About Adaptive Geometry and Features

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Adaptive parts and geometry have underconstrained features and adjust to design changes. When you designate geometry as adaptive, you specify which elements are allowed to change and you control the elements that you want to remain a fixed size or position.

The following types of geometry can be made adaptive:

• Undimensioned sketch geometry
• Features created from undimensioned sketch geometry
• Features with undefined angles or extents
• Work features that reference geometry on other parts
• Sketches that contain projected origins
• Parts that contain adaptive sketches or features
• Subassemblies that contain parts with adaptive sketches or features

Note: Parts created in external CAD systems cannot be made adaptive because imported parts are considered fully dimensioned.

Uses for Adaptive Parts and Models

A part can be useful in multiple assemblies as long as it can resize as needed. When you create features in a part file, leave some sketch or feature geometry under constrained and define the features as adaptive. For example, drag an extrusion but leave its depth unspecified. After you insert a part with underconstrained features into an assembly, designate it as adaptive. When you constrain the part to fixed geometry, its adaptive features resize and change shape.

In an assembly, you can designate a subassembly as adaptive. When parts (and features) in the subassembly are designated as adaptive, features adapt when constrained to geometry outside the subassembly. You can drag under constrained components from within the context of its parent assembly.

You can use an existing part or subassembly to satisfy assembly requirements. Underconstrained features resize when you constrain them to a fixed assembly component. In an assembly file, start by selecting a part or subassembly whose features are set to be adaptive.

In general, use an adaptive model:

• When an assembly design that is not fully defined requires a part or subassembly in a particular position, but you do not know its final size.
• When the position or size of a feature depends upon the position or size of a feature on another part in the assembly.
• Only one occurrence of a part defines its adaptive features. If you use multiple placements of the same part in an assembly, only one occurrence can be adaptive. However, all occurrences reflect changes to it, including placements in other assemblies.
  Note: A component cannot be both adaptive and flexible at the same time. You can switch to flexible status to see the same subassembly with its components in multiple positions in an assembly.

Best Practices for Working With Adaptive Geometry

To ensure that adaptive features and parts update predictably:

• Use only one tangency per revolved feature.
• Avoid offsets when applying constraints between two points, two lines, or a point and a line.
• Avoid a mate constraint between two points, a point and a plane, a point and a line, and a line and a plane.
• Avoid tangency between a sphere and a plane, a sphere and a cone, and two spheres.

In assemblies with more than one occurrence of an adaptive part, constraints to non-adaptive occurrences sometimes require two updates to solve correctly.

In a non-adaptive assembly, you can constrain geometry to the origin work features (planes, axes, and origin point). In an adaptive assembly, the same constraints do not affect the position of components.

About Adaptive Work Features

Use adaptive work features to model relationships between geometric features and components in an assembly.

In the illustration, the work plane created in the tube part file is constrained to the face of another part. Even though the work plane "belongs" to the tube part file, it is not dependent on any tube geometry.

The tube end terminates on the work plane offset from the part face. The work plane in the tube part is adaptive because it allows the tube length to change if the associated face moves.

Both adaptive and nonadaptive work features can be:

• Created in a part.
• Used for construction operations such as termination planes or sketch planes for new features.

  An adaptive work feature is not constrained to geometry and can be positioned relative to other part geometry. A nonadaptive work feature maintains a constant relationship with the geometry used to create it, such as an offset distance.

  In an assembly, a work feature is adaptive because it is created in a part file, but is dependent on geometry from another part. For example, when a work plane is used as the termination plane for an extruded feature, the depth of the extrusion can change if the origin part moves. Because the work feature is constrained to the origin part, the extrusion extends or contracts when it moves.

  Adaptive work features are useful in assemblies for creating tubes, pipes, cables, and wires. Usually, you create a part file, and then create adaptive work features using existing parts for reference. Use the work features to create 3D lines for path sketches used in 3D sweeps.

  Use the endpoints of 3D lines and include geometry from 2D sketches, model edges, vertices, and adaptive work points to determine the shape of a 3D sweep path.

  Note: To create adaptive work features in an existing part you must have write permission for that file . If you create a part file to contain the adaptive work features, you can use existing components as reference, but do not need write permission for the reference files.