Boundary PropertyManager

You can specify sketch curves, edges, faces, or other sketch entities to control the shape of a boundary feature.

When you select entities to define the boundary feature in two directions, you can select curves influence options that control how the selected entities influence the design.

To open the Boundary PropertyManager, do one of the following:

  • Click Boundary Boss/Base (Features toolbar) or Insert > Boss/Base > Boundary.
  • Click Boundary Cut (Features toolbar) or Insert > Cut > Boundary.
  • Click Boundary Surface (Surfaces toolbar) or Insert > Surface > Boundary Surface.

Direction 1

  Curves Determines the curves used to create the boundary feature in this direction. Select sketch curves, faces, or edges to connect. Boundary features are created based on the order of curve selection.
For each curve, select the point from which you want the path of the boundary feature to travel.
If the boundary feature connectors are incorrect, right-click in the graphics area and select Flip Connectors to try to fix them.
Incorrect connectors
Flip Connectors applied
Move Up and Move Down Adjusts the order of the curves. Select a Curve and adjust the order.
If the preview shows an undesirable boundary feature, reselect or reorder the sketches to connect different points on the curves.
  Dir1 curves influence Select one of the following:


Extends the curve influence to the entire boundary feature.

To Next Curve

Extends the curve influence to the next curve only.

To Next Sharp

Extends the curve influence to the next sharp only. A sharp is a hard corner of the profile. Any two contiguous sketch entities that do not have a common tangent or an equal curvature relation with respect to each other define a sharp. See Guide Curves in the Loft PropertyManager.

To Next Edge

Extends the curve influence to the next edge only.


Extends the influence of the curve uniformly over the entire boundary feature, similar to a ruled surface. This option helps to avoid excessive curvature (pocketing) effects by a highly-indented guide curve on surfaces where curves in a single direction are coincident to each other.

The curves influence option you select for a direction is applied to all selections in the direction. You can experiment by changing the curves influence options in one or both directions to control your boundary feature design.
Example: Curves Influence Options
The availability of curves influence options depends on the geometry of the curves you select for a direction.
  Tangent Type Select one of the following:


(Available when you have a minimum of three curves in the direction.) Approximates a parabola scribed between the first and last profiles. See Start/End Constraints in the Loft PropertyManager. The tangency from this parabola drives the lofted surface, which results in a more predictable and natural lofted surface when matching conditions are not specified.


No tangency constraint (zero curvature) is applied.

Normal to Profile

(Available when the curves are not attaching a boundary feature to existing geometry.) Applies a tangency constraint normal to the curve. Set the Draft angle and Tangent influence (%).

Direction Vector

Applies a tangency constraint based on a selected entity used as a direction vector. Select a Direction Vector , then set the Draft angle and Tangent influence (%).

Tangency to Face

(Available when attaching a boundary feature to existing geometry.) Makes the adjacent faces tangent at the selected curve. Set the Tangent influence (%).

Curvature to Face

(Available when attaching a boundary feature to existing geometry.) Applies a smooth, visually appealing curvature continuous surface at the selected curve. Set the Tangent influence (%).

  Alignment (Available only for single-directional cases.) Controls alignment of the iso parameters, which control the flow of the surface.
  Direction Vector (Available with Direction Vector selected for Tangent Type.) Applies a tangency constraint based on a selected entity used as a direction vector. The boundary feature is tangent to the selected linear edge or axis, or to the normal of a selected face or plane. You can also select a pair of vertices to set the direction vector.
  Draft Angle Applies a draft angle to the start or end curve. If necessary, click Reverse Direction . For single-direction boundary features, draft angle is available for all Tangent Types. For bidirectional boundary features, if you connect to an existing entity that has draft, Draft Angle is not available because the system automatically applies the same draft to the boundary feature at the intersecting curve.
  Tangent influence (%) (Only available with Global or To Next Sharp selected for curves influence and with curves in both directions. Not available with Tangent Type set to None or Default.) Extends the curve influence toward the next curve. Higher values extend the tangency's effective distance. This is useful for very rounded shapes. Example: Tangent Influence (%) Option
  Tangent Length (Not available with None selected for Tangent Type for any curve). Controls the amount of influence on the boundary feature. The effect of tangent length is limited up to the next section. If necessary, click Reverse Tangent Direction .
  Apply to all (Available only for single-directional cases.) Displays one handle that controls all the constraints for the entire profile. Clear this option to display multiple handles that permit individual segment control. Drag the handles to modify the tangent length. See Start/End Constraints in the Loft PropertyManager.

Direction 2

Same options as Direction 1 above. The two directions are interchangeable and give the same results regardless of whether you select the curves as Direction 1 or Direction 2.

Options and Preview

  Merge tangent faces Causes the surfaces in the resulting boundary feature to be tangent if the corresponding segments are tangent. See Options in the Loft PropertyManager.
  Close Surface Creates a closed body along the boundary feature direction. This connects the last sketch and the first sketch automatically.
  Trim by direction 1 and direction 2 Trims surfaces by direction when curves do not form a closed boundary. Example: Trim by Profile
  Drag Sketch Enables drag mode. When editing the boundary feature, you can drag 3D sketch segments, points, or planes from the 3D sketch from which contours have been defined for the boundary feature. The 3D sketch updates as you drag. You can also edit the 3D sketch to dimension the contours using dimensioning tools. The boundary feature preview updates when the drag ends or when you edit the 3D sketch dimensions. To exit drag mode, click Drag Sketch again or another selection in the PropertyManager. Video: Dragging a Sketch in a Loft
This ability is only available for a 3D sketch and only if the sketch was in the FeatureManager design tree directly before the insertion point of the Boundary Surface feature.
Undo sketch drag Undoes the previous sketch drag and returns the preview to its previous state. You can undo multiple drags and dimension edits.
  Show preview Displays shaded previews of the boundary feature. Clear this option to view the curves only.

Curvature Display

Mesh preview

Mesh density

Adjusts the number of lines of the mesh.

Zebra stripes  
Curvature combs Select at least one of these options:

Direction 1

Toggle the display of curvature combs along Direction 1.

Direction 2

Toggle the display of curvature combs along Direction 2.

Scale Adjusts the size of the curvature combs.
Density Adjusts the number of lines of the curvature combs display.