Curve Equation (3D) - Drawing Function-controlled Curves
General
- You can use curve equations to draw function-controlled curves (splines).
- The use of this function is based on specifying the start and end points and defining an equation which the curve between the points will follow.
- Enter the value of the angle in radians.
- For example a band-like object is easy to create.
Add a curve using the equation editor
- Select the context-sensitive function Line > Curve Equation.
- Enter the spline line feature values in the Equation Editor.
- Enter the X function.
- Enter the Y function.
- Enter the coordinates of the start point of the curve.
- Enter the coordinates of the end point of the curve.
Define the equations in parametric format as functions of t X(t) and Y(t).- For example the equation Y=X**2 (i.e. X to the power of 2)
- X(t) = t
- Y(t) = t**2 (i.e. t to the power of 2)
- If the data specified in the dialog box is sensible, the Preview button is enabled and you can click it.
- Click OK to accept the curve or
- Click Cancel to cancel the drawing of the curve.
Example 1: Parabola
A parabola curve passing through three points (-50,0),(0,50)(50,0) can be defined in the dialog box as follows:
The same parabola could also be defined as follows:
- X(t) = t
- Y(t) = -0.02*(t**2)+50.0
- t-start = -50
- t-end = 50
Example 2: A cosine curve
- X(t) = t
- Y(t) = 20*cos(t)
- t-start = -6
- t-end = 6
If the data specified in the dialog box is sensible, the Preview button is enabled and you can click it.
Example 3: An equation for a hanging rope.
Editing a Curve
You can add a curve added with a curve equation as follows.
- Select the curve.
- Select the context-sensitive function Curve Equation.
- Edit curve data in the dialog box.
- Select OK.