Future Modifications :
1. Change on background color
It is more colorful if the applet allows user to change background color.
2. Grouping into single interface
It is more convenient if the applets can be put into one single interface.
3. Equations input by user
It is more useful if the applet allows user to input an equation, provided that the user has certain graphics knowledge.
4. Inputs of viewing system
It is more flexible if the direction of camera, light source and viewing point can be adjusted by user.