775-19777) these have provided extraordinarly stable and long-lasting formats. Content developed 20 years ago still runs today. That is an important legacy that should not be lost. At the other end of the timescale (today), there are environments and capabilities that could not have been imagined when the first standard was approved. X3D needs to keep a foot in the ancient past (as far as computer time goes) and current so that history is not lost.
Imagine the situation where every house lock is made by one of three manufactures - Ambroid, Microlock, and Orange. All of the locks take your fingerprint to open, but each analyzes your fingerprint a little differently. Now the police need to enter your home (with justification). They do not have a fingerprint match, so they require Orange to create a keyhole for every lock that when using the proper key, the door will open.
November's terrorism attack in Paris elicited efforts by US officials to restrict or provide alternate means for decrypting messages. People in the Congress and the Intelligence Agencies repeated older requests for backdoors that would allow them to decrypt messages and content on devices.
The NY Times announced that they will be publisihing VR (360) news videos for Cardboard. They have just completed their second VR video. The Times will soon send all of their subscribers "Google Cardboard" to view these. There is another video scheduled for December and at least one more in 2016. This video, "The Displaced", tells the story of three children displaced by war and fighting and violence.
Events in X3D are the means for generating and handling behaviors. All changes in the state (including geometry, appearance, animation; but not animated images) are because at least one event was generated and processed. Events can be generated by timers, user interactions, response to other events, or from external sources. Events are routed fro a particular field of a node to another field of a different node. This cycle repeats throughout the time the scene is running.