Insert a point into a T-Spline body

Learn how to use the Insert Point tool to add edges within a T-Spline face in Fusion. Select points on an edge to position the new edge.

insert point example

The Insert Point tool can fine-tune a model by adding more edges to a T-Spline surface.

There are two modes for inserting control points:

Simple: Adding a point with simple insertion does not move the location of any other points. However, the surface shape is likely to change.
Exact: Exact insertion does not change the surface shape. It may add more control points and shift existing control points to keep the surface from changing.

Note: The Insert Point tool can have unexpected effects when used to create star points, triangles, and n-sided faces. Create these only when necessary. If the Insert Control Point tool creates no triangles or star points, the resulting surface should be fine.

The most common error with inserting control points is creating a model that you can view only in Box mode and can't convert to Smooth mode. You can correct this error with the Repair Body tool.

In the Design workspace, Form contextual environment, select Modify > Insert Point .
Select a point on the edge to edit, and continue to pick points.
To maintain the surface shape, in the Insertion Mode drop-down, select Exact.
Double-click when you finish.

Fusion recalculates the surface.

Tips

Inserting a point on a T-Spline edge provides more control over your shape, giving it an additional control vertex. Keep in mind that even though having more vertices means having more control, you will also have more geometry to manage.
Simple insertion mode only inserts the edges at the selected points but the shape of the body might change to maintain the number of edges.
Exact insertion mode maintains the shape of the body but adds edges to maintain that shape.
To minimize the impact on the existing body, insert points at the midpoint of edges (red snap points) then use Edit Form or other tools to move the edge. In exact mode, this minimized the number of faces created. In simple mode, this minimizes the change in the shape of the body.