Repair Tools Reference

Surface Repair Tools

The Surface Repair tools repair errors on the geometry surface.

Delete selected faces

This tool deletes the selected faces from the part. The tool becomes available when you select at least one face.

The following example deletes unwanted faces from the solid part of a geometry.

Clicking Delete Faces removes the extraneous faces, leaving the fluid volume.

Create face from selected vertices

This tool creates a face using the selected vertices. The tool becomes available when you select three vertices.

The following example fixes free edges by creating a face. The three vertices are selected.

Clicking Create Faces from Vertices creates a face that is defined by the selected vertices.

Collapse selected vertices

This tool collapses one vertex to the location of another.

The tool also collapses an edge or face to its mid-point. If you select an attached vertex with an edge or a face, the tool collapses the edge or face to the selected vertex. The tool becomes available when you select two vertices, an edge or a face (with an optional attached vertex for edges and faces).

The following example collapses two vertices, which fixes a poor quality face. You can encounter this scenario when fixing cracks on the surface using the zipping tool.

Using the Collapse Vertices tool removes the poor quality faces, without creating free edges.

Split selected edges/faces

This tool splits a face or faces attached to an edge in half, using the mid-point of the selected edges. The tool becomes available when you select at least one edge or face. This tool is not available for quad faces.

The following example shows the splitting of two adjacent faces by splitting the connecting edge in half.

Using the Split Edges tool in this manner has the following results.

Swap selected edge

This tool swaps the connected edge between two faces. The tool is available when you have selected only one edge. This tool is not available for quad faces.

The following example swaps edges to improve face quality.

In this instance, the Swap Edges tool improves the quality of the connected faces, by reducing face skew.

Fill polygonal patch

With this tool you can define a patch around an arbitrary planar hole by clicking on the surface surrounding the hole. Each click defines a point on an edge of the patch.

Part Surface Options

The part surface options specify which part surface the polygonal patch face belongs to on creation. The following options are available:

• Default — uses the part surface associated with the first face clicked on.

• Specify — allows you to create a new part surface for an active part or use an existing part surface.

Note

If there is a face selected prior to opening the Create New Part Surface dialog, then the part that this face is associated with is automatically be pre-selected in the geometry part selector tool. The fill polygonal patch options are only available for part-based repair and part-based leak detection.

Define the patch using the cursor in the Graphics window to click points around the patch perimeter. End the patch definition by right-clicking a point, or by clicking the starting point.

The following example uses the Polygonal Patch tool to cover a hole before using the surface wrapper.

As the patch does not fill the hole exactly, the surface diagnostics report numerous errors. However, if you intend to use the surface wrapper, these errors are not an issue, as the surface wrapper only requires a closed surface.

To end the patch definition, right-click a point, or click the starting point. To abort the polygon patch definition and avoid creating a patch, press the Esc key.

Auto-repair surface errors

This tool automatically repairs errors reported by the following diagnostics:

• Face quality
• Face proximity
• Self-intersections

The tool uses two fixing mechanisms.

• Remesh — grows the problem area and surface remeshes, removing part curves if necessary.
• Patch — grows the problem area, deletes the local surface, and then invokes the hole filler.

First, the tool applies the remesher to faces identified as having a given error. If the remeshing succeeds in eliminating the issue or improving the quality, the tool takes no further action. If remeshing does not fix the error, the tool uses the patch option to remove the original error. You typically use the auto repair tool to resolve any errors that exist after surface wrapping.

Clicking Auto-repair surface errors starts the fixing process according to the above criteria. The tool only applies each fixing mechanism if you have run the diagnostic check for that particular type of error. For example, if you have not checked for face quality, the Auto-Repair tool does not fix any poor quality faces. If you have activated the Use distance based intersection option for pierced faces, the auto repair results may be different as the tool is dependent on the pierced faces, face quality and face proximity diagnostic results.

The Auto-Repair tool does not fix topological errors such as free edges, non-manifold edges, and non-manifold vertices. If these errors exist on the surface, you can fix them manually before using the auto repair process for the remaining issues. The auto-repair function is primarily designed for fixing single region or per-region cases that were surface wrapped. As such, the tool does not recognize interfaces between regions and can therefore potentially introduce errors on the faces if they are included in the active model.

