Closing Gaps and Checking for Leaks

Identify and close any obvious gaps in the geometry. Run the leak detection tool to identify less obvious gaps and holes.

Two different tools are available to help close holes, namely the polygonal patch filler and the hole filler. The polygonal patch filler is a quick and easy way of closing arbitrary shaped holes which do not have a closed loop definition or are not planar. The process patches over the surface by creating faces that cover the hole area completely. The hole filler is a more exact method of filling well-defined holes by using a closed loop feature edge definition around the hole.

Open a scene. If you do not have a scene, create one.
Right-click Geometry > Operations > Surface Wrapper and select Run Leak Detection.
Leak detection cannot be launched if the current active scene is contained in a layout.
In the Graphics scene, click (Allow edges to be selected) at the bottom of the screen to allow edge selection in the scene.
Patch obvious holes or gaps:
1. If the hole is planar and has edges surrounding it, select the Repair Surface tab and use the (Fill holes using selected edges) tool. See The Surface Repair Tool: Filling Holes.
  You can double-click an edge to select all other connected edges.
2. If the hole is arbitrary, or is not planar, select the Repair Surface tab and use the (Fill Polygonal Patch) tool. See Repair Tools Reference: Fill Polygonal Patch Tool.
  To start creating a patch, click on a surface. To form a closed loop, continue clicking along the surface. To finish, right-click while placing the final point.
Check the geometry for leaks:
1. Click the Locate Points tab.
2. Set Current Point to Source Point.
3. Set the source point location, using one of the following options:
  - Define the point manually using the X, Y, and Z positions.
  - Define the point interactively using the point tool.
4. Set Current Point to Target Point and set the location as in the previous step.
5. If you require several target points, use one of the following methods:
  - Click New Target Point and set the location.
  - Click Target Point from VOI Seed Points.
    The Target Points from VOI Seed Points option converts all seed points created under Surface Wrapper > Volume of Interest > Seed Points to target points. The new target points are named using the VOI [Seed Point Name] convention and are stored in the Current Point menu.
  - Click Target Points from Gap Closure Points.
    The Target Points from Gap Closure Points option converts all seed points created under Surface Wrapper > Gap Closure > Seed Points to target points. If you have not activated Perform Gap Closure in the surface wrapper an error message is displayed in the Output window. The new target points are named using the GC [Seed Point Name] convention and are stored in the Current Point menu.
6. When you have defined all source and target points, click Recompute Template and Paths.
  If you run leak detection without activating the Legacy Wrapper, the operation generates the octree and performs the leak detection operation in parallel.
  
  If there are no leaks, the Output window reports the following:
```
No path found between source and target points.
These points will be on different sides of the final wrapped surface.
```
  If a leak is identified, a path from the source to the target point appears in the Graphics window.
  
  If multiple holes exist in the input surface, then a single target point only detects one of them. The addition of extra target points in different locations around the geometry or in different volumes helps detect holes that the wrapper did not fill. However, it is not guaranteed that adding a target point results in a new hole being found since the point location affects the computed path.
  
  Click New Target Point to include extra target points. Each leak path to a different target point is shown in a different color, even if it passes through the same hole. The Delete Current Target Point button can be used to remove a pre-existing target point from the calculation.
  
  Changing the location of any of source or target points, or adding or deleting target points requires the recalculation of the leak path. To recalculate the path, press the Recompute Paths button, which uses the previously defined template as the basis of the calculation.
7. Click Select Faces Close to Leak Path to highlight the faces that surround the hole.
8. Use the tools in the Repair Surface or Organize tab to fix any leaks that the tool detects.
Check for any remaining leaks:
1. Click Recompute Paths.
  Depending on the number of holes that are filled and their size, it can be necessary to recalculate the template by clicking Recompute Template + Paths. If there is any doubt whether leaks still exist, follow this approach as the safest route for leak detection. At any time during the surface repair operation, you can return to the Locate Points mode dialog and reconfigure the source and/or target points to assist leak detection to find holes. Once all leak holes are closed, you can proceed to wrap the surface and then use the surface remesher to improve the resultant quality.