Introduction

Constraints specify geometric and dimensional properties of entities.

When working with Constraints, you can control the visibility of

• Constraint Icons
• Dynamic Dimensions

Additional tools let you

• Delete Constraints
• Manage Dimensional Constraints Parameters
• Modify Dimensional Constraints Parameters
• Set Constraint Options
• Set the Dimensional Constraint Dimension Text Format

Applying Geometric Constraints

Use the GeometricConstraint command to define Geometric Constraints for one or two entities.

To apply Geometric Constraints:

1. Type GeometricConstraint.
2. Specify an option:
   • Coincident: Defines a coincident geometric constraint to two points on entities or constrains a point on an entity to an entity.
   • Fix: Causes points on entities and entities to maintain fixed positions.
   • Perpendicular: Causes two Lines or linear PolyLine segments to be perpendicular to each other.
   • Parallel: Causes two Lines or linear PolyLine segments to be parallel to each other.
   • Horizontal: Causes Lines and linear PolyLine segments or pairs of points on entities to be parallel to the X-axis of the current coordinate system.
   • Vertical: Causes Lines and linear PolyLine segments or pairs of points on entities to be parallel to the Y-axis of the current coordinate system.
   • Tangent: Causes one entity to be tangent to another.
   • Smooth: Causes a Spline to constitute fluid geometric continuity with another Spline, Arc, Line, or PolyLine.
   • Collinear: Causes Lines and linear PolyLine segments to be collinear.
   • Concentric: Causes the center points of Arcs, Circles, Ellipses, or elliptical Arcs to coincide.
   • Symmetric: Causes two entities or constraint points on entities to lie symmetrically with respect to a symmetry line.
   • Equal: Constrains Lines to the same length, or Arcs and Circles to the same radius.
3. The options correspond to the choices provided by individual Geometric Constraints commands.
3. Follow the command prompts.
4. The subsequent sequences of the GeometricConstraint command are identical to those of the individual command variants. From the list of options above, click a link to see the command sequences.

Access

Command: GeometricConstraint

Understanding Geometric Constraints

Geometric Constraints define relationships that force dependencies and limitations between entities.

There are two types of Geometric Constraints: those that act on a single geometric entity and those that define a relationship between two geometric entities.  For example, the Fix, Horizontal, and Vertical Geometric Constraints act on a single entity, whereas Perpendicular, Parallel, Tangent, and others control two entities.

You can apply Geometric Constraints to 2D entities only.

Constraint Points

When you use a Geometric Constraint command and move the cursor over an entity, selectable constraint points are indicated with an icon .

This table lists the entity types to which you can apply Geometric Constraints. Also, it outlines valid constraint points per entity type:

This table lists the entity types that can have Geometric Constraints.

Entity Type	Constraint Points
Line	Endpoints, Midpoint
Linear PolyLine segment	Endpoints, Midpoint
Circle	Center
Arc	Endpoints, Midpoint
PolyLine Arc	Endpoints, Midpoint
Ellipse	Center
Elliptical Arc	Endpoints, Midpoint
Spline	Endpoints
SimpleNote	Insertion point, Alignment point
Note	Insertion point
Block	Insertion point
AttributeDefinition	Insertion point

 

Constraint Bars

Constraint bars group together the Geometric Constraints icons associated with an entity.

Example:

The constraints bar above shows that a horizontal, parallel constraint, collinear, and symmetric constraint are defined for a linear entity.

You can show or hide individual constraint bars, or show or hide them all. Also, you can relocate constraint bars to their default position. See: Controlling the Visibility of Geometric Constraint Icons.

Defining Coincident Geometric Constraints

Use the GcCoincident command to define a coincident geometric constraint to two points on entities or to constrain a point on an entity to an entity. It keeps two entities aligned with each other.

To define coincident points on entities:

1. Click Constraints > Geometric Constraints > Coincident (or type GcCoincident).
2. Specify the first constraint point on an entity (Line, linear PolyLine segment, Circle, Arc, PolyLine arc, Ellipse, or Spline).
3. Specify the second constraint point on another entity.
4. The entity you specified for the second constraint point is modified so that it is coincident to the entity you specified for the first constraint point.
5. A blue square marks the coincident constraint points. Move the pointer over the square to display the constraints bar for coincident points, then right-click the constraints bar to edit the constraint.

To define coincident points by specifying an entity, then a constraint point:

1. Click Constraints > Geometric Constraints > Coincident (or type GcCoincident).
2. Specify the Entity option.
3. Specify an entity (Line, linear PolyLine segment, Circle, Arc, PolyLine arc, Ellipse, or Spline).
4. Specify a constraint point on another entity.
5. The entity you specified for the constraint point is coincident to the constraint point of the first entity.

To define coincident points by specifying a constraint point, then an entity:

1. Click Constraints > Geometric Constraints > Coincident (or type GcCoincident).
2. Specify the first constraint point on an entity (Line, linear PolyLine segment, Circle, Arc, PolyLine arc, Ellipse, or Spline).
3. Specify the Entity option.
4. Specify an entity.
5. The entity you specified is coincident to the constraint point you specified initially.

