What is Parametric Modeling

Parametric modeling is a modeling process with the ability to change the shape of model geometry as soon as the dimension value is modified. Parametric modeling is implemented through the design computer programming code such as a script to define the dimension and the shape of the model. The model can be visualized in 3D draughting programs to resemble the attributes of the real behavior of the original project. It is quite common that a parametric model uses feature-based, modeling tools to manipulate the attributes of the model.

Parametric modeling was first invented by Rhino, which is a 3D draughting software that evolved from AutoCAD. The key advantage of parametric modeling is, when setting up a 3D geometric model, the shape of model geometry can be changed as soon as the parameters such as the dimensions or curvatures are modified; therefore there is no need to redraw the model whenever it needs a change. This greatly saves time for engineers, especially in the scheme design stage. Before the advent of parametric modeling, the scheme design was not an easy task for designers, as the model is prone to be changed frequently. Therefore, changing the shape of a construction model was very difficult. Particularly, parametric modeling allows the designer to modify the entire shapes of the model, not just individual members. For example, to modify a roof structure, conventionally, the designer had to change the length, the breadth, and the height. However, with parametric modeling, the designers need to only alter one parameter; the other two parameters get adjusted automatically.