Point

Key P. Places a node — a point that draws nothing but takes part in constraints.

Four points hold the centres of the circles: they never become material, but they say where it goes.
Four points hold the centres of the circles: they never become material, but they say where it goes.

What it is for

A point is an anchor. It never becomes material, but things refer to it:

  • the centre of a future hole: dimensions go to the point, and the hole is made from it (the Hole command can lay out holes straight from sketch points);
  • the centre of a circular array or an axis of symmetry;
  • where a vertex has to land in an assembly joint;
  • a node several dimensions hold on to at once — then one number is edited instead of five.

A point takes constraints too

It can be made coincident with another point, put on a line (point on line) or on a circle, or made the midpoint of a segment. Each of these removes degrees of freedom, so points are a convenient way to pin a sketch to geometry that already exists.

A point has degrees of freedom too

A free point adds two: it can move in X and Y. Until it is pinned by dimensions or constraints, everything resting on it moves with it. That is a common cause of “the part fell apart after an edit”: an undefined point beneath the feature.

Construction point

The X key turns a point into construction geometry: it stays visible in the sketch but takes no part in the outlines and never affects the body profile.

Polygon →