Access

Command: GcCoincident

Menu: Constraints > Geometric Constraints > Coincident

Ribbon: Constraints > Geometric > Coincident

Defining Fixed Position Geometric Constraints

Use the GcFix command to cause points on entities and entities to maintain fixed positions.

To fix the position of constraint points:

1. Click Constraints > Geometric Constraints > Fix (or type GcFix).
2. Specify a constraint point on an entity (Line, linear PolyLine segment, Circle, Arc, PolyLine arc, Ellipse, elliptical Arc, Spline, Note, SimpleNote, or Block).
3. The constraint point is locked in place.

To fix the position of entities:

1. Click Constraints > Geometric Constraints > Fix (or type GcFix).
2. Specify the Entity option.
3. Specify an entity (Line, linear PolyLine segment, Circle, Arc, PolyLine arc, Ellipse, or elliptical Arc).
4. The entity is locked in place.

     If you fixed the position of a PolyLine segment, the segment is locked in place, but you can modify the geometry of the other segments.

Access

Command: GcFix

Menu: Constraints > Geometric Constraints > Fix

Ribbon: Constraints > Geometric > Fix

Defining Horizontal Geometric Constraints

Use the GcHorizontal command to make an entity or pairs of constraint points on entities parallel to the X-axis of the current coordinate system.

To define horizontal Geometric Constraints by specifying entities:

1. Click Constraints > Geometric Constraints > Horizontal (or type GcHorizontal).
2. Specify an entity (Line, linear PolyLine segment, SimpleNote, or Note).
3. The specified entity is aligned parallel to the X-axis of the current coordinate system.

To define horizontal Geometric Constraints by specifying two constraint points:

1. Click Constraints > Geometric Constraints > Horizontal (or type GcHorizontal).
2. Specify the 2Points option.
3. Specify the first constraint point on an entity.
4. This entity maintains its position.
4. Specify the second constraint point on the same entity or another entity.
5. The entity specified by two constraint points is aligned parallel to the X-axis of the current coordinate system.
6. If you specified the constraint points on two different entities, the entity specified by the second constraint point moves so that the second constraint point is aligned to the same X-axis as the first constraint point.

Access

Command: GcHorizontal

Menu: Constraints > Geometric Constraints > Horizontal

Ribbon: Constraints > Geometric > Horizontal

Defining Vertical Geometric Constraints

Use the GcVertical command to make an entity or pairs of constraint points on entities parallel to the Y-axis of the current coordinate system.

To define vertical Geometric Constraints by specifying entities:

1. Click Constraints > Geometric Constraints > Vertical (or type GcVertical).
2. Specify an entity (Line, linear PolyLine segment, SimpleNote, or Note).
3. The specified entity is aligned parallel to the Y-axis of the current coordinate system.

To define vertical Geometric Constraints by specifying two constraint points:

1. Click Constraints > Geometric Constraints > Vertical (or type GcVertical).
2. Specify the 2Points option.
3. Specify the first constraint point on an entity.
4. This entity maintains its position.
4. Specify the second constraint point on the same entity or another entity.
5. The entity specified by two constraint points is aligned parallel to the Y-axis of the current coordinate system.
6. If you specified the constraint points on two different entities, the entity specified by the second constraint point moves so that the second constraint point is aligned to the same Y-axis as the first constraint point.

Access

Command: GcVertical

Menu: Constraints > Geometric Constraints > Vertical

Ribbon: Constraints > Geometric > Vertical

Defining Parallel Geometric Constraints

Use the GcParallel command to make two elements parallel to each other.

To define parallel Geometric Constraints:

1. Click Constraints > Geometric Constraints > Parallel (or type GcParallel).
2. Specify the first entity (Line, PolyLine segment, SimpleNote, or Note).
3. The first entity is the one that maintains position, length, and orientation.
3. Specify the second entity (Line, PolyLine segment, SimpleNote, or Note).
4. The second entity is aligned parallel to the first entity.

Access

Command: GcParallel

Menu: Constraints > Geometric Constraints > Parallel

Ribbon: Constraints > Geometric > Parallel

Defining Perpendicular Geometric Constraints

Use the GcPerpendicular command to make two elements perpendicular to each other.

To define perpendicular Geometric Constraints:

1. Click Constraints > Geometric Constraints > Perpendicular (or type GcPerpendicular).
2. Specify the first entity (Line, PolyLine segment, SimpleNote, or Note).
3. The first entity is the one that maintains position, length, and orientation.
3. Specify the second entity (Line, PolyLine segment, SimpleNote, or Note).
4. The second entity is perpendicular to the first entity.

Access

Command: GcPerpendicular

Menu: Constraints > Geometric Constraints > Perpendicular

Ribbon: Constraints > Geometric > Perpendicular

Defining Tangent Geometric Constraints

Use the GcTangent command to make one entity tangent to another.

