More Spline-editing Tips

Adding to a finished spline (2-dimensional line):

1. Using the Select Object tool, right-click on the finished spline and Convert To... -> Convert to Editable Spline.
2. Under the Modify tab, choose Vertex sub-selection mode.
3. Scroll down until you find the End Point Auto-welding section. Check next to Automatic Welding.
4. Above that, in the Geometry section, turn on Create Line.
5. Hover over the vertex on the line from which you want to continue. Your mouse pointer should change. Click on it to continue your line.

To add points in the middle of a spline, in the Modify tab under Geometry, turn on Refine.

Subtract points by selecting them and hitting Delete on your keyboard.