Tools menu: Fillet tool

What is the Fillet tool?

You can use the Fillet tool to round the edges of a 3D body, creating smooth transitions between adjacent faces. Fillets can soften sharp corners, improve the appearance of a model, and create rounded geometry for functional parts.

By default, a fillet has a circular cross-section with G1 (tangent) continuity to its neighboring faces. Where three or more filleted edges meet, the default corner type is Rolling Ball. You can adjust these settings to refine the resulting shape.

For an angled edge instead of a rounded one, visti Tools menu: Chamfer tool.

How to use the Fillet tool

Using the Fillet tool

To round one or more edges:

1. Go to Tools > Fillet. 
   For other ways to open tools, visit Accessing tools.
2. Select the edge or edges you want to fillet.
3. Drag the arrow to adjust the fillet, or enter a value in the dimension field. A radius fillet is created by default.
4. Optional: Select Fillet again from the menu to open the parameter card, where you can adjust the type, continuity, corner, and other settings. See Parameter Card and History Settings.
5. To finish and exit the tool, click anywhere in an empty area of the modeling space.

Chamfer and Fillet in direct modeling

When you select a body edge directly in the modeling space, you can create either a chamfer or a fillet by dragging the arrow in different directions:

• Chamfer: Drag the arrow toward the body to create a beveled edge.
• Fillet: Drag the arrow away from the body to create a rounded edge.

Once you start creating a chamfer or fillet, Shapr3D activates the corresponding tool. You can continue adjusting its parameters, but you can no longer switch between Chamfer and Fillet within the same operation.

Fillet types

Shapr3D supports two ways of specifying the size of a fillet:

• Radius – Defines a circular fillet using a radius. This is the default and is useful when a consistent circular transition is needed.
• Chord Width – Defines the fillet using the straight-line distance between the endpoints of its curved cross-section, rather than the radius. Use this when the width of the transition needs to be controlled directly.

Understanding fillet settings

You can refine a fillet's shape by adjusting its corner type, continuity, and cross-sectional profile. Use the Fillet parameter card to change these settings while the tool is active or from History.

Corner types

When multiple filleted edges meet, the Corner setting determines how their surfaces blend:

• Rolling Ball – Creates a corner with a constant radius. This is the default corner type.

  

• Setback – Sets back the edges where fillets begin blending into a corner, producing a blended face with a variable radius.

  

Continuity types

Continuity controls how smoothly a fillet meets adjacent faces:

• G1 (Tangent) – Maintains tangency between the fillet and adjacent faces. This is the default continuity type.

  

• G2 (Curvature) – Matches the curvature of adjacent faces for a smoother transition. G2 fillets have a non-circular cross-sectional profile.

  

Tip: The images use zebra stripes to help visualize curvature conditions. See Views and Appearance for more information.

Additional blending settings

The parameter card also includes Overflow, Curvature, Include Tangent Edges, and Y-Shaped Blend. These controls let you refine how the fillet behaves around neighboring edges and complex intersections. Refer to the parameter descriptions below.

Parameter Card and History Settings

Shapr3D records the tools you use as steps in History, allowing you to revisit and modify them later. Each History step stores its parameters, which you can access through the parameter card. You can adjust available parameters while using the tool or reopen them from History after completing the step.

Adjust Fillet parameters

While Fillet is active, select Fillet again from the menu to open its parameter card. The current card includes:

• Edge – Review or change the body edges selected for the fillet.
• Type – Choose Radius or Chord Width. Radius is selected by default.
• Radius / Width – Set the fillet size. The field is labeled Radius for Radius type and Width for Chord Width type.
• Continuity – Choose G1 – Tangent for tangency with adjacent faces or G2 – Curvature for curvature matching.
• Corner – Choose Rolling Ball (default) or Setback to control how fillets blend where multiple edges meet.
• Overflow – Control how the fillet handles overflow at nearby geometry. The original documentation lists Auto, Cliff, Smooth, and Notch; the screenshot confirms the setting and its default Auto, but not the full dropdown options.
• Curvature – Enter a value to adjust the fillet's curvature.
• Include Tangent Edges – Include tangent-connected edges in the fillet operation. This is enabled in the supplied screenshot.
• Y-Shaped Blend – Enable or disable Y-shaped blending at applicable intersections. This is disabled in the supplied screenshot.

To learn more about these controls, see Parameter Cards.

Edit Fillet in History

To modify an existing fillet:

1. Open the History sidebar.
2. Select the Fillet step you want to edit.
3. Review or modify the available settings.
4. To finish editing, click anywhere in an empty area of the modeling space.

These parameters are also available for review and adjustment when editing the Fillet step in History. The current parameter card labels the size selector Type (rather than the older Size Type label).

When to use the Fillet tool

Use Fillet when a model needs a rounded transition rather than a sharp or beveled edge.

• Soften exposed edges – Round corners on parts that will be handled or touched.
• Refine a product's appearance – Add smooth transitions to housings, enclosures, and other designed surfaces.
• Blend intersecting features – Adjust corner types and continuity to control how rounded faces meet.

Fillet vs. Chamfer

Fillet creates a rounded transition, while Chamfer creates a flat, angled bevel. Choose Fillet when you need curvature or smooth blending, and Chamfer when you need an angled edge.

Fillet	Chamfer

Best practices and troubleshooting

Best practices

• Start with the default radius fillet – Use a circular transition first, then adjust the continuity, corner, or other blending settings if needed.
• Check multi-edge corners – Compare Rolling Ball and Setback when several filleted edges meet.
• Choose continuity intentionally – Use G1 for tangent transitions and G2 when curvature matching is important.
• Use History for refinements – Revisit the Fillet step to adjust size, selection, or blending options.

Troubleshooting common issues