To define tangent Geometric Constraints:

1. Click Constraints > Geometric Constraints > Tangent (or type GcTangent).
2. Specify the first entity (Line, linear PolyLine segment, Circle, Arc, Ellipse, elliptical Arc, or PolyLine arc).
3. This entity maintains its position.
3. Specify the second entity (Circle, Arc, Ellipse, elliptical Arc, or PolyLine arc; or a Line or linear PolyLine segment, if the first entity was not a Line or linear PolyLine segment).
4. The second entity is aligned tangentially to the first entity. Entities can be tangent even if they do not touch.

Access

Command: GcTangent

Menu: Constraints > Geometric Constraints > Tangent

Ribbon: Constraints > Gemetric > Tangent

Defining Smooth Geometric Constraints

Use the GcSmooth command to cause a Spline to constitute fluid geometric continuity with another Spline, Arc, Line, or PolyLine.

To define smooth Geometric Constraints:

1. Click Constraints > Geometric Constraints > Smooth (or type GcSmooth).
2. Specify a Spline entity.
3. The constraint point displays at the start or end point of the Spline.
3. Specify a second entity (Line, PolyLine, Arc, or another Spline).
4. The primary Spline generates smooth continuity with the other entity.

Access

Command: GcSmooth

Menu: Constraints > Geometric Constraints > Smooth

Ribbon: Constraints > Geometric > Smooth

Defining Collinear Geometric Constraints

Use the GcCollinear command to make Lines and linear PolyLine segments collinear.

You can specify multiple linear PolyLine segments of one and the same PolyLine to make them collinear.

To define collinear Geometric Constraints:

1. Click Constraints > Geometric Constraints > Collinear (or type GcCollinear).
2. Specify the first entity (Line or linear PolyLine segment).
3. – or –
4. Specify Multiple, then specify the first entity.
3. Specify the second entity (Line or linear PolyLine segment).
4. If you use the Multiple option, specify other linear entities to make collinear to the first entity.
5. Press Enter.
6. The second and following entities are collinear to the first entity.

Access

Command: GcCollinear

Menu: Constraints > Geometric Constraints > Collinear

Ribbon: Constraints > Geometric > Collinear

Defining Concentric Geometric Constraints

Use the GcConcentric command to make the center points of Arcs, Circles, Ellipses, or elliptical Arcs to coincide.

To define concentric Geometric Constraints:

1. Click Constraints > Geometric Constraints > Concentric (or type GcConcentric).
2. Specify the first entity (Circle, Arc, Ellipse, elliptical Arc, or PolyLine arc).
3. The first entity is the one that maintains position.
3. Specify the second entity (Circle, Arc, Ellipse, elliptical Arc, or PolyLine arc).
4. The second entity moves so that its center point coincides with the center point of the first entity.

 When you specify a PolyLine arc as the second entity, only the specified arc segment is made concentric to the first entity; the geometry of the PolyLine changes instead of moving entirely.

Access

Command: GcConcentric

Menu: Constraints > Geometric Constraints > Concentric

Ribbon: Constraints > Geometric > Concentric

Defining Symmetric Geometric Constraints

Use the GcSymmetric command to make two entities or constraint points on entities to lie symmetric with respect to a symmetry line.

To define symmetric Geometric Constraints for two entities:

1. Click Constraints > Geometric Constraints > Symmetric (or type GcSymmetric).
2. Specify the first entity (Line, Circle, Arc, Ellipse, elliptical Arc, or linear or curved PolyLine segment).
3. Specify the second entity (an entity of the same type as the first entity).
4. Specify a symmetry line (Line entity).
5. The second entity is placed symmetrically to the first entity with respect to the symmetry line.

To define symmetric Geometric Constraints for two constraint points:

1. Click Constraints > Geometric Constraints > Symmetric (or type GcSymmetric).
2. Specify the 2Points option.
3. Specify the first constraint point on an entity.
4. Specify the second constraint point on an entity.
5. Specify a symmetry line (Line entity).
6. The second constraint point is placed symmetrically to the first constraint point with respect to the symmetry line.

Access

Command: GcSymmetric

Menu: Constraints > Geometric Constraints > Symmetric

Ribbon: Constraints > Geometric > Symmetric

Defining Equal Geometric Constraints

Use the GcEqual command to constrain Lines and linear PolyLine segments to the same length, or Circles, Arcs and PolyLine arcs to the same radius.

To define equal Geometric Constraints:

1. Click Constraints > Geometric Constraints > Equal (or type GcEqual).
2. Specify the first entity (Line, linear PolyLine segment, Circle, Arc, or PolyLine arc).
3. Specify the second entity (an entity of the same type, linear or curved, as the first entity).
4. The second entity is equal to first entity.

Access

Command: GcEqual

Menu: Constraints > Geometric Constraints > Equal

Ribbon: Constrains > Geometric > Equal

Controlling the Visibility of Geometric Constraint Icons

Use the ConstraintIcon command to show or hide Geometric Constraint icons and bars. You can also reset the constraint icons to their default position.

Constraint bars assemble icons of Geometric Constraints associated with an entity.

