Curve Calculator dialog box

Used to place any conceivable curve as a NURBs, based on a mathematical formula. Opens when the Curve Calculator tool is selected in the Curves tool box.

You can set values in the equations that define the curve. The variable-value pairs can be edited as follows:

• Select a row in the list box. The variable and value appear in the text items below the list box.

• Enter a variable's name in its text item and press <Enter>.

• The key-in SET VALUE [variable] [new value] can be used to update a variable-value pair.

The dynamics reflect any changes in the variable-value pairs defining the curve if a placement tool is selected.

Formulas in black are variable-value pairs that can be edited. Formulas that are dimmed are locked and cannot be selected. These are the parametric equations of the curve and should not be changed unless you want to define a new curve (see Defining a Curve's Formula).

For example, the supplied curve definition “Elliptical arc” (in “curve.rsc”) lets you enter values for the two radii that define the ellipse as well as the start and sweep angles.

Tolerance

Sets the tolerance.

Key-in: MDL LOAD CURVCALC

Key-in: ACTIVE TOLERANCE <value>

Curve

Displays the name of the currently loaded curve. The list box below displays the Name and Expression values for variables associated with the displayed curve. You can enter new variables and values in the two text fields directly below this list box.

New

Activates when a new variable is added to the Name text field.

Delete

Activates when a variable is selected in the Name/Expression list box.

File > New File

Lets you remove a curve library and start a new curve library.

Key-in: MDL LOAD CURVCALC

Key-in: MENU NEWFILE

File > Open File

Opens the Resource file to Open dialog box, which is used to open a library of pre-defined curves.

Key-in: MDL LOAD CURVCALC

Key-in: MENU OPENFILE [filename]

By default, looks for “.rsc” files in the directory pointