How to draw a curve

Draw a Curve allows you to draw smooth curves on the GNS3 network topology map for creating curved paths or connection markers.

Quick Start

Activate the Tool

Click the curve icon button on the toolbar (tooltip: "Draw a curve"). The mouse cursor will change to a crosshair.

Drag to Draw

Press and hold the mouse button on the map and drag to create a curve path. Release the mouse button to complete the drawing. The curve is automatically saved to the server.

Style Editor

Right-click on the curve and select Edit style to open the Style editor dialog.

• Border Color — Color picker
• Border Width — Numeric input (range: 0–100)
• Border Style — 6 options: Solid, Dash, Dot, Dash Dot, Dash Dot Dot, No border
• Curve Type — 3 options:
  • Catmull-Rom (Smooth, default) — Smooth curve passing through all points
  • Basis (B-spline) — Smoother but may not pass through all points
  • Monotone — Monotonic curve to avoid oscillation
• Arrow Direction — 4 options: No Arrow, End Arrow, Start Arrow, Both Arrows
• Rotation — Numeric input for rotation angle

Curve Example

Dialog Buttons

• Cancel — Discard changes
• Apply — Save changes

Comparison with Other Drawing Tools

Feature	Rectangle / Ellipse / Line	Curve
Drawing method	Click to create	Drag to create
Tool state	Stays active	Auto exits
Creation path	Single point	Multi-point path
Curve type	N/A	3 options