To control the visibility of individual Geometric Constraint icons:

1. Click Constraints > Constraint Icons > Specify Entities (or type ConstraintIcon).
2. Specify a Geometric Constraint entity.
3. If necessary, repeat step 2 for more entities.
4. Specify an option:
   • Show: Shows the constraint icons of the specified entities.
   • Hide: Hides the constraint icons of the specified entities.
   • Reset: Relocates the constraint icons of the specified entities to their default position.

To show all Geometric Constraint icons:

• Click Constraints > Constraint Icons > Show All (or type ConstraintIcon, then specify ShowAll).

To hide all Geometric Constraint icons:

• Click Constraints > Constraint Icons > Hide All (or type ConstraintIcon, then specify HideAll).

To reset all Geometric Constraint icons:

• Click Constraints > Constraint Icons > Reset All (or type ConstraintIcon, then specify ResetAll).

  Note: When you reopen a drawing that contains Geometric Constraints, all constraint icons are hidden. Use the ShowAll option of the ConstraintIcon command to redisplay them.

Access

Command: ConstraintIcon

Menu: Constraints > Constraint Icons

Ribbon: Constraints > Geometric > Constraint Icons Control

Applying Dimensional Constraints

Use the DimensionalConstraint command to define Dimensional Constraints for entities or between constraint points on entities.

Dimensional Constraints control the distance, length, diameter, radius, and angle values of entities. Changing the value of Dimensional Constraints changes the dimension of the related entities.

You can convert associative dimensions that you created using dimensioning commands to Dimensional Constraints (but not vice versa).

You can also use the DimensionalConstraint command to set the Dynamic or Annotation type for subsequent creation of Dimensional Constraints.

To apply Dimensional Constraints:

1. Type DimensionalConstraint at the command prompt.
2. Specify an option:
   • Aligned: Constrains the direct distance between two points on entities.
   • Horizontal: Constrains the horizontal distance between two points on entities.
   • Vertical: Constrains the vertical distance between two points on entities.
   • Linear: Constrains the horizontal or vertical distance between two defining points on entities.
   • Diameter: Constrains the diameter of a Circle, Arc, or curved PolyLine segment.
   • Radial: Constrains the radius of a Circle, Arc, or curved PolyLine segment.
   • Angular: Constrains the angle between three constraint points on entities or between two Lines or PolyLine segments, or to constrain the total angle of an Arc or curved PolyLine segment.
3. The options correspond to the choices provided by individual Dimensional Constraints commands.
4. Follow the command prompts.
5. The subsequent sequences of the DimensionalConstraint command are identical to those of the individual command variants.

To convert associative dimensions to Dimensional Constraints:

1. Type DimensionalConstraint.
2. Specify the Convert option.
3. In the graphics area, specify an associative dimension (linear, diameter, radial, or angular dimension).
4. A Dimensional Constraint replaces the associative dimension.
4. If necessary, edit the Dimensional Constraint value.

To set the type of Dimensional Constraints:

1. Type DimensionalConstraint.
2. Specify the Type option.
3. Specify an option:
   • Dynamic: Dimensional Constraints are not printed and use a predefined DimensionStyle.
   • Annotational: Dimensional Constraints are printed and use the current user-defined DimensionStyle.
4. Subsequent creation of Dimensional Constraints uses the specified type.
5. For detailed information about Dynamic and Annotation types, see Understanding Dimensional Constraint Types.
4. Specify another command option or press Esc to exit the command.

Note: Use the Properties palette to change the type of Dimensional Constraints.

Access

Command: DimensionalConstraint

Understanding Dimensional Constraint Types

You can apply two types of Dimensional Constraints:

There are two types of Dimensional Constraints:

• Dynamic: This type is shown only in the graphics area and do not print. It requires no user-defined DimensionStyle. The dimension text is positioned automatically. Dynamic Dimensions maintain the same size when zooming in or out.
• Annotation: This type is printed and uses the current DimensionStyle.

Also, you can decide whether Dimensional Constraints are

• Constrained: Geometry is driven from the dimension.
• Derived: Dimension is derived from the geometry.

Dynamic and Annotational Dimensional Constraints

Dynamic and Annotational Dimensional Constraints differ in the following characteristics:

Characteristics	Dynamic Constraints	Annotational Constraints
Zoom	Maintain the same size when zooming in and out	Change size when zooming in and out
DimensionStyle	Use a fixed, predefined DimensionStyle	Use the current user-defined DimensionStyle
Entity Properties	Ignore Layer, LineStyle, and LineColor settings	Use the current Layer, LineStyle, and LineColor settings
Print Output	Are not shown on printouts	Display on printouts

Defining Dimensional Constraints Parameters

You can control Dimensional Constraint geometry with mathematical equations and expressions.

Parametric equations include:

• The names of the Dimensional Constraints
• Expressions, in which you can use:
  • Values
  • User-defined variables, and variables that represent existing Dimensional Constraints
  • Mathematical operators, functions, and constants

Expressions for Dimensional Constraints

When you create a Dimensional Constraint, an equation defines the dimension of an entity or between points on entities in the form name=value, for example d1=12.34.

