4.4.1    General Overview

The Sketcher workbench itself features constraints - allowing 2D shapes to be constrained to precise geometrical definitions and a constraint solver, which calculates the constrained-extent of 2D geometry, and allows interactive exploration of sketch degrees-of-freedom.

Objects do not need to be drawn exactly as you intend to, because they will be defined later on by constraints. Objects can be drawn loosely, and as long as they are unconstrained, can be modified. They are in effect "floating" and can be moved, stretched, rotated, scaled, and so on. This gives great flexibility in the design process.

constrained sketch in edit mode (dimensions are visible only in the edit mode)

Instead of dimensions, Constraints are used to limit the degrees of freedom of an object.

sketch

Generally a 2D geometry is considered the starting-point for most CAD models - a simple 2D sketch can be 'extruded' into a 3D shape. Along with boolean operations, the sketcher forms the core of generative solid shape design.

solid shape after sketch extrusion

See also Sketcher Operations, Sketcher Geometries, Sketcher Constraints, Sketch Tools and Good Practises chapters for more information.