Solder mask cutouts can be polygonal with optional curved edges. To change to curved cutout click on the Curve tab in the cutouts properties in the properties panel.
To edit the parameters of a cutout, first select it. The properties panel will display the properties for the selected cutout.
Click the button to show this help topic.
This is the selected vertex/segment. The selected vertex is drawn as a solid red square. The selected segment id drawn in red.
The X coordinate of the selected vertex.
The Y coordinate of the selected vertex.
Slide the slider to change the 'curvature' of the curve.
Click to add a vertex.
Click to delete the selected vertex.
Check the Smooth button to smooth the entire curve.
Check the Straight button to straighten the entire curve.
Check the Editable button to make the entire curve editable.
Click the button to straighten the selected segment.
Click the button to smooth the selected segment.
Use this drop-down to set the layer for the rectangle.
Click to fillet the polygon
Drag any of the control points to change the shape.
Uncheck the button to make the control points for the vertex independent of each other.