虚拟实体对象建模语言SCPL

VIRTUAL ARTIFACT MODELING LANGUAGE SCPL

本文给出一种新的虚拟实体对象建模语言ＳＣＰＬ．这种语言以基于控制论的行为模型ＳＣＰ为中心组织虚拟实体对象的建模，具有实现连续和更复杂行为的能力，适用领域较广．ＳＣＰＬ将行为的控制封装于对象内部，同时行为又可在虚拟实体对象类外部单独定义，可重用性好．ＳＣＰＬ还以自然的方式支持把具有行为的虚拟实体对象作为子对象．应用情况表明，该语言程序具有程序简洁明了，执行效率较高的优点，有效克服了已有建模语言在行为建模。

As a major approach to develop virtual reality applications, many virtual reality modeling languages have been proposed and implemented. However, these modeling languages still have some shortcomings, such as the lack of supporting behavior reuse or using artifacts with behaviors as sub artifacts, which restrict their wider application. For this reason, a new virtual artifact modeling language called SCPL, is proposed to solve these problems. Its principles, grammar, features, and some implementation details are given in this paper. SCPL is based on a Cybernetics based behavior model SCP. It is capable of describing complex behaviors such as continuous ones. In SCPL, the control of behavior is encapsulated inside artifact. The control mechanism such as events gathering, transmitting and reacting are all done by artifact itself. This feature makes artifacts' behaviors relatively independent and concurrent. Another noteworthy feature of this language is that behaviors can be defined outside of any artifacts, since the behaviors can be reused independent of artifacts. In addition, even nested sub artifacts with behaviors are supported naturally in SCPL. Finally, some comparisons between SCPL and some other virtual reality modeling languages are given. The results show that SCPL programs are more succinct and can run faster at run time.