You can replace the value by an expression: name=expression.

• Within the expression, you can use values, variables, mathematical operators, and mathematical functions and constants.
• The result of an expression is a value.

A variable can be one of the following:

• User-defined, for example length1=12.5
• An existing Dimensional Constraint name, for example d2=rad1

Use the Parameters Manager to define and edit expressions and variables.

You can also edit expressions in-place.

Dimensional Constraints Equation Examples

Example	Description
d1=rad1	Sets the variable d1 to the value of the variable rad1.
d2=rad2*2	Multiplies the variable rad2 by 2 and sets the variable d2 as the result.
length1=cos(ang1)	Sets the user-defined variable length1 to the value of the cosine of angle ang1.
dist1=(length1 + d1) / 2	Sets the user-defined variable dist1 to the sum of the user-defined variable length1 and the variable d1 divided by 2.

 

Constraint Names

Dimensional Constraints (both Dynamic and Annotation constraints) are identified by name, as well as user-defined variables used in expressions and formulas.

The Parameters Manager lists all Dimensional Constraints variables with their names, expressions, and values.

The naming conventions are:

Meaning	Default Name	Constraints
Distance	d1, d2, …, dn	Aligned, Horizontal, Vertical
Diameter	dia1, dia2, …, dian	Diameter
Radius	rad1, rad2, …, radn	Radial
Angle	ang1, ang2, …, angn	Angular
User-defined	user1, user2, …, usern	Used in expressions

 

To rename constraint variable names:

1. Specify a Dimensional Constraint.
2. In the Properties palette, under Constraint, edit the Name.

– or –

1. Specify a Dimensional Constraint.
2. In the Parameter Manager palette, under Dimensional Constraints, edit the Name.

– or –

1. Double-click a Dimensional Constraint.
2. Edit the variable name in place.

Note: Constraint variable names must be unique.

Parametric Equations

Use operators and functions to define formulas and equations.

The evaluation of expressions follows standard mathematical rules.

Operators

You can use the following operators in expressions and formulas:

Operator	Description
+	Addition
–	Subtraction (or unary negation)
*	Multiplication
/	Division
^	Exponentiation
%	Floating point modulo
.	Decimal separator
(expr)	Parentheses to define expressions

 

Functions

You can use the following functions in expressions and formulas:

Function	Syntax
Cosine	cos (expr)
Sine	sin (expr)
Tangent	tan (expr)
Arc cosine	acos (expr)
Arc sine	asin (expr)
Arc tangent	atan (expr)
Hyperbolic cosine	cosh (expr)
Hyperbolic sine	sinh (expr)
Hyperbolic tangent	tanh (expr)
Arc hyperbolic cosine	acosh (expr)
Arc hyperbolic sine	asinh (expr)
Arc hyperbolic tangent	atanh (expr)
Square root	sqrt (expr)
Signum function (-1,0,1)	sign (expr)
Absolute value	abs (expr)
Truncate decimal	trunc (expr)
Round to nearest integer	round (expr)
Round down	floor (expr)
Round up	ceil (expr)
Largest element in array	max (expr1;expr2) *
Smallest element in array	min (expr1;expr2) *
Degrees to radians	d2r (expr)
Radians to degrees	r2d (expr)
Logarithm, base e	ln (expr)
Logarithm, base 10	log (expr)
Exponent, base e	exp (expr)
Exponent, base 10	exp10 (expr)
Power function	pow (expr1;expr2) *
Random decimal, 0-1	random
Constant pi	pi
Constant e	e

 

*) Uses the list separator (semicolon or comma) as defined in the OS format settings.

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Expression Evaluation

According to standard mathematical rules expressions are evaluated using the following precedence:

1. Expressions within parentheses (innermost parentheses first)
2. Standard operations order:
   1. Exponents
   2. Multiplication and division
   3. Addition and subtraction
3. Operators of equal precedence from left to right.

Defining Dimensional Constraints Quickly

Use the DcSmart command to quickly create Dimensional Constraints by specifying entities.

You can apply the command to Lines, linear and curved PolyLine segments, Arcs, Circles, and Rings:

• For linear entities parallel to an axis of the coordinate system, Aligned Constraints (parallel Constraints) are created.
• For linear entities not parallel to an axis of the coordinate system, either Aligned Constraints (constraining the absolute distance between two points) or Linear Constraints (constraining the horizontal or vertical distance between two points) are created – depending on where you move the pointer.
• For curved entities, Radial Constraints are created.

To define Dimensional Constraints quickly:

1. Type DcSmart at the command prompt.
2. In the graphics area, specif an entity.
3. Specify the location of the Constraints’ dimension line.
4. Repeat steps 2 and 3 as needed.
5. Press Enter.

Access

Command: DcSmart

Defining Aligned Dimensional Constraints

Use the DcAligned command to constrain the direct distance between two points on entities with respect to the current coordinate system.

To define aligned Dimensional Constraints by specifying two constraint points:

1. Click Constraints > Dimensional Constraints > Aligned (or type DcAligned).
2. Specify the first constraint point on an entity.
3. Specify the second constraint point on an entity.
4. The second point does not need to lie on the same entity specified with the first point.
5. The first and the second constraint points define the dimension line origin.
4. Specify the dimension line position.
5. The dimension line is created parallel to the axis defined by the two constraint points.
5. If necessary, edit the dimension parameter value.
6. Press Enter or click in the graphics area.

To define aligned Dimensional Constraints by specifying entities:

1. Click Constraints > Dimensional Constraints > Aligned (or type DcAligned).
2. Specify the Entity option.
3. Specify an entity (Line, linear PolyLine, or Arc).
4. Specify the dimension line position.
5. If necessary, edit the dimension parameter value.
6. Press Enter or click in the graphics area.

Access

Command: DcAligned

Menu: Constraints > Dimensional Constraints > Aligned

Ribbon: Constraints > Dimensional > Aligned

Defining Horizontal Dimensional Constraints

Use the DcHorizontal command to constrain the horizontal distance between two points on entities with respect to the current coordinate system.

To define horizontal Dimensional Constraints by specifying two constraint points:

1. Click Constraints > Dimensional Constraints > Horizontal (or type DcHorizontal).
2. Specify the first constraint point on an entity.
3. Specify the second constraint point on an entity.
4. The second point does not need to lie on the same entity specified with the first point.
4. Specify the dimension line position.
5. The dimension line is created parallel to the X-axis.
5. If necessary, edit the dimension parameter value.
6. Press Enter or click in the graphics area.

To define horizontal Dimensional Constraints by specifying entities:

1. Click Constraints > Dimensional Constraints > Horizontal (or type DcHorizontal).
2. Specify the Entity option.
3. Specify an entity (Line, linear PolyLine, Arc, or elliptical Arc).
4. Specify the dimension line position.
5. If necessary, edit the dimension parameter value.
6. Press Enter or click in the graphics area.

Access

Command: DcHorizontal

Menu: Constraints > Dimensional Constraints > Horizontal

Ribbon: Constraints > Dimensional > (Flyout) Horizontal

Defining Vertical Dimensional Constraints

Use the DcVertical command to constrain the vertical distance between two points on entities with respect to the current coordinate system.

To define vertical Dimensional Constraints by specifying two constraint points:

1. Click Constraints > Dimensional Constraints > Vertical (or type DcVertical).
2. Specify the first constraint point on an entity.
3. Specify the second constraint point on an entity.
4. The second point does not need to lie on the same entity specified with the first point.
4. Specify the dimension line position.
5. The dimension line is created parallel to the Y-axis.
5. If necessary, edit the dimension parameter value.
6. Press Enter or click in the graphics area.

To define vertical Dimensional Constraints by specifying entities:

1. Click Constraints > Dimensional Constraints > Vertical (or type DcVertical).
2. Specify the Entity option.
3. Specify an entity (Line, linear PolyLine, Arc, or elliptical Arc).
4. Specify the dimension line position.
5. If necessary, edit the dimension parameter value.
6. Press Enter or click in the graphics area.

Access

Command: DcVertical

Menu: Constraints > Dimensional Constraints > Vertical

Ribbon: Constraints > Dimensional > (Flyout) Vertical

Defining Linear Dimensional Constraints

Use the DcLinear command to constrain the horizontal or vertical distance between two points on entities with respect to the current coordinate system.

To define linear Dimensional Constraints by specifying two constraint points:

1. Click Constraints > Dimensional Constraints > Linear (or type DcLinear).
2. Specify the first constraint point on an entity.
3. Specify the second constraint point on an entity.
4. The second point does not need to lie on the same entity specified with the first point.
4. Specify the dimension line position.
5. Move the pointer along the X-axis to define a vertical Dimensional Constraint.
6. Move the pointer along the Y-axis to define a horizontal Dimensional Constraint.
5. If necessary, edit the dimension parameter value.
6. Press Enter or click in the graphics area.

To define linear dimensional constraints by specifying entities:

1. Click Constraints > Dimensional Constraints > Linear (or type DcLinear).
2. Specify the Entity option.
3. Specify an entity (Line, linear PolyLine, Arc, or elliptical Arc).
4. Specify the dimension line position.
5. Move the pointer along the X-axis to define a vertical Dimensional Constraint.
6. Move the pointer along the Y-axis to define a horizontal Dimensional Constraint.
5. If necessary, edit the dimension parameter value.
6. Press Enter or click in the graphics area.

Access

Command: DcLinear

Menu: Constraints > Dimensional Constraints > Linear

Ribbon: Constraints > Dimensional > (Flyout) Linear

Defining Diameter Dimensional Constraints

Use the DcDiameter command to constrain the diameter of a Circle, Arc, or curved PolyLine segment.

