Tools menu: Loft tool

What is the Loft tool?

You can use the Loft tool to create a shape that transitions between two or more cross-sectional profiles. Loft builds geometry between selected sketch profiles or faces, letting you control how the shape changes along its length.

Loft is useful for:

• Changing cross-sections – Transition between shapes of different sizes or outlines.
• Controlling complex forms – Use additional profiles and optional guide curves to influence the resulting shape.
• Creating smooth connections – Adjust continuity at the start and end of a loft when connecting it to existing geometry.

How to use the Loft tool

Before you start

Prepare the geometry that defines the loft:

• Loft profiles – Create at least two closed sketch profiles on separate planes, or identify existing faces to use as cross-sections.
• Guide curves (optional) – Prepare sketch curves or edges to control the shape of the loft between profiles. profile at its boundary. Guides help control the shape between profiles.
• Connection points – These are generated automatically when creating a loft without guide curves. You can adjust them to control how the profiles connect.

Note: Guide curves are optional. When guide curves are used, connection points are not available.

Using the Loft tool

1. Go to Tools > Loft. For other ways to open the tool, visit Accessing tools.
2. Select the sketch profiles or faces to connect. When using more than two profiles, select them in the order they should be connected.
3. Optional: Select the prepared guide curves or edges to influence the loft's shape. When not using guides, adjust the connection points if necessary to change how profile vertices correspond.
4. Optional: While the tool is active, select Loft again to open its parameter card. Adjust Periodic Loft, Start Continuity, End Continuity, or other available settings as needed.
5. To finish and exit the tool, select an empty area of the modeling space.

Understanding Loft elements

Loft profiles

Profiles define the cross-sections of the resulting shape. Loft requires at least two profiles and can use additional intermediate profiles to control the transition.

• Select profiles in the order they should connect.
• For solid lofts, use single closed cross-sections. Profiles on the same plane or intersecting cross-sections are not supported by the workflow described here.

Guide curves

Guide curves are optional sketch curves or model edges that control how the loft transitions between profiles.

• Each guide must intersect the boundary of every cross-sectional profile used in the loft.
• A guide that misses a profile boundary or passes only through its interior can cause the loft to fail.
• Use guide curves when profile shapes alone do not provide enough control over the transition.

Connection points

When a loft has no guide curves, you can use connection points to control how the profiles connect:

• Vertex mapping – Connection points automatically map vertices from one profile to another.
• Shape adjustment – Drag connection points to change how vertices correspond between profiles, introducing or reducing twists in the resulting shape.

Note: Connection points are not available when guide curves are specified.

Loft continuity settings

Continuity controls how smoothly the loft meets adjacent geometry at its starting and ending profiles. The parameter card provides independent settings for each end:

• None – No additional continuity constraint at that end.
• G1 – Tangent continuity, helping the loft meet neighboring geometry without a sharp change in direction.
• G2 – Curvature continuity, helping the transition maintain smoother curvature across the connection.

Use Start Magnitude and End Magnitude to adjust the influence of the corresponding continuity constraints on the loft's shape. These values do not represent a distance or wall thickness.

For a detailed explanation of G1 and G2, visit Understanding curve and surface continuity.

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 these parameters while using the tool or reopen the parameter card from History after completing the step.

Adjust Loft parameters

While Loft is active, select Loft again to open the parameter card. The available settings include:

• Profiles – Select or change the sketch profiles or faces that define the loft's cross-sections.
• Periodic Loft – Enable a periodic transition for lofts whose start and end profiles should connect in a continuous, closed cycle.
• Guides – Select sketch curves or edges to control the loft between profiles.
• Start Continuity – Choose None, G1, or G2 for the beginning of the loft.
• Start Magnitude – Adjust the influence of the start continuity setting.
• End Continuity – Choose None, G1, or G2 for the end of the loft.
• End Magnitude – Adjust the influence of the end continuity setting.
• Result – Choose the Boolean result: New Body, Union, Intersect, or Subtract, as appropriate for the surrounding geometry.

For more information about editing active tool settings, visit Parameter Cards.

Edit Loft in History

1. Open History.
2. Select the Loft step you want to edit.
3. Update the profiles, guides, continuity, magnitudes, or other available parameters.
4. Review the updated geometry in the modeling space.

When to use the Loft tool

Use Loft when a shape needs to transition between different cross-sections rather than extend a single profile in one direction.

• Changing profiles – Create a transition from a circular section to a rectangular or other closed section.
• Intermediate shape control – Add more profiles to influence the shape along its length.
• Guided transitions – Use guide curves to shape the surface between cross-sections.

Loft vs Sweep

Loft builds a shape between multiple cross-sectional profiles. Sweep carries a profile along a path. Both can produce curved geometry, but the choice depends on whether your design is primarily defined by its cross-sections or by a path.

Best practices and troubleshooting

Best practices

• Start with two simple profiles, then add intermediate profiles only where more control is needed.
• Select profiles in their intended connection order to reduce unexpected transitions.
• When using guides, make sure every guide meets every profile boundary.
• If a loft twists unexpectedly, check the connection points when no guide curves are selected.
• Use continuity controls when the loft needs to transition smoothly into existing geometry.

Troubleshooting