The **Spline ** tool creates a curve by marking specific points of curvature. This creates a polynomial curve, or curve with multiple points. With splines, you can construct curves and create organic shapes. Splines have two different types: **Fit Point** and **Control Point**.

## Fit Point Splines

To create a curve by marking the specific location of each point through which the curve should pass, use the **Fit Point Spline**. Fit Point Splines give you more flexibility to set the spline path. The challenge is controlling the whole curve since any change to a point impacts other parts of the spline.

To create Fit Point Splines, follow these steps:

- Define your sketch plane, go to
**Sketch**>**Spline**, then choose**Fit**.*For more advanced options for accessing this tool, visit: Accessing tools.* - Draw a line segment, then click to add points through which the curve should pass.
- Continue to add points to define the shape of the curve segments.
- To finish, press
**Escape**or**Backspace**. - To move the curve points, exit
**Spline**by pressing**Escape**, then click and drag the points. - To adjust the curvature at a point, click it and drag the handles.
- To add points to the spline, secondary click (right-click) on a curve to open the context menu, and select
**New Spline Point**. - To remove a point, select it and then click
**Delete**.

Constraints allow you to break or join splines at any point. To break or join splines at any point, select it and then click the **Break/Join** badge.

## Control Point Splines

Use **Control Point Splines** to draw and shape a curve indirectly. As you draw each section, a polyline appears to guide the curve. Each point that you mark is a vertex of an imaginary polyline that you can click/tap and move to adjust the shape of the curve. This approach gives you less direct manipulation, but more control over the full curve’s smoothness.

To create Control Point Splines, follow these steps:

- Define your sketch plane, go to
**Sketch**>**Spline**, then choose**Control**.*For more advanced options for accessing this tool, visit: Accessing tools.* - Draw connecting lines. This creates a polyline that guides the shape of the curve.
- To finish, press
**Escape**or**Backspace**. - To move the curve points, exit
**Spline**by pressing**Escape**, then click and drag the control points, not the curve itself. - To add a control point, secondary click (right-click) on a curve to open the context menu, and select
**New Spline Point**. - To remove a point, select it and click
**Delete**.

Constraints allow you to break or join splines at any point. To break or join splines at any point, select it and then click the **Break/Join** badge. To connect straight lines with a tangent curve, make sure the spline’s control polyline is in line with the neighboring lines. This will create the curve tangent at these points.

## Fit Point Splines

To create a curve by marking the specific location of each point through which the curve should pass, use the **Fit Point Spline**. Fit Point Splines give you more flexibility to set the spline path. The challenge is controlling the whole curve since any change to a point impacts other parts of the spline.

To create Fit Point Splines, follow these steps:

- Define your sketch plane, go to
**Sketch**>**Spline**, then choose**Fit**.*For more advanced options for accessing this tool, visit: Accessing tools.* - Draw a curve segment, then lift the pen.
- Draw more connecting curve segments.
- To move the curve points, select and drag them directly.
- To adjust the curvature at a point, drag the handles.
- To add points to the spline, select the curve and long-tap it.
**To remove a point, select it and then tap****Delete**.

Constraints allow you to break or join splines at any point. To break or join splines at any point, select it and then tap the **Break/Join** badge.

## Control Point Splines

Use **Control Point Splines** to draw and shape a curve indirectly. As you draw each section, a polyline appears to guide the curve. Each point that you mark is a vertex of an imaginary polyline that you can click/tap and move to adjust the shape of the curve. This approach gives you less direct manipulation, but more control over the full curve’s smoothness.

To create Control Point Splines, follow these steps:

- Define your sketch plane, go to
**Sketch**>**Spline**, then choose**Control**.*For more advanced options for accessing this tool, visit: Accessing tools.* - Draw connecting lines. This creates a polyline that guides the shape of the curve.
- To adjust the curve, select and drag the control points, not the curve itself.
- To add a control point, select the curve and long-tap it.
**To remove a point, select it and tap****Delete**.

Constraints allow you to break or join splines at any point. To break or join splines, select it and then tap the **Break/Join** badge. To connect straight lines with a tangent curve, make sure the spline’s control polyline is in line with the neighboring lines. This will create the curve tangent at these points.

Learn more by watching the video below:

To learn more about constraints, visit Constraints overview. For information on how to edit the dimensions of a sketch, visit Editing sketch dimensions.