To define diameter Dimensional Constraints:

1. Click Constraints > Dimensional Constraints > Diameter (or type DcDiameter).
2. Specify a curved entity (Circle, Arc, or curved PolyLine segment).
3. Specify the dimension position.
4. If necessary, edit the dimension parameter value.
5. Press Enter or click in the graphics area.

  If you specify an entity for which a diameter or radius constraint is already defined, you receive a message that the constraint already exists.

Access

Command: DcDiameter

Menu: Constraints > Dimensional Constraints > Diameter

Ribbon: Constraints > Dimensional > Diameter

Defining Radial Dimensional Constraints

Use the DcRadial command to constrain the radius of a Circle, Arc, or curved PolyLine segment.

To define radial Dimensional Constraints:

1. Click Constraints > Dimensional Constraints > Radial (or type DcRadial).
2. Specify a curved entity (Circle, Arc, or curved PolyLine segment).
3. Specify the dimension position.
4. If necessary, edit the dimension parameter value.
5. Press Enter or click in the graphics area.

  If you specify an entity for which diameter or radius constraint is already defined, you receive a message that the constraint already exists.

Access

Command: DcRadial

Menu: Constraints > Dimensional Constraints > Radial

Ribbon: Constraints > Dimensional > Radial

Defining Angular Dimensional Constraints

Use the DcAngular command to constrain the angle between three constraint points on entities or between two Lines or PolyLine segments, or to constrain the total angle of an Arc or curved PolyLine segment.

To define angular Dimensional Constraints between three constraint points:

1. Click Constraints > Dimensional Constraints > Angular (or type DcAngular).
2. Press Enter to specify vertices.
3. Specify a constraint point on an entity for the vertex position.
4. Specify a constraint point on an entity for the angle start point.
5. Specify a constraint point on an entity for the angle end point.
6. Specify the dimension position.

   The position determines whether to measure the inner or outer angle.

7. If necessary, edit the dimension parameter value.
8. Press Enter or click in the graphics area.

To define angular Dimensional Constraints between two Lines or PolyLine segments:

1. Click Constraints > Dimensional Constraints > Angular (or type DcAngular).
2. Specify a linear entity (Line, or linear PolyLine segment).
3. Specify a second linear entity (Line, or linear PolyLine segment).

   When you move the pointer between the two lines, the preview shows the inner angle dimension. When you move the pointer outside the two lines, the preview shows the outer angle dimension.

4. Specify the dimension position.

   The position determines whether to measure the inner or outer angle.

5. If necessary, edit the dimension parameter value.
6. Press Enter or click in the graphics area.

To constrain the total angle of an Arc or curved PolyLine segment:

1. Click Constraints > Dimensional Constraints > Angular (or type DcAngular).
2. Specify a curved entity (Arc, or curved PolyLine segment).

   When you move the pointer, the angular dimension appears between the end points of the arc with the center point of the arc as the vertex.

3. Specify the dimension position.
4. If necessary, edit the dimension parameter value.
5. Press Enter or click in the graphics area.

Access

Command: DcAngular

Menu: Constraints > Dimensional Constraints > Angular

Ribbon: Constraints > Dimensional > Angular

Controlling the Visibility of Dimensional Constraints

Use the DcDisplay command to show or hide Dimensional Constraints.

To control the visibility of individual Dimensional Constraints:

1. Click Constraints > Dynamic Dimensions > Specify Entities (or type DcDisplay).
2. Specify a Dimensional Constraint.
3. If necessary, repeat step 2 for more entities.
4. Press Enter.
5. Specify Show or Hide to show or hide the specified dynamic dimensions.

To show all Dimensional Constraints:

• Click Constraints > Dynamic Dimensions > Show All (or type DcDisplay, then specify ShowAll).

To hide all Dimensional Constraints:

• Click Constraints > Dynamic Dimensions > Hide All (or type DcDisplay, then specify HideAll).

Access

Command: DcDisplay

Managing Parameters

Modifying Dimensional Constraint Parameters

Use the Parameters command to display the Parameters palette.

Use the Parameters command to display the Parameters Manager palette to view Dimensional Constraints parameters.

You can define, modify, rename, and delete constraint expressions and variables.

For detailed information about using expressions and variables, see Defining Dimensional Constraints Parameters.

You can do the following:

• Search a parameter by name
• Filter the list of parameters
• Sort the parameters list by name, expression, or value

The Parameters palette is available in the drawing and in the Block Editor.

• The Parameters palette (in the drawing) lists Dimensional Constraints parameters. See Managing Parameters from the Drawing.
• The Parameters palette (in the Block Editor) lists all parameters and custom properties from the block definition. See Managing Parameters from the Block Definition.

To display the Parameters palette:

• Click Constraints > Parameters Manager (or type Parameters).

To search a parameter by name:

• On the Parameters palette, type the name of the parameter in the search box in the upper-right corner of the palette and press Enter.

To filter the Parameters list:

1. On the Parameters palette, expand Filter.
2. Select an option to control the display of user-defined variables in the list:
   • All: Displays all user-defined variables.
   • Used in expressions: Displays only the user-defined variables used in expressions.
   • Unused in expressions: Displays only the user-defined variables not used in expressions. Right-click, then click Delete Parameter to remove unused variables from the list.

