A parametric object is an object that retains its parameters editable after going through different transformations (like resize, move, rotate), which means that you can always return to the initial shape. Parametric is a term used to describe a dimension’s ability to change the shape of model geometry as soon as the dimension value is modified.
Feature-based is a term used to describe the various components of a model. For example, a part can consist of various features such as holes, grooves, or chamfers. A feature is the basic unit of a parametric solid model. Designers will often use 3D parametric modeling when designing a group of products that include slight variations.
Parametric modeling uses the computer to design objects or systems that model component attributes with real-world behavior. Parametric models use feature-based, solid, and surface modeling design tools to manipulate the system attributes. One of the most important features of parametric modeling is that attributes that are interlinked automatically change their features. In other words, parametric modeling allows the designer to define entire classes of shapes, not just specific instances.
Before the use of parametric, editing the shape was a difficult task for designers. For example, to modify a 3D solid, the designer needed to change the length, the width, and the height individually. With parametric modeling, the designer only needs to change one parameter; the other two parameters are automatically adjusted. So, parametric models focus on the steps in creating a shape and parameterize them. This makes product design much faster and simpler.
Parametric models are built using a set of mathematical equations. For parametric models to work properly, they must be based on real project information. There are two popular parametric representation models:
In BR, a solid model is formed by defining the surfaces that form its spatial boundaries (points, edges, etc.) The object is then made by joining these spatial points. Many Finite Element Method (FEM) programs use this method, because it allows the interior meshing of the volume to be more easily controlled.
CSG defines a model in terms of combining basic (primitive) and generated (using extrusion and sweeping operation) solid shapes. It uses Boolean operations to construct a model. CSG is a combination of 3D solid primitives (for example a cylinder, cone, prism, rectangle or sphere) that are then manipulated using simple Boolean operations.
Here are a benefits that 3D parametric modeling offers over traditional 2D drawings: