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Parametric vs. Direct Modeling 

There are two approaches to creating CAD: parametric modeling and direct modeling. Both are useful for different aspects of the design process and can make your model creation much smoother. In this article, we’ll discuss the characteristics of both approaches, how they are made, and how the two compare to each other.  

Parametric Modeling

The parametric modeling method is a structured engineering process that is often referred to as history-based modeling. This is because it keeps a log of the model’s features, and as new features are added to the model, they are cataloged in this list, called a feature tree, making them easily accessible to edit. Each feature is made by manually inputting dimensions so that every measurement and angle is carefully controlled. The features are also controlled by parameters that have been defined by the engineer making the model. This enables the engineer to maintain design intent while creating and modifying the model because any modifications made will adhere to the set parameters that tell the model how to behave. 


  1. Structure – Every feature is controlled by dimensions, allowing for precise movements and modifications. 
  2. Design intent – The parameters keep the model from straying from the original design intent. These algorithms instruct the features how to react to changes made in other parts of the model. 
  3. Feature tree – The list that records each feature is easily accessible at all times and keeps a linear step-by-step creation log. 
  4. Automated changes – Whenever a feature’s dimensions are modified, the change is reflected in the visual model immediately. Identical features can also be edited simultaneously. 


  1. Concept design – When brainstorming options for a design, making many model iterations v