About Constraints

The Drafting app lets you create geometrical constraints, which specify explicitly how the geometry should behave. A constraint applies to up to three elements.

In the Drafting app, constraints are created either through the constraints creation command or via Smartpick.

This page provides information that will help you understand and create constraints.

This page discusses:

See Also
In the Knowledge Base
Modifying definition of a geometrical element

What Is a Constraint?

A constraint is a kind of relationship that lets you specify explicitly how the geometry should behave. In other words, if you modify the geometry afterward via the geometry itself, these relations will be taken into account.

Geometrical constraints set a relationship that forces a limitation between one or more geometrical elements. The various geometrical constraints are the following:

  • Support lines and circles
  • Alignment
  • Parallelism
  • Perpendicularity
  • Tangency
  • Concentricity
  • Horizontality
  • Verticality
  • Fix
  • Middle point
  • Equidistant point
  • Symmetrical
Important: In the Drafting app, dimensional constraints do not exist as such. It is by Creating Driving Dimensions that you can drive constrained geometry.

How to Create Constraints?

You can create constraints by:

  • Selecting Show Constraints from the View section of the action bar.
  • Autodetection, that is by selecting Create Detected Constraints from the Sketch section of the action bar.

    This command creates detected constraints automatically.

You can also create constraints via SmartPick:

  • When you use SmartPick, you detect geometric constraints dynamically. But SmartPick can simply be used to detect constraints automatically without necessarily creating them. For information on creating constraints using SmartPick, see Creating Constraints via SmartPick.