# GGCM Simple Constraint

A simple constraint refers to exactly two geometric entities. There are four types of simple constraints supported by the GGCM-ACIS Bridge, each with a function or a Scheme command to create them:

## Angle Constraint

• Satisfied if the minor angle between the two entities is equal to the client required angle.
• Can be applied to two lines, two planes or a plane and a line.
Angle Constraint of θ between a Line and a Plane

## Distance Constraint

• Satisfied if the distance between two entities is equal to the client required distance.
• Can be applied to pairs of points, lines or planes.
Distance between Two Planes (Also Requires an Angle of 0 or Π)

Note:

• plane/plane requires an angle constraint of 0 or Π
• plane/line requires an angle constraint of Π/2

## Incidence Constraint

• Satisfied if the distance from a point to a curve is zero.
• Can be applied to a point and a curve. (The point could be an end-point.)
Dragging an Edge with an Incidence Constraint at One End

## Tangent Constraint

• Satisfied if the angle between the line and curve is zero or Π and the distance from the line to the curve is zero.
• Can be applied to a line and a curve.
Tangency Constraint