Researches on virtual prototyping presentation model based on directed acyclic graph

The key technique of virtual prototyping is real-time a performance simulation for a product, such as virtual assembly simulation and mechanism movement simulation. However, the key to realize this simulation is yet the representation of a product model, and but, the traditional digital model of a product (such as relation model and hierarchical model) doesn't meet the demand. Therefore, this paper provides a scene graph model of a digital product based on DAG. The definition of the scene graph model is given and the features to represent a virtual product with DAG are analyzed o Finally, the principles of dynamically assembling and disassembling product with DAG and its simulating method are explained with an example.