Adding Features - Reference Circle

📝 Overview

The Reference Circle option is available in the Snap menu when adding or editing symbols and polylines.

It allows you to:

• Place a circle (with a specified radius if required).

• Fix a point on the circumference, ensuring it is a set distance from a pre-defined point.

This provides a convenient way to:

• Place a symbol (e.g. accident sign at a given distance from a junction).

• Add a public notice at a set distance from an application or incident site.

• Set out a line at a fixed offset from another line.

---

📍 Example: Adding Points at Equal Distance from a Known Location

1. Begin adding a new feature.

   • Right-click to display the menu containing the Reference Circle option.

   • This can be done at any time during the drawing process — even before the first point is added.

   • For example: choose Add → Symbol and right-click immediately.

2. Left-click the point you want to be the centre of the reference circle.

3. Drag out the circle with the mouse.

   • Left-click again to fix the circle.

   • For a precise distance, right-click during this operation, select Radius, and enter the required value.

   • The circle will be drawn automatically at the specified distance.

---

🎯 Snapping to the Reference Circle

• When you next click to add a new symbol (or a point along a polyline/polygon) and you are within the search tolerance of the circle:

  • The point will snap to the circle.

  • A ‘Snap to reference circle’ box will appear, confirming the action.

➡️ Select Yes to add the point on the circle.
➡️ Select No to discard it.

⚠️ Warning: If you accidentally add a snapped point you don’t need, use Undo to remove it.

---

🔄 Working with Other Points

• You can add other points not on the circle and later return to use the circle again.

• The reference circle temporarily acts like any other snap-enabled feature and will remain available until you click Finish.

❌ Important: Do not try to use the Snap function itself from the Right-button menu while the reference circle is visible. This will result in “no features found”, even if you attempt to snap to the reference circle.

---

🛠️ Editing with Reference Circle

The Reference Circle can also be used when editing graphics, such as relocating a symbol:

1. Select the existing graphic.

2. Follow the same procedure to create a reference circle.

3. Snap the symbol’s new position to the circle as required.