**5. Experimental results and discussion**

In the implementation of the Crazy ball 2 case study game, five game rules in terms of five modules are used namely: "Enemy Create", "Enemy Active", "Enemy Move", "Enemy effect", and "Enemy Attack". The "Enemy Create" module is basically used to create the desired enemy with some collection of predefined attributes and values. The "Enemy Move" module is used to move the enemy object based on its Move ID parameter. For instance, in the case of the "Bad Ball", enemy model, "Enemy Move" module will make it gain positive or negative speed based on the position of the player object. The "Enemy effect" module is used to make the object emit special effects or change colors based on its Effect ID parameter. The "Enemy Attack" module will make the enemy engages or do damage based on its Attack ID parameter. Finally, the "Enemy Active" module enables the enemy to receive collision and physics calculations. Figure 12 shows some screen shoots for the crazy ball 2 game environment with some enemies challenging modules.

State of the Art in Interactive Storytelling Technology: An Approach Based on Petri Nets 297

parallel in large virtual world. The proposed idea is supported by some case study called Crazy ball 2. Further research effort is still needed for establishing more relationship between the game workflow activity process and other entertainment game applications

*Ain Shams University, Faculty of Science, Mathematics & Computer Science Dept., Abbassia,* 

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with different graphics aspects, interfaces and contents.

Hussein Karam Hussein Abd El-Sattar

*Al-Yamamah University, CCIS, Riyadh, KSA* 

**Author details** 

*Cairo, Egypt* 

**7. References** 

press, 2006

2003

*2004.* 

Springer-verlag, 2007

**Figure 12.** Screenshots for Crazy ball 2 game environment with some enemies challenging modules.
