How do you add a vertex in Altium polygon?

To add a vertex to an existing polygon in Altium Designer, use the "Modify Polygon Border" command.

Here's a step-by-step guide:

1. Right-click on the polygon you want to modify.
2. From the context menu, select Polygon Actions » Modify Polygon Border.
3. The cursor will change to a crosshair.
4. Click at the desired location on the polygon border where you want to insert a new vertex. Each click will add a new vertex.
5. While adding vertices, you can change the corner style using the Shift+Spacebar keys, cycling through modes like mitered, rounded, and arc.
6. Right-click again or press Esc to exit the "Modify Polygon Border" command and finalize the changes.

By following these steps, you can precisely add vertices to your Altium polygon and adjust its shape as needed.