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class In many cases it is desireable to combine objects into compound objects that behave as one object. This is possible by using the class statement. Example:
// define a class with a Cylinder and a Box
class AB		
	var a = Box(10,10,10); 
	var b = Cylinder({2,2,10}, {0,7,0}); 

// create an instance of class AB
var ab = AB();  
// rotate it. Box and cylinder will be rotated        
An object of class AB will be treated as one object, as demonstrated by the rotation.
method A class may have defined methods and also the construction of an instance can be parameterized. An example of a method is given below:
// define a class with a Cylinder and a Box
// z displacement should be given during construction
class AB(z)             
	var a = Box(10,10,z); 
	var b = Cylinder({2,2,z+10}, {0,7,0}); 
	function foo(x, y)
		a.move(x, 0, 0);
		b.move(0, y, 0);
		self.color = RGB(x,y,255);

// create an instance of class AB, z-displacement = 4
var ab = AB(4); 
// call method foo,20);  
The function foo is defined in the class scope of AB, and has two arguments x and y. Although an instance of class AB is treated as one object, an individual member of this object can still behave independently when it is modified directly. This is the case when the foo function is called.
self Also, the reference to the object itself is used to change the color by using the self keyword. The self keyword refers to the instance of a class, and can be used in a class definition only.