Draw Curve

Function Description

Application supports a variety of curves, such as Bezier Curve, B-Spline Curve, Cardinal Curve, Free Curve, and Geodesic Curve.

Function entrance

  • Object Operation tab-> Object Drawing group-> Line drop-down box-> Curve.

Operating instructions

Draw a Bezier Curve

Bezier Curve uses two Start Nodes and two End Nodes that are not on the curve to control the direction of the curve, and uses other control points on the curve to fit the middle points of the curve. At least 6 control points are required to draw a Bezier Curve.

  1. On the Object Operation tab, in the Object Drawing group, click the Line Drop-down Button and select the Bezier Curve option. The Bezier Curve cursor appears.
  2. Move Stop by Mouse to Map, and you can see that the coordinate value of the current mouse position will be displayed in the Parameter Input box in real time as the mouse moves. Enter the coordinate value of the first control point of the Bezier Curve in the Parameter Input box (you can switch between the two Parameter Input boxes by pressing the Tab key), and then press the Enter key to confirm.
  3. Enter the coordinates of the second to fourth control points in the same way. The coordinates of the first four control points determine the direction of the Bezier Curve.
  4. Enter the coordinates of the fifth control point on the curve, and a blue dashed line appears between the third and fourth control points, which is the first segment of the fit on the Bezier Curve.
  5. Continue to enter the coordinates of the sixth control point and draw the second segment of the Bezier Curve.
  6. Repeat the previous step to continue drawing other lines of the Bezier Curve.
  7. Right-click to end the current drawing.

B-spline curve

B-Spline Curve is drawn by the first two control points on the curve and the middle control points not on the curve. The other points on the curve are fitted according to the middle control points on the curve. At least 4 control points are required to complete the drawing of a B-Spline Curve.

  1. On the Object Operation tab, in the Object Drawing group, click the Line Drop-down Button and select the B-Spline Curve option. The B-Spline Curve cursor appears.
  2. Move Stop by Mouse to Map, and you can see that the coordinate value of the current mouse position will be displayed in the Parameter Input box in real time as the mouse moves. Enter the coordinate value of the first control point of the curve in the Parameter Input box (you can switch between the two Parameter Input boxes by pressing the Tab key) and confirm by pressing the Enter key.
  3. Enter the coordinates of the second control point on the curve.
  4. Enter the coordinates of the third control point on the curve. A blue dashed line appears between the second and third control points, representing the first segment of the B-Spline Curve.
  5. Enter the coordinates of the fourth control point on the curve. A blue dashed line appears between the third and fourth control points, representing the second segment of the B-Spline Curve.
  6. Repeat the previous step to continue drawing other segments of the B-Spline Curve.
  7. Right-click to end the current drawing.

Cardinal curve

The Cardinal curve is drawn by determining the control points on the curve, and the other points of the curve are fitted according to all the control points. At least 3 control points are required to complete the drawing of a segment of Cardinal curve.

  1. On the Object Operation tab, in the Object Drawing group, click the Line Drop-down Button and select the Cardinal Curve option. The Cardinal curve cursor appears.
  2. Move Stop by Mouse to Map, and you can see that the coordinate value of the current mouse position will be displayed in the Parameter Input box in real time as the mouse moves. Enter the coordinate value of the first control point of the curve in the Parameter Input box (you can switch between the two Parameter Input boxes by pressing the Tab key) and confirm by pressing the Enter key.
  3. Enter the second control point in the same way, and you can see a blue dotted line between the two points.
  4. Move the mouse, enter the coordinates of the third control point, and you can see the second blue dotted line between the second control point and the third control point.
  5. Right-click to end the current drawing.

Free Curve

Free Curve a curve obtained by freely dragging Draw. Drawing a Free Curve is useful when creating irregular boundaries or tracing with a digitizer.

  1. On the Object Operation tab, click the Line Drop-down Button in the Object Drawing group and select the Free Curve option. The Free Curve cursor appears.
  2. Move the cursor to the position where the Free Curve is created, click the left mouse button, hold the left mouse button, and move the mouse to draw a curve on the map consistent with the cursor movement track.
  3. When you finish drawing, right-click to end the operation.

Geodesic

A geodesic is a curve in the radian of the earth's surface that most accurately represents the shortest distance between any two points on the earth's surface. It is often used to draw global navigation or aviation routes. It is necessary to open Global Pan to draw geodesic lines.

The following is a detailed description of the operation steps of this function by taking the drawing of air routes as an example:

  1. Open the World. Smwu Workspace in Sample Data, open the "World Map _ Day" "in Map, and open the editable line data in Line DatasetAdd to Map.
  2. On the Object Operation tab, in the Object Drawing group, click the Line Drop-down Button, select the Geodesic Line option, and move the mouse to the map to start drawing.
  3. Click to the left of the start and end points of the route, and then right-click to end the currently drawn line object. After drawing, set Layer Style to get the following result figure:
Figure: Route map