Using the Applet

 
This is a description of the applet and how the various components can be controlled to build the desired object.

• The various Applet Controls:
  • Canvas: This is where all the objects are drawn. The axes are also displayed on the canvas. All the objecs can be rotated by dragging the mouse on the screen.
  • Objects: These are the four basic solids that can be used. Double click on the desired solid to place it on the screen. All objects appear at the center of the canvas, which is the origin of the system.
  • Objects Placed: All the objects which are brought up are listed in this box and each object is assigned a distinct name to enable the user to select the intended object. A double-click on a solid selects that object and allows operations to be specified on it. The solids are named as:

    	Sphere		S#
    	Cube		C#
    	Cylinder	L#
    	Cone		N#
    

  • Scale, Rotate and Translate controls: These controls allow simple as well as composite objects to be scaled, rotated or translated. Values can either be entered directly or can be incremented/decremented using the "<" and ">" buttons. A solid in the Objects Placed list should have been selected before any of these operations can be applied to it. Whenever a solid is selected, it's scale, rotation and translation values show up in these boxes, to indicate where it currently is in the coordinate system.
  • Message Bar: This is used to display the various informatory messages to the user. The messages indicate when a new object has been created, when some solid has been selected, manipulted, if there was an error in user input and whether the Applet is currently engaged in computing the resultant object.
  • CSG operation string: The CSG string that specifies the CSG operation should be entered here. This string is an infix expression and should be of the form

    	{object1} {operation} {object2}
    	
    	The various operation should be specified as below:
    	Union             -    U
    	Intersection      -    I
    	Difference        -    M
    

    . The expression can contains parentheses which shoudl be used to group the operations.
    An example string is : C1 U (L1 I N2) where C1, L1 and N2 specify the first Cube, first Cylinder and second Cone placed, respectively. Another more elaborate example is: (C1 U L2) M (S1 I N1)
  • Delete button: This button can be used to delete any object that has been placed on the screen and then selected by a Double Click.
  • Reset button: The user can rotate all the objects on the screen by dragging the mouse in the direction in which he wants the objects to be rotated. The reset button can be used to bring the objects to the original unrotated position.
  • Clear button: This deletes all the current objects and provides the user with a cleared canvas.
  
  
  
• Some Examples.