Fill holes using selected edges

This tool fills a hole with new faces using the selected edge loops. See Filling Holes.

Zip selected edges

This tool locally zips faces together to remove free edges.

Select two or more edges before the tool becomes available. Right-clicking on the button provides access the same options as for zipping edges using part curves. If quad faces are involved in a zip operation, they are decomposed to triangles.

The following example uses the Zip tool to close a small crack on the surface mesh.

The tool projects the vertices on one side of the crack to the edge on the other side, and merges close vertices.

In some instances, the tool can produce poor quality faces, if it fails to merge close vertices due to tolerances.

You can fix these issues in several ways:

1. Select the short edge, and use the Collapse Vertices tool. This collapses vertices and removes the poor quality face from the surface mesh.
2. Select the close vertices and use the Merge Adjacent Vertices tool, with an adequate tolerance specified.
3. Select two or more free edges on the geometry, then:
   1. In the Selection Control group box, click (Grow selected) once or twice to grow the selection of neighboring faces.
   2. Click (Zip selected edges).

The selected faces are then locally surface remeshed. This eliminates the original faces and provides a high quality triangulation result. The advantage of this method over the other two is that it can be completely automated. There is no need to identify short edges or supply a merge tolerance.

Remesh selected faces

This tool locally remeshes the selected faces to improve the face quality.

The following example uses the local remesher to improve the quality of faces produced when filling holes.

Using the local remesher on the faces highlighted above has the following results.

The tool retains part curves or edges that are flagged as part curves on the surface. Select at least one face before this tool becomes available.

Remesh Face Options

The following options are available:

• Create Quad Faces — allows you to create a quad-based surface instead of a triangle-based surface. The face input selection can contain a combination of triangle and quad faces. The Specify Target Size and Do Curvature Refinement options can be activated to control the size of the quad faces.
• Modify Free Edges — when activated, this option allows the face remesher to adjust the edge tessellation on any free edges on a selected face. That is, the remesher is allowed to make the edge tessellation coarser or finer depending on the local edge sizes and the target surface size. To preserve the original edge tessellation on free edges during face remeshing, deactivate this option.

  Free edges that are part curves are treated as regular free edges during face remeshing.

• Specify target size — allows you to set the size of faces in the remeshed region. Deactivating the Specify target size option means that the surface remesher uses the local face edge lengths to determine the resulting size.

• Do Curvature Refinement — adds curvature-based refinement to the remeshing operation. You can specify the #Pts/Circle and Minimum Size values to improve surface definition on curved portions of the geometry.

  See Surface Mesher Controls and Values.

Smooth selected/attached vertices

This tool locally smooths a selected vertex, or vertices to improve the quality of the surrounding faces.

Use this tool if you want to refine the quality of a surface mesh by improving the distribution of vertices on a surface or along a part curve.

The Smooth Selected/Attached Vertices tool becomes available when you select at least one vertex, edge, or face.

Smooth Vertices Options

The following options are available:

• Unconstrained Smoothing — Use this mode to smooth vertices arbitrarily on a surface.
  • Preserve Feature Edges — ensures that the tool does not move vertices belonging to a part curve. However, where long chains of part curve vertices are selected, it is possible that these vertices are smoothed along the length of the part curve.
  • Reproject to initial surface — performs an additional step after smoothing, which attempts to project the selected vertices back to the original surface.
  The following example smooths the selected vertex to increase the quality of the attached faces.
  
  
  Using the Smooth Vertices tool with an appropriate number of iterations has the following result.
  
  
• Constrained Smoothing — Use this mode if you want to smooth vertices in a specified coordinate direction. This action moves vertices along the edge to distribute the vertices more evenly. The vertices are smoothed to increase the quality of the faces surrounding the selected edge.
  • Smooth in X/Y/Z direction — when activated, smooths vertices in the X/Y/Z direction.
  • Coordinate System — allows you to specify the coordinate system that you require. Set to Laboratory by default.

  Note	Smoothing must be allowed in at least one coordinate direction. Therefore, it is not possible to deactivate all three smoothing directions.

  The options to Reproject to the initial surface and Preserve feature edges are not available for constrained smoothing.

  The following example shows an edge that is selected for constrained smoothing in the Y-direction.
  
