There are two "methods" of extending one or more faces.  

 

Method 1

 

Invoked By: Edit > Face

 

One method is invoked by this icon from the Free Form tool bar or from the Edit > Face pull down menu.  It extends multiple faces and edges of open shell features simultaneously. You can pick open edges from any face and VX attempts to maintain topological connectivity (i.e., closure).

 

The command prompts loop back so that you can select multiple edges of any face. A middle-click will end the command.  With this method you don’t have to explode the feature first.  First select an edge and then enter the amount to extend (or negative values to trim). You can optionally specify the extension type.  This method is only used to extend open edges of a face.

 

 

Method 2

Invoked By: (on a Face) > Extend

 

Another method of extending a single face can be invoked while in Object Edit mode.  First set the Pick Filter to "Face."  Then right-click on a face and select Extend from the pop-up menu.  With this method, only a single face is being operated on.  You can pick sewn edges to extend because the face will be exploded before any extension takes place.  This method also provides an additional option of sewing the extended face back into the shape from which it came.  Otherwise a separate shape is created.

 

 

Optional Inputs

 

Extension

Use this option to control the path of extended curves and surfaces.

 

• Linear - the extension follows a linear path. This is nice because it keeps extending away from the end in the direction of the tangent, but they do not match curvature. This causes among other things visual discontinuity.

• Circular - the extension follows a circular path in the direction of curvature. This is nice because it matches the existing curvature, but if you extend too far it will bend back around opposite to the tangent direction. If you want to extend out to some other curve or surface you may not ever get there.

• Curvature diminishing - allows you to keep the nice properties of both Linear and Circular. It matches curvature at the end and because the curvature reduces, it eventually becomes linear and heads away from the curve or surface end.

 

 

Sew extended face (Method 2 above only)

This option is only available during Object Editing when a single face is selected or highlighted.  Right-click and select Extend.  Then check this box to sew the extended face back into the shape from which it came.  Otherwise a separate shape is created.

 

 

 

Use this command to merge faces with common boundaries into one continuous face.  The faces do not have to belong to the same shape.  The edge boundaries of the two faces must coincide within the geometry tolerance defined by the Part Settings Form or the Set Feature Tolerance command whichever applies.  Faces can be merged incrementally using previously merged faces.

 

 

Optional Inputs

 

The sampling methods below only apply to cases where a complete refit (FEM surface fitting) is required. Planes, cylinders and untrimmed surfaces do not use these parameters and the default values will be acceptable.  The angle tolerance will influence all cases.

 

Normals

These are methods for setting the normal constraints along the boundary edges of the merged faces.  These are the edges that remain after the faces are merged.

 

• None - The surface normal direction along boundary edges are not fitted.

• Inner - The surface normals are evaluated from the original merged faces to which the boundary edges belonged to. This keeps the  original surface normal intact along those edges and is therefore the default option.

• Outer - The surface normals are evaluated at boundary edges from the "Outer" or neighboring faces that are not part of the merged faces. These are the surrounding faces that are joined with the final merged face along the boundary edges. This guarantees continuity of the merged face to its neighbor faces. Essentially, an n-blend is performed with the merged face and its neighboring faces with tangency turned on.

• Average - This is the average between the Inner and the Outer options above.  The final surface will have boundary edge tangency somewhere between the results of these two methods.

 

Sample

These are options for specifying what entities are sampled for points.

 

• Boundary - Sample only the outer Boundary Edges.  This is similar to the FEM Patch command.

• Edge - Sample all edges belonging to selected faces both inner and outer. There will be some interior points in addition to the boundary sample points.

• Face - Sample all edges and faces, for even more interior sample points.

 

Number

Specify the average number of points to be sampled for each edge of faces that are to be merged.

 

U-direction

This option allows you to specify the U direction of the merged face.  Select a direction.  You can right-click for additional directional input options.  This option is only relevant if trimmed faces are included in the merge.

 

Angle Tolerance

This is the angle tolerance (in degrees) for checking tangent continuity (G1) between two faces along their common edge. The faces to be merged requires G1 continuity.

 

FEM Settings / Spring Constant and Bending Resistance

Use the slider bars to set the spring constant and bending resistance values. For surface merging, the default values favor smooth flowing surfaces with 10-20 sample points per edge. See Finite Element Methods (FEM) for Surface Creation for more information.

 

Reset

This option resets the FEM Settings sliders to there system default positions.

 

 

 

Use this command to match the untrimmed edge of a face to a curve.

 

 

Required Inputs

 

Face

Select a face to modify. This form supports the selection of 4 face edges and matching curves (see below). They will correspond to the first 4 edges and matching curves you select. You can continue selecting more than 4 edges and matching curves if you wish but you cannot change your selections using this form.

 

1st - 4th edge

Select the first edge of the face to move. Then select the curve to match the edge to. Edges 2-4 are optional.

 

1st - 4th curve

Select the second edge of the face to move. Then select the curve to match the edge to. Curves 2-4 are optional.

 

 

 

Use this command to modify two adjacent faces so that they are tangent continuous along a shared edge. Master faces are those that will remain unmodified while slave faces are those that are forced to match them. Slave faces do not match each other. An exception to this is any master face that has a seam and meets no slave faces. The command will attempt to make its seam tangent.

 

 

Required Inputs

 

• Master - Select the master faces to match.

• Faces - Select the slave faces to reshape.

 

 

Optional Inputs

 

Influence

Use this option to specify the amount of global influence matching has on the slave faces. This factor is related to face "bending stiffness." The lower the number, the more localized the reshape will be.

 

• Enter the influence factor (1-9).

 

Notes

 

• Not all faces can be modified to be tangent with their masters due to insufficient degrees of freedom.

• Slave face edges that are incident on the master faces (not adjacent) are "unsewn" from their adjacent faces, if any.