3D constraints create geometric relationships and 3D dimensions
between faces, edges, and vertices of shapes (including surface shapes) located in the same 3D shape representation or in different 3D parts. They control the position of the different elements in a shape as well as how elements move with respect to each other. Subsequent changes to shapes and 3D parts preserve the design intent by maintaining any 3D constraints added.
You can also add a 3D constraint
between a face, edge, or vertex of a natural shape and a feature of an external
app (for example,
Part Design
or
Generative Shape Design).
Note:
The reroute is available only if the constraint is satisfied with the new selected support.
The following geometric relationships and 3D dimensions are available:
Command Icon
Geometric Relationship
3D Dimension
Definition
Fix element in position
-
The Fix constraint locks a selected geometry to an absolute position.
Coincidence
-
The Coincidence constraint aligns selected geometries on the same plane.
Perpendicularity
-
The Perpendicularity constraint creates a 90-degree angle for two selected geometries.
Parallelism
-
The Parallelism constraint positions selected geometries in a parallel position.
Tangency
-
The Tangency constraint creates a tangency between two selected geometries.
Symmetry
-
The Symmetry constraint creates a set of equal dimensions between two selected geometries. The picker is used to select the reference geometry.
-
Distance
The Distance constraint lets you edit a distance value in the Selection Panel.
-
Angle
The Angle constraint lets you edit an angle value in the Selection Panel.
-
Radius dimension (cylinders)
The Radius constraint lets you edit a radius value between cylinders in the Selection Panel.
There are two types of 3D dimensions:
Driving dimension
Driving dimensions
are user-defined and constrain geometry to the value specified. They do not
update to reflect changes to content such as element
moves. This is the default 3D dimension type.
Driven dimension
Driven dimensions
are measured dimensions. They update to reflect changes to content, but cannot
be edited. Driven dimensions appear with brackets around the dimension value,
for example, (30).
Available Constraints by Entity
This table identifies the 3D constraints that can be created between the combinations of geometric entities listed below.
Vertex
Linear Edge
Cylindrical Edge
Planar Face
Cylindrical Face
Vertex
-
-
-
-
Linear Edge
-
-
-
Cylindrical Edge
-
-
Planar Face
-
Cylindrical Face
For cylinders and spheres, the table identifies the 3D constraints that can be created between the combinations of characteristic elements listed below.
Center
Axis
Face
Center
-
-
Axis
-
Face
Constraints can only be set in the folded view.
Note:
You cannot constrain 2D geometry.
Angle Constraints
Angle sector options in the Selection Panel give you control over how the angle is measured. Four angle sectors are available.
Angle sector 1:
Angle sector 2:
Angle sector 3:
Angle sector 4:
Note:
You cannot change the angle sector of angle constraints used in equations.
Orientation
Orientation options in the Selection Panel let you specify how elements move with respect to each other.
Orient the constraint
Orienting a constraint determines which side moves. An arrow shows the side that changes.
Notes:
If multiple constraints are added, constraints are solved as a system
and the best possible solution determined. In this case, you may not get the
expected result.
If one side is an external app feature, the constraint is always
oriented from the external feature to the natural shape.
No orientation
The system controls how elements move with respect to each other.
Constraint Status Conventions
3D constraints are displayed in different colors to facilitate identification and, if necessary, to repair.
Over-constrained
One or more constraints are over defining the shape. Dimensions or relations are in conflict or are redundant.
Appear in the color set in the Overconstrained constraint style option in Me > Preferences> General > Parameters and Measure > Constraints and Dimensions.
External App Features
When adding a 3D constraint, the external feature is copied locally as an External Reference (visible in the tree) and the 3D constraint references this external reference. The 3D constraint is oriented from the external reference to the natural shape and any changes affect the natural shape only.
Adding and rerouting a 3D constraint between an external app feature and a natural shape is unavailable if:
A mirror plane exists.
A constraint already exists between the natural shape you want to constrain and another natural shape.
The external feature is based on the natural shape you want to constrain.
Similarly, if a 3D constraint with an external feature exists:
The Mirror command is unavailable.
You cannot add or reroute constraints between the constrained natural shape and another natural shape.
You cannot base the external feature on a constrained natural shape.