  
  The result after five iterations of smoothing shows that the vertices along the selected edge are smoothed in the Y-direction.
  
  

Merge adjacent vertices/duplicate faces

This tool merges adjacent vertices within a given tolerance and merges duplicate faces (that is, faces that share three vertices).

The tool is always available when you choose set Operate On to Active Model, or when you select a suitable face or vertex.

Merge Coincident Options

The merge options specify whether the tool merges adjacent vertices, duplicate faces, or both. The default options merge adjacent vertices and duplicate faces with a tolerance of 0.0001m.

• Merge Adjacent Vertices — when activated, the tool merges the vertices first. See Merging Vertices.
• Merge Duplicate Faces — when activated, the tool merges faces second. The tool deletes any collapsed faces or edges from the vertex merge operation in order to ensure a valid result. See Merging Duplicate Faces.
• Operate On — specifies whether the tool merges the currently selected faces and vertices, or all faces and vertices in the active model. The active model is the faces and vertices belonging to the parts originally selected in the Surface Repair Options dialog. The default option is to operate on the selected set only.

  When merging vertices using the selected set only, the tool removes all merged vertices from the current selection. Therefore, if you repeat the merge with an increased tolerance, the tool only uses unmerged vertices from the original selection. However, when merging duplicate faces, the tool retains all selected faces, apart from those faces that the merging process deleted.

  When merging using the active model, the tool deactivates any existing vertex or face selections. When vertex merging is complete, the tool selects the main vertex for each successful merge. Similarly, when merging faces, the tool selects the main face for each successful merge. You can use this information to judge the success of the merge, and where it took place on the part.

Repair Feature Tools

The Repair Feature tools repair errors on the feature edges on the geometry.

Flag edges as feature

This tool creates part curves for the selected edges, in order to maintain geometry details when creating the surface mesh.

The tool becomes available when you select at least one edge.

You can assign edges to a different part curve using the Part Surface / Part Curve Edit tool.

The tool adds marked part curves to the Surface Repair Edges part curve, which is located in the simulation tree under the Geometry > Part > geometry part > Curves manager.

You typically use this tool when a required feature is missing, after having used the Mark Features tool to create part curves automatically.

The following example flags the highlighted edge as a feature, in order to preserve the geometry detail during meshing.

Clicking Flag edges as feature creates a feature on the surface, which is marked with a thick black line.

Unflag feature edges

This tool deletes the selected part curves, in order to ignore geometry detail when surface remeshing.

The tool becomes available when you select at least one edge.

This example unflags all visible part curves in the image below, as they do not represent important geometry details.

Select the unwanted part curves using the mouse in the Graphics window.

Click the Unflag feature edges button to remove the selected part curves from the surface.

Mark features

This tool automatically creates part curves that are based on edge angle, free edges, non-manifold edges, patches, and boundaries.

The tool is always available, as no previous selections are required. The tool adds marked part curves to the Surface Repair Edges part curve, which is located in the simulation tree under the Geometry > Part > [geometry part] > Curves manager.

In some cases, automatically marking part curves creates some erroneous and unwanted part curves, which you can remove by using the Fix All and Unflag tools.

You can assign marked edges to a different part curve using the Toggle Select Curve Mode.

In the following example, features are marked by angle, with a sharp edge angle of 20 degrees. When complete, the Output window reports the number of part curves marked on the surface. In addition, the tool highlights all pre-existing and new part curves in the Graphics window.

Feature Edge Options

• Mark sharp edges — when activated, marks edges whose attached faces make an angle that is sharper than the value specified in Sharp Edge Angle as part curves. The default value is 31 degrees.
• Mark free edges — when activated, marks free edges as part curves.
• Mark non-manifold edges — when activated, marks non-manifold edges as part curves.
• Mark patch perimiters — when activated, marks underlying imported patch definitions as part curves.
• Mark boundary perimiters — when activated, marks part curves based on the perimeters of each of the currently selected boundaries.
• Operate On — specifies whether the tool marks edges for the current face selection set or for all faces in the active model. The active model is the faces and vertices belonging to the parts originally selected in the Surface Repair Options dialog. The default option is to operate on the active model.

