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Managing curve and broken line shape |
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While creating a spline curve or a broken line it is possible to control its shape by changing the position of the specified points. For a Bezier curve, editing using tangential vectors is also available, and for a spline by points, editing using tangent vector and radius of curvature. All these actions are performed in the editing mode.
Changing the position of the curve and broken line points
To change the position of a point, use the following methods.
•Dragging a point with the mouse.
Click on the desired point and specify its new position.
•Change the coordinates of the point.
Select the required point and enter its coordinates in the cell of the point parameters table or in the field Coordinates. These items are in the group Vertices of the Parameter Panel.
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You can use snaps, and for entering coordinates — geometrical calculator. |
Changing Spline by vertices shape
When constructing a spline by vertices, you can modify its shape by managing the parameters of the tangent vectors at the specified points and/or curvature in these points.
To do this, use the group of buttons Method, allowing you to select the desired option to control the shape of the spline for each point. This group appears in the group Vertices in the Parameter Panel when switching to edit mode.
Step-by-step instructions
1.Specify the desired spline point in the point parameters table on Parameter Panel.
2.Select the method for controlling the shape of the spline at the specified point. To do this, click the desired button of the group Method:
Tangency — allows you to change the length and/or the slope angle of the tangent vector.
Tangency and curvature — allows you to change the length and/or the slope angle of the tangent vector, as well as the curvature.
After selecting the desired method, the fields for setting the corresponding parameters will appear in the Parameter Panel. In the graphics area, next to the specified spline point, the following will be displayed:
•designation of the selected method,
•controlling phantoms:
•for the method Tangency – phantom of the tangent vector,
•for the method Tangency and curvature – phantom of the tangent vector and phantom of the radius of curvature.
At the end of the phantom of the tangent vector are two points. One of the points is used to change the length of the tangent vector, and the other is the angle of its slope.
At the end of the phantom of the radius of curvature there is one point that controls the radius value.
3.Change the shape of the spline at the selected point. To do this, you can:
•enter the required values in the Parameter Panel fields:
•for a tangent vector – its length and slope angle,
•for curvature – curvature or radius of curvature,
•Drag the corresponding points of the control phantoms in the graphics area with the mouse.
4.Similarly, change the shape of the spline at all desired points.
5.If necessary, you can opt out of changing the form made for a specific point. To do this, select this point and click the Not specified 
button in the Method group.
When constructing a Bezier curve, you can change its shape by changing the lengths and/or the angles of inclination of the tangent vectors at the specified points.
Step-by-step instructions
1.Specify the desired curve point in the Point parameters table on the Parameter Panel.
Phantoms of tangent vectors will appear in the graphics area. At the end of each of them there is a point that is used to change the length and angle of the vector.
2.Change the shape of the curve at the selected point. To do this, you can change the parameters of one or both tangent vectors at this point in the following ways:
•specify a point at the end of the desired tangent vector and enter its length and angle of inclination in the fields that appear on the Parameter Panel Tangent Vector Lengthand Tangent Vector Angle,
•Drag the point of the tangent vector phantom in the graphics area with the mouse.
3.Similarly, change the shape of the curve at all desired points.
