Keyframe-Based Scenegraph Animation API for Virtual Reality Applications

Virtual reality (VR) applications are used in many areas of academic and industrial research areas including engineering, bio-medical & geo-sciences, among others. These applications generally focus on creating a VR environment to enhance user experience. One of the main challenges VR application developers face is to make objects within the environment move in a natural, realistic manner. Many commercial packages and programming libraries exist to help generate complex animations, including physics engines, game engines and modeling software such as Autodesk Maya. All of these tools are very useful, but have many disadvantages when applied to VR applications, as they were not designed for VR development. To address these issues, a VR application programming interface (API) was developed to help VR developers create and visualize natural, complex animations for VR-based systems utilizing OpenSceneGraph. This API, called the Animation Engine 2.0, was built in a manner animators and developers are already familiar with by integrating control points and keyframes for controlling animations. The system is time-based to scale to any size of VR system, which enabled the ability to support different time interpolations as well to incorporate acceleration into animations to create behavioral events such as a boing, bounce, or surge. In this paper, the Animation Engine API is presented along with its integration into a VR aircraft carrier application.