Boundary patch features

The boundary patch feature generates a planar or 3D surface from a closed 2D sketch, a closed boundary, or a mixture of both. The patches default to contact (G0), but can have edge conditions of tangent (G1) or smooth (G2) applied to each nonsketch edge in the Condition list.

You can also enable feature preview to view the results before creating the patch.

The boundary can be defined by the following methods:

Region selection You select one or more closed 2D sketches to form the single region. When a closed sketch is selected, the corresponding region is highlighted in the graphic window and you are limited to creating a planar patch. This technique is the same as profile selection for Extrude.

Sketch selection You select one or more closed 2D or 3D sketches to form a nonplanar patch. When a closed sketch is selected, the corresponding region is highlighted in the graphic window. Once the region is highlighted, you can use Select Other to select specific geometry within the sketch.

Edge Selection You select edges which define a closed loop. Because continuous edges must have the same edge condition, all selected surface edges that are tangent or continuous with the previous item are merged. Chaining stops at the first nontangent selection, even if they are stitched into a single surface.

Edge and Sketch selection A boundary can be defined by both edges and sketches. When you select a closed loop, the region is defined and highlighted in the graphics window. If preview is on, a preview also exists.

For all selection methods, the OK command is enabled once a closed loop is defined so that you can select additional loops. By selecting additional loops, you can define inner and outer loops that make islands in the surface. If a planar region is selected, selection of additional loops is not allowed.

Edge conditions can be applied to each nonsketch edge in the selection set for a loop. By default, all boundary segments are G0. You can apply G1 or G2 conditions to any nonsketch edges only if they have a single adjacent face. Boundary edges can include a mixture of G0, G1, and G2 conditions.

Procedures

Create a boundary patch feature

Use Boundary Patch to create a planar or 3D surface from a closed sketch, a closed boundary of edges, or a mixture of both. Apply conditions of contact (G0), tangent (G1) or continuous (G2) to each edge and preview the results before creating the patch. Once the first closed loop is selected, you can begin selections for a second loop.

Selections in an edge chain must be tangent continuous. To undo the last selection in an edge chain, right-click, and then select Undo Last Selection from the context menu. Repeat as needed to remove additional edges. To remove an item from the list, select it and press Delete.

NoteFor best results, stitch boundary patches to adjacent surfaces before creating features, such as sculpt, shell, and thicken/offset.

To create a boundary patch from a 2D sketch

Create a 2D sketch first. The sketch can include a single loop, multiple loops, intersecting loops, or islands. All loops selected in a single operation create one profile.

NoteYou cannot apply boundary conditions to sketches.

Click Boundary Patch. Select the profile to use for creating a boundary patch. Use Select Other to cycle through selectable geometry, and then click to select. Choose OK to create the boundary patch feature.

NoteYou can create a sketch with nested loops, and then choose the region outside the nested loop.

To create a boundary patch from a chain of edges

 

Click Boundary Patch. Select a chain of tangent, continuous edges which define a closed loop. Click the arrow under Condition to select a boundary condition for each edge or set of selected edges. Edges are G0 by default. NoteBecause continuous edges must have the same edge condition, all selected surface edges that are tangent or smooth with the previous edge are merged and listed as a single edge. Optionally, select another closed loop. Click OK to create the boundary patch feature.

NoteRegion selection is limited to planar patches. For nonplanar regions, select the first loop, use Select Other to cycle through selectable geometry, and then click to select.

Tip

• If you create a boundary patch with tangent constraints, avoid using supporting faces that are all perpendicular to one single imaginary plane. An angle that is not 90 degrees is expected.
• Avoid creating a boundary patch on construction geometry that consists of a single segment closed curve (circle, ellipse, or closed spline).

References

Boundary Patch

Creates a boundary patch feature by generating a planar or 3D surface within the specified boundary.

Access:

Ribbon:3D Model tabSurface panelPatch Ribbon:Repair tabModify panelBoundary Patch

Boundary

Specifies the boundary of the patch. Select a closed 2D sketch, a chain of tangent continuous edges, or a mixture of both to specify a closed region. Once the boundary selection represents a closed region, you can select the next boundary.

Condition

Lists the name for the selected edge and the number of edges in the selection set. It also specifies the edge condition to apply to each edge of the boundary patch. Click the arrow to select an edge condition. NoteBecause continuous edges must have the same edge condition, all selected surface edges that are tangent or continuous with the previous item are merged. Contact (G0) Tangent (G1) Smooth (G2)

NoteYou cannot apply tangent (G1) or smooth (G2) boundary conditions to selected sketches or edges that have two adjacent faces.

The selected edge in the following image is an example of geometry that does not support alternate boundary conditions.