Knowledge Fusion classes are the basic building blocks of Knowledge Fusion programs. Classes are the blue prints of geometric objects such as blocks, splines, and sketches. Classes provide operations that you can perform on geometrical objects such as booleans, blends, and adding components to assemblies. Classes can also be non-geometric such as mass properties. There are also interface classes that allow Knowledge Fusion to carry out operations such as connecting to external databases, excel spread sheets, trigger optimizations, and so on.

Basic classes provided by Knowledge Fusion are called system classes. You can access these classes through the Add Child Rule dialog box. System class names begin with “ug_” or “nx_”. It should be noted that the classes starting with “ug_” are the traditional Knowledge Fusion System classes that were manually written. Classes starting with “nx_” are automatically generated through a common API.

While developing Knowledge Fusion applications, users write their own Knowledge Fusion classes that are a collection of System classes and/or other user-defined classes. These classes are called User classes and are written in the form of dfa files.

Classes have certain parameters that users can assign values to as arguments in order to instantiate the class. These parameters are called attributes of the class. For example, Length, Width, and Height are attributes of the system class ug_block. If these attributes are not passed any values in the form of arguments, default attributes of the class are used to create its instance.

Methods are a named set of instructions that carry out certain operations on the class they belong to. It is to be noted that unlike KF functions, methods always belong to a particular class. For example, addNewRecord is a method that belongs to the KF system class ug_odbc_Recordset and is used to add a new record to an instance of ug_odbc_Recordset.