A CAD approach where geometry is driven by editable parameters and constraints, so changing a value automatically updates the entire model.
In parametric modeling, every dimension, angle, and relationship in a design is stored as a named parameter or constraint in a feature history tree. Geometry regenerates automatically when parameters change. This contrasts with direct modeling (push-pull editing) where changes are immediate but not recorded. Tools like Fusion 360, SolidWorks, FreeCAD, and Onshape all use parametric history-based workflows.
Parametric modeling is ideal for parts that need variants: a single bracket model parameterized by bolt_hole_dia, wall_thickness, and length can generate an entire product family with one spreadsheet. For 3D printing, parametric models allow rapid iteration: change wall thickness from 2mm to 3mm and all dependent geometry updates in seconds without rebuilding from scratch.
Parametric models can become fragile when features reference geometry that later changes: a fillet referencing a deleted edge breaks the feature tree. This is called 'topological naming problem' and is a known weakness in many open-source CAD tools. Always name sketches and features meaningfully and avoid referencing geometry that may be suppressed in variants.
Related terms: Sketch Constraint, B-rep, Datum
| Field | 3D design, engineering |
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Engineer, author of The Big Book of 3D Printing and additive manufacturing expert