The Inner Fill function is used to fill interior holes and missing geometry on the outer boundary of  parts such as windows, wheel houses, tail light lamps, access holes, bolt holes, etc. as illustrated in Figure 7.1.68.

CREATE SURFACE

This option allows user to decide if surfaces are generated upon completion of the inner fill operation.

USE REFERENCE LINE

It is an advanced option. For filling complicated surface, the user can create some reference curves to fill the holes.

KEEP TANGENT

This option enables the user to maintain tangency between the existing surfaces and surfaces generated by the fill operation. Figure 7.1.69 illustrates the surface generated with and without tangency option.

Figure 7.1.69  Toggle on/off Keep Tangent option

ADVANCED

The advanced option includes some auxiliary functions that are mainly applied on single hole fill, as shown in Figure 7.1.70. These functions are used for generation of reference lines, removal of curves, surfaces and elements. Detailed description about these functions refers to Section 5.2.11 Surface Split.

Figure 7.1.70  Advanced option

DELETE

This option enables the user to remove the selected entities from the database.

MORPH HOLE SURFACE

This function enables the user to edit the filled hole by adding control lines. Clicking this button, the program pops up a dialog box illustrated in Figure 7.1.71. The user can toggle on the Tangent option to maintain tangency between the generated surface boundary after editing and the part. The user can click the Add, Edit or Remove button to add, edit or delete control lines, and click Preview to preview the generated surface after editing. The operations of this dialog box are similar to the one described in Section 7.2.3 Modify Binder.

Figure 7.1.71  Morph Hole Surface

There are four functions available in Inner Fill dialog box: Auto Fill, Hole Fill, Curve Fill and Polygon Fill.

TO PART

The user must specify a part prior to hole fill. The user may directly input a part name or click the select part button to select a created part.

·           AUTO FILL

After selecting this button and clicking Apply, the program will automatically find all the inner holes and highlight their boundaries, as shown in Figure 7.1.72.

Figure 7.1.72  Before Inner Fill

Simultaneously, eta/DYNAFORM prompts:

CLICK ON INNER BOUNDARY TO DE-SELECT

MIDDLE MOUSE BUTTON – DONE, RIGHT MOUSE BUTTON - CANCEL

If there are holes which do not need to be filled, the user can de-select them by mouse cursor and click on the middle mouse button to confirm. The result is shown in Figure 7.1.73.

Figure 7.1.73  After Inner Fill

REMOVE

Click this button to remove created Inner Fill.

EXIT

Exit the Inner Fill interface.

·           HOLE FILL

This function allows the user to fill holes individually. Once this function is selected, the boundaries of all the inner holes on the current screen are highlighted. The program prompts the user to select an inner boundary to be filled by using the left mouse button. After an inner boundary is selected, the program will automatically fill the hole, as illustrated in Figure 7.1.74.

Figure 7.1.74  Boundary Lines of Inner Holes

If Hole Fill function is selected, the Use Reference Line option is activated for the user to create some reference lines for hole filling, as illustrated in Figure 7.1.75.

Figure 7.1.75  Filled Mesh within a Closed Curve

·           CURVE FILL

This function allows the user to fill a cut-out area. Click Apply to highlight all the boundaries. The program will prompt:

SELECT A BOUNDARY TO FILL

Use the left mouse button to select a point on the boundary line to be filled. The program prompts:

SELECT A LINE TO CLOSE THE OPEN AREA

Select an existing line as the outer boundary to finish filling.

Figure 7.1.76  Before Curve Fill

Figure 7.1.77  After Curve Fill

Figure 7.1.76 and Figure 7.1.77 show the filling process in an open area using spline curve.

·           POLYGON FILL

This function allows the user to select a set of nodes as the boundary edge to create a mesh to fill the boundary. After the function is selected, the Select Nodes dialog box is displayed. The following message is printed in the message prompt window:

SELECT A SET OF NODES IN SEQUENCE ALONG THE BOUNDARY

After a set of nodes is selected, eta/DYNAFORM will generate a set of elements to fill the inner boundary.