DesignSpark Mechanical Online Help
Send Feedback

Use the Fill tool to fill in the selected region with the surrounding surface or solid. Fill can "heal" many cuts made into geometry, such as chamfers and rounds, subtractive revolves, protrusions, depressions, and regions removed by removing regions in the Combine tool. When using Fill to fill a gusset, the bend geometry on which the gusset is defined remains intact.

The Fill tool can also be used to simplify surface edges and cap surfaces to form solids. You can select a combination of faces and edges to replace them with a single new face.

You can use the Fill tool in Sketch mode to fill a loop of sketch curves that is almost closed, but that has multiple small gaps. If the gaps are too large, multiple error messages appear to show you where the gaps are. You can also use it to concatenate multiple sketched curves.

You can also use the Fill tool when editing a layout. Fill functionality is useful when you sketch faces across section lines, but do not want the section lines to split the surfaces when you switch to 3D.

When you change the geometry of a model, for example, the model’s length, height, or width, the model’s fill pattern will automatically update to correctly re-fill to the model’s new geometry.

Using the Fill tool

Click on one of the links below for detailed information about working with the Fill tool:

ShowSketch and layout curves

If you select one or more end points of sketch curves, the curves are concatenated into a single spline. Neighboring sketch curves are merged into one selectable item with an underlying spline. The spline is not displayed until the concatenated curve is modified:

Let's look at the following sketch curves:

One of the rectangles isn't closed. If we fill this rectangle, the loop is automatically closed and it becomes a surface:

The gap in this loop is small enough for the Fill tool to automatically close. Larger gaps will not be closed. If a gap is less than 1.5 times the length of the minor grid spacing on the sketch grid, the edges are extended to close the gap. If the gap is larger, a message appears in the status bar and the gap's endpoints flash.

The Fill tool also created surfaces from the other closed loops of sketch curves. The darker shaded areas in the image above show where the surface parts overlap. If we move the rectangle, we can see the surface that was created automatically:

The result only has edges for the sketch curves that we did not select, because the selected curves were used to create a separate surface.

Now let's go back and close the open rectangle, and let the Fill tool automatically create surfaces without selecting any edges:

This surface has edges for every closed sketch curve. The same thing automatically happens if we go from sketch mode to 3D mode.

If we select all the sketch curves, then click Fill, we get a surface without any interior edges:

You can also fill layout and sketch loops:

And a loop of non-tangent 3D curves:


You can select any number of edge points in any order. Each edge point is removed and a spline is created to make a smooth curvature change between the neighboring edges to the point:

If you Fill a vertex on a solid, the system attempts to merge coincident edges into a single edge:

ShowEdges on surfaces

If you select one surface edge in the shape of a spline or arc, the edge is simplified into a straight line:

If you select two or more edges of a surface, the edges are simplified with a straight edge between the end points:

If you select an edge that is completely within a surface, the edge is removed:

If you select all the edges that enclose a surface, the surface is simplified into a rectangle based on its extents:

If you select a single edge that lies on an analytic surface, Fill will simplify it with the neighboring edges:

You can fill irregular gaps on a circular surface, and the gap is simplified into a straight edge. Use Fill again on the straight edge, and the edge becomes round:

ShowChamfers on surfaces

Select a chamfer on a surface and then use the Fill tool to fill the chamfer.

ShowEdges on more than one face

If you select a chain of open, planar surface edges, Fill creates faces based on the edges you select:


If you select an open edge loop that belongs to multiple faces, Fill attempts to cap it with an analytic surface (cylinder, cone, etc.):

If you select a series of planar edges, you will get aplanar face:

If you select a series of surface edges that are not planar, Fill extends neighboring faces if the Patch Blend option is off:

If the Patch Blend option is turned on,

If you select an edge loop and Alt+click to select neighboring faces, the new face will be tangent to any faces you used Alt+click to select:

You can also extend neighboring faces to fill sliver gaps (double click to get loop):

If you select open edges of a self-intersecting surface, Fill tries to form a solid and remove excess (also works in combine):

If you select an edge loop and use the Patch blend and Tangent extension options:

When you fill a loop of edges, you can use Alt and select curves and the new face(s) will pass through the curves:

If you select an edge loop and guide curves, with or without the Tangent extension option (which applies to areas not influenced by guide curves):

If you select an imprinted edge on the face of a surface or solid, the imprinted edge is removed. This works the same as delete:

If you select laminar edge(s) of a solid or surface, Fill simplifies the edges by replacing them with a single edge with the same geometry:


If you select faces, Fill deletes them and extends neighboring faces:

If you select a chamfer or round, Fill removes them and adds them to a named group:

If you select rounds with neighboring rounds, Fill creates planar caps (because rounds should not be extended by definition):

If you select rounds on shelled parts, both faces of the shell are filled:

If you select joint edges created in Sheet Metal, the joints are removed:

If you select two imprinted edges, as shown below, they are combined into one edge:

ShowFaces and edges or sketch curves

With at least one face selected and at least one edge or sketch curve selected, Fill will remove the selected faces and create a single new face using the removed faces and the selected edges as inputs:

If you select two faces or surfaces that don't touch, you can replace them with a single face. You must double-click to select the gap between the faces:

ShowAny combination of sketch curves, layout curves, surface edges, and solid edges

When you select any combination of sketch curves, layout curves, surface edges, and solid edges that lie in the same plane and form a closed loop, Fill creates a planar surface:


You can also use the Delete key to fill faces on a solid or surface.

To fill a region

  1. Select the edges that define a surface region, or the faces that define a region within or on a solid.

    You can select an object in the Structure tree to simplify it.

    You can select faces and the Fill tool will automatically create a patch if you also select at least one edge.

  2. Click the Fill tool or press F.

To fill sketch or layout lines

  1. Select a closed or almost closed loop of sketch lines.

  2. Click the Fill tool or press F.

    If a gap is 1.5 times the length of the minor grid spacing on the sketch grid or less, the edges are extended to close the gap. If the gap is larger, a message appears in the status bar and the gap's endpoints flash.

    The mode is switched to 3D mode, and the filled loop becomes a surface.

    You can select the face of a solid when only the edge is displayed (such as in a drawing sheet view) using the scroll wheel. The edge becomes a slightly thicker line when the face is highlighted. If you fill lines in a layout, you can then pull the surface into 3D from the layout, but remain in edit layout mode after this action.

    You can fill lines and edges whether or not the sketched lines you want to fill were sketched in the same plane as the edges. (If the lines are imprinted on a face and become edges, filling those edges deletes them.)

Click the Fill tool in Sketch mode to fill any closed or almost closed loops and switch to 3D mode.

Tool guides

Within the Fill tool, there are several tool guides that let you specify the behavior of the Fill tool:

The Select tool guide is active by default. When this tool guide is active, you can select edges and faces to be filled. You can click an edge loop or use box-select to select multiple objects.

The Select Guide Curves tool guide allows you to select a guide curve.

The Complete tool guide generates the filled face.


The following options are available in the Options panel:


Simplifying edges

Simplifying edges across multiple faces

Filling with straight and curved edges

Filling with curved edges as guides

Capping a surface

Capping a surface that crosses multiple edges

Selecting internal edges to keep them after filling.

Selecting lines to simplify a surface by filling. Internal edges are removed.

Filling edges to form a solid

Patch blend with and without tangent extension. The Tangent extension option is select on the left, and not selected on the right.

©2013. All Rights Reserved.