Parametric Constraints — GstarCAD 2026
Parametric Constraints
Parametric constraint (geometric constraint) is a technique to associate and restrict two-dimensional geometric graphics and control objects to satisfy one or more geometric relationships. Geometric constraints are divided into twelve constraint types corresponding to twelve geometric relationships: COINCIDENT, COLLINEAR, CONCENTRIC, FIX, PARALLEL, PERPENDICULAR, HORIZONTAL, VERTICAL, TANGENT, SYMMETRIC, SMOOTH, and EQUAL.
This feature is only available in PLUS version.
Add the following parametric constraint-related commands:
Apply or make permanent geometric relationships between objects or points on objects.
Constrains two points to coincide or a point to lie on a curve (or the curve's extension).
Aligns two or more line segments to be in the same straight line direction.
Constrains two arcs, circles, or ellipses to share the same center point.
5、GCFIX
Locks a point or a curve in place, preventing it from moving.
Makes selected lines parallel to each other.
Positions selected lines at right angles to each other.
Aligns a line or a pair of points to be parallel to the X-axis of the current coordinate system.
Aligns a line or a pair of points to be parallel to the Y-axis of the current coordinate system.
10、GCTANGENT
Constrains two curves to be tangent to each other or their extensions to be tangent.
11、GCSYMMETRIC
Applies symmetry constraint to selected objects relative to a selected line.
12、GCSMOOTH
Constrains a spline curve to be continuous and maintain G2 continuity with other spline curves, lines, arcs, or polylines.
13、GCEQUAL
Adjusts the size of selected arcs and circles to have the same radius, or adjusts the size of selected lines to have the same length.
Displays or hides the geometric constraints on an object.
Removes all geometric and dimensional constraints from a selection set of objects.
Controls the display of geometric constraints on constraint bars.
Added parametric constraint related system variables:
Controls the display of the constraint bar for subsequent geometric constraints and controls the display of hidden constraints for selected objects.
Controls the display of geometric constraints on the constraint bar. Setting CONSTRAINTBARMODE to 4095 will display the constraint bar for all constraint types.
Controls whether geometric constraints are inferred during the drawing and editing of geometric figures.
Controls the text format of labeled constraints in the CAD software.
Controls the behavior of constraints when they are applied or edited.
Controls the transparency of the constraint bar. The valid range for the CBARTRANSPARENCY system variable is from 10 to 90. The higher the value, the more opaque the constraint bar is.