Constraints

Constraints are used to define the spatial relationship between entities or parameters of entities themselves. Some constraints such a distance or angle allow entering a value.

Some constraints can have a workplane. Unless otherwise noted, this means that the constraint applies in the workplane, that is all entities are projected onto the workplane.

In general, constraints are created by selecting the to be constrained entities and invoking the requisite tool.

Points coincident

Constrains two points to be at the same position.

Workplane:

optional

Selection:

Two points

Tool:

Constrain coincident

Point on line

Constrains a point to be on a line. Keep in mind that lines are infinite from the constraint’s point of view.

Workplane:

optional

Selection:

Line (2D or 3D), point

Tool:

Constrain coincident

Midpoint

Constrains a point to be at the midpoint of a line.

Workplane:

optional

Selection:

Line (2D or 3D), point

Tool:

Constrain midpoint

Point/line distance

Constrains the distance from a point to a line to be the entered value. The distance between a point and a line is the shortest path between the two, i.e. a line perpendicular to the line passing through the point.

Workplane:

optional

Selection:

Line (2D or 3D), point

Tool:

Constrain distance

Point on circle

Constrains a point to be on a circle or an arc. From the constraint’s point of view, arcs are full circles.

Workplane:

none

Selection:

Arc/Circle (2D or 3D), point

Tool:

Constrain coincident

Point in plane

Constrains a point to be in a plane defined by two lines.

Workplane:

none

Selection:

Two lines, point

Tool:

Constrain coincident

Point/plane distance

Constrains a point’s distance from a plane defined by two lines to be the entered value.

Workplane:

none

Selection:

Two lines, point

Tool:

Constrain distance

Distance

Constrains the (euclidean) distance between two points to the entered value. Selecting a line is equivalent to selecting its endpoints.

Workplane:

optional

Selection:

Two points or a line (2D or 3D)

Tool:

Constrain distance

Horizontal / Vertical distance

Constrains the horizontal/vertical distance between two points to the entered value. Selecting a line is equivalent to selecting its endpoints.

Workplane:

required

Selection:

Two points or a line (2D or 3D)

Tool:

Constrain horizontal distance, Constrain vertical distance

Horizontal / Vertical

Constrains two points to be at the same X position (vertical) or to be at the same Y position (horizontal). Selecting a line is equivalent to selecting its endpoints.

Workplane:

required

Selection:

Two points or a line (2D or 3D)

Tool:

Constrain horizontal, Constrain vertical

Diameter / Radius

Constrains the diameter or radius of a circle or an arc to the entered value.

Workplane:

none

Selection:

Arc or circle

Tool:

Constrain diameter, Constrain radius

Equal length

Constrains two or more lines to have the same length.

Workplane:

optional

Selection:

Two or more lines (2D or 3D)

Tool:

Constrain equal length

Equal radius

Constrains two or more arcs or circles to have the same radius.

Workplane:

optional

Selection:

Two or more arcs or circles

Tool:

Constrain equal radius

Workplane normal

Constrains workplane’s orientation to a plane defined by two lines.

Workplane:

none

Selection:

The to-be constrained workplane

Tool:

Constrain workplane normal

The tool is special in the way that it’s interactive. After invoking the tool, first click on the line that should define the workplane’s X axis, then on another line with a shared point to define the plane. Both lines must be in a group before the workplane.

Perpendicular

Constrains two lines to be perpendicular with respect to each other.

Workplane:

optional

Selection:

Two lines (2D or 3D)

Tool:

Constrain perpendicular

Line/points perpendicular

Constrains a line to be perpendicular to the vector between two points.

Workplane:

none

Selection:

Line (3D only) and two points

Tool:

Constrain perpendicular

Angle

Constrains the angle between two lines to the entered value.

Workplane:

optional

Selection:

Two lines (2D or 3d)

Tool:

Constrain angle

Arc/Arc tangent

Constrains two arcs to be tangent at a shared point.

Workplane:

none

Selection:

Two arcs

Tool:

Constrain parallel

Arc/Line tangent

Constrains a line and an arc to be tangent at a shared point.

Workplane:

none

Selection:

Line (2D only) and arc

Tool:

Constrain parallel

Parallel

This constraint can do two things:

  1. Constrains two lines to be parallel.

Workplane:

none

Selection:

Two lines (2D or 3D)

Tool:

Constrain parallel

  1. Constrains a line to be parallel to the normal vector of a workplane

Workplane:

none

Selection:

Line (3D only) and workplane

Tool:

Constrain parallel

Same orientation

Constrains two workplanes/STEP models to have the same orientation. There’s still one hidden degree of freedom along the normal in increments of 90°. Use the Rotate tool to get the entity to the target orientation.

Workplane:

none

Selection:

Two workplanes, two step models, or one workplane and one step model

Tool:

Constrain same orientation

Lock rotation

Locks the STEP model/workplane to the rotation set in the “Rotate” tool. Even with the constraint applied, the rotate tool can still be used.

Workplane:

none

Selection:

One workplane or STEP model

Tool:

Lock rotation