To sort the Parameters list:

• In the Parameters list, click a column name in the title bar (Name, Expression, or Value) to sort the list alphabetically according to the column title.
• Click the same column title again to restore the previous order.

Access

Command: Parameters

Menu: Constraints > Parameters Manager

Ribbon: Constraints > Manage > Parameters Manager

Hiding the Parameters Palette

Use the HideParameters command to hide the Parameters Manager palette.

To hide the Parameters Manager palette:

• Click Constraints > Parameters Manager (or type HideParameters).

Access

Command: HideParameters

Setting the Dimensional Constraints Type

Use the ConstraintType command to set the Dynamic or Annotation type for subsequent Dimensional Constraints.

To set the Dimensional Constraints type:

1. Type ConstraintType at the command prompt.
2. Specify an option:
   • Dynamic: Dimensional Constraints do not print and use a predefined DimensionStyle.
   • Annotational: Dimensional Constraints are printed and use the current user-defined DimensionStyle.
3. Subsequent creation of Dimensional Constraints use the specified type.
4. For detailed information about Dynamic and Annotation types, see Understanding Dimensional Constraint Types.

Note: Use the Properties palette to change the type for selected Dimensional Constraints.

Access

Command: ConstraintType

Converting Associative Dimensions to Dimensional Constraints

Use the ConvertConstraint command to convert associative dimensions to Dimensional Constraints.

To convert associative dimensions to Dimensional Constraints:

1. Type ConvertConstraint at the command prompt.
2. In the graphics area, specify an associative dimension (linear, diameter, radial, or angular dimension).
3. A Dimensional Constraint replaces the associative dimension.
3. If necessary, edit the Dimensional Constraint value.

Access

Command: ConvertConstraint

Menu: Constraints > Dimensional Constraints > Convert Dimensions

Ribbon: Constraints > Dimensional > Convert

Setting Dimensional Constraint Control Behavior

Use the DcDerived command to determine if the constraint or the geometry controls one another.

Normally the dimensional constraint controls the geometry, but this command lets you reverse it so that the geometry controls the value of the constraint, as with regular dimensions.

Derived constraints have brackets around the text. This command applies to selected entities.

To set dimensional constraint control behavior:

1. Type DcDerived at the command prompt.
2. Specify entities that are constrained by dimensions.
3. Specify an option:
   • Not derived. Dimensional constraint controls the size of the geometry (default).
   • Derived. Geometry controls the dimensional constraint and you cannot edit the constraint.
   • Inverse. Reverses the derived/underived setting of the selected entities.

Access

Command: DcDerived

Deleting Geometric and Dimensional Constraints

Use the DeleteConstraint command to remove Geometric and Dimensional Constraints from entities.

To delete Geometric and Dimensional Constraints:

1. Click Constraints > Delete Constraints (or type DeleteConstraint).
2. In the graphics area, specify entities with Constraints.
3. Press Enter.

  You can use the Parameter Manager palette to delete Dimensional Constraints.

Access

Command: DeleteConstraint

Menu: Constraints > Delete Constraints

Ribbon: Constraints > Manage > Delete

Setting Constraint Options

Use the ConstraintOptions command to set options for Geometric and Dimensional Constraints.

To define Geometric Constraint settings:

1. Click Constraints > Constraint Options (or type ConstraintOptions).
2. Expand Geometric.
3. Under Constraint icons settings, activate the Geometric Constraints to display in the graphics area.

   Click Clear all to cancel the selections or Select all to select all Geometric Constraints.

4. Specify whether to:
   • Show constraint icons only for entities in the current plane
   • Show constraint icons after applying constraints to specified entities
   • Show constraints icons when entities are specified
5. Under Constraint icons transparency, specify the transparency percentage for constraint icons in the graphics area.
6. Click OK.

To define Dimensional Constraint settings:

1. Click Constraints > Constraint Options (or type ConstraintOptions).
2. Expand Dimensional.
3. Under Dimensional constraint format:
   • In Dimension name format, select Name, Value, or Name and Expression.
   • Specify whether to Show lock icon for annotational constraints.
   • Note: The lock icon is not visible in print output.
4. Under Show options, specify whether to Show hidden dynamic constraints for selected entities.
5. Click OK.

Access

Command: ConstraintOptions

Menu: Constraints > Constraint Options

Ribbon: Constraints > Manage > Options

Setting the Dimensional Constraint Dimension Text Format

Use the SetConstraintNameFormat command to specify how to display the information in the dimensional constraints.

To set the dimensional constraint dimension text format:

1. Type SetConstraintNameFormat at the command prompt.
2. Specify an option:
   • Name. Displays only the name (for example, Length).
   • Value. Displays only the value (for example, 2.54).
   • Expression. Displays the name and the value, as an expression (for example Length = 2.54).

Access

Command: SetConstraintNameFormat

Related Topic

Working with Constraints