Toggle Chase Edge Selection Mode

This tool selects edges manually using the shortest distance between two vertices.

This tool becomes available when you select the Edges filter. See Using the Chase Edge Selection Mode.

Toggle Select Curve Mode

This tool lets you quickly select the edges that have been marked as part curves by Mark Features by Angle, etc or related tools.

This tool becomes available when you select the Edges filter. See Using the Select Cuves Mode.

Fix all feature errors

This tool attempts to identify and repair common issues from other feature-marking algorithms. Common issues include changes in open feature edges, very short features, features that bound very small areas, and triangles where all three edges are marked as features (which can overconstrain the mesh). This algorithm, as opposed to other feature-marking algorithms which only focus on an edge and adjacent triangles, looks at chains of adjacent feature edges to make its decisions.

To make this tool available, run the feature diagnostics.

This tool only attempts to fix errors in explicit feature edges. Some errors in implicit feature edges are removed as a result of fixes to neighboring explicit feature edges, but the tool does not fix these directly. If implicit feature errors still exist after the tool has fixed the explicit feature errors, the cause is due to the underlying surface. In this instance, you can use the surface repair tools to fix surface errors, before repairing feature errors.

In this example, the cyan lines indicate explicit feature errors, as is typical when using feature diagnostics.

Clicking Fix all feature errors removes these explicit feature errors from the surface.

After fixing all errors automatically, inspect the surface and unflag any part curves that you do not want to preserve. For example, in the image above it would be advisable to unflag all the visible part curves, even though they are not errors.

Not a feature error

This tool defines a feature error as not erroneous, and removes the error from the diagnostics summary.

The tool becomes available when you select at least one edge.

It is possible the feature diagnostics marks a part curve as an error, but you consider the part curve to be valid. In this instance, select the part curve and click Not a Feature Error to define the feature error as valid. The feature error summary reduces, and the feature diagnostics considers the curves valid for the current session.

Flag vertices as feature

This tool creates part points for the selected vertices. Once flagged, the vertices are represented as bold, black squares in the scene. A part point entry, Surface Repair Points, is added to the simulation object tree under the Geometry > Parts > [PART] > Points node.

Note	This tool is only available when you enable part points in the simulation object tree.

Unflag feature vertices

This tool removes the selected part points.

This tool is only available when you enable part points in the simulation object tree.

Mark feature vertices

This tool marks feature points automatically based on either the active model or the current selection set, using options that you set.

To display the options for this tool, click to the right of this tool.

Note	This tool is only available when you enable part points in the simulation object tree.

Feature Vertex Options

The following options are available:

• Sharp Vertices Along Part Curves — when activated, marks vertices if the external angle between two connected part curves is greater than the value specified in Angle Between Edges
• Curve Free Ends — when activated, marks the open/free ends of any part curves.
• Curve Junctions — when activated, marks vertices where three or more part curves meet at a junction.
• Curve Type Perimieters — when activated, marks vertices where two or more curves of different curve types meet.
• Operate On — specifies what is used as the input. The Selected set only option uses any part curves attached to the current face and/or edge selection as the input. Note that at least one face or part curve (not just an edge) has to be selected in this case before the Mark feature vertices tool is enabled. The Active model option uses all part curves in the current model as the input.

On executing the operation, all relevant feature vertices are marked based on the supplied criteria. Any previously marked feature vertices that are re-marked by the process will have their point type changed to the new type (called Surface Repair Points). The newly marked feature vertices are selected so that you can change their type if necessary.

Repair Quad Tools

The Repair Quad tools allows you to create and modify quad surfaces.

Create face from selected vertices

With this tool you can create a single quad face by selecting four vertices. A quad face can be created from any four vertices, regardless of their location and what they are attached to.

Note	A duplicate quad face cannot be created (for example, one quad face on top of another quad face), since this is not allowed in the surface topology.

Create a quad face from two selected triangles

Allows you to create a single quad face from two existing triangle faces. The tool becomes available when you select at least two triangle faces. The triangle faces are replaced by a quad face.

Note	The triangle faces must share an edge in order for this tool to succeed.

Split selected quad faces into triangles

This tool splits one or more selected quad faces into triangles. Any selected triangle faces are ignored by this operation. On completion, the selection set contains the new triangle faces.