The Draw Spline tool creates splines in the Level Editor. You can use your created splines with the Revolve Spline and Mesh Splines modeling tools to create meshes, or with custom blueprint actors to create a variety of objects such as rails or vines.
To learn more about other spline workflows, see the following:
You can edit splines outside of the tool by selecting and manipulating points on the spline, right-clicking the spline, or using the Details panel.
Accessing the Tool
You can access the Draw Splines tool from the Create category in Modeling Mode. To learn more about Modeling Mode and how to access it, see Modeling Mode Overview.
Using Draw Spline
To create a spline, follow these steps:
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Choose an output type for the spline from the Output Mode dropdown.
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Choose how to draw your spline from the Draw Mode dropdown.
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Click or drag in the level to draw your spline.
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Accept or cancel the changes in the Tool Confirmation panel.
Output Mode
Output Mode determines how a spline component is created.
| Output Mode | Description |
|---|---|
| Empty Actor | Creates an empty actor with a spline component. |
| Existing Actor | Attaches the spline component to an existing actor or replaces a spline inside that actor if Existing Spline Index To Replace is valid. To choose an existing actor, click the actor before switching the mode or use the eyedropper to choose. |
| Create Blueprint | Creates the Blueprint specified by Blueprint To Create and attaches the spline to that, or replaces an existing spline in the created object if Existing Spline Index To Replace is valid. |
If you are working with a blueprint actor that has an expensive construction script, it can be helpful to turn off Rerun Construction Script on Drag under advanced options.
Draw Mode
To adjust how the spline is drawn in the scene, use the properties in the Draw Mode section. You can switch between the modes while creating a spline in the level.
| Draw Mode | Description | Example |
|---|---|---|
| Tangent Drag | Draws a spline point by point with manual control over curvature (via tangents). Click to place a point and drag to set its tangent. Clicking without dragging creates sharp corners. |  |
| Click Auto Tangent | Draws a spline point by point with curvature automatically set. Click and drag to place new points, with the tangent set automatically. |  |
| Free Draw | Draws a spline with a freehand motion. Click and drag to place multiple points, with spacing controlled by Min Point Spacing. |  |
To have an open or closed path you can toggle Loop. When true, points continue to append to the loop as you draw onto it. To help visualize the path and rotation, increase the Frame Visualization Width value.
Raycast Targets
The Raycast Targets section determines how the mouse location interacts with the scene while drawing a spline. You can toggle multiple options at the same time.
You must have at least one option enabled to draw a spline.
| Raycast Targets | Description | Example |
|---|---|---|
| World | Splines are drawn on mesh surfaces in the level, except the target mesh when Existing Actor is enabled. |  |
| Custom Plane | Splines are drawn on a plane that you can reposition with the gizmo or with Ctrl + Click. |  |
| Ground Planes | Splines are drawn on the XY ground plane in the perspective viewport, or on the viewed plane in orthographic viewports. |  |
Hotkeys
| Hotkey | Description |
|---|---|
| C | Zooms into the location of the mouse. |
| Enter | Accepts tool changes. |
| ESC | Cancels the changes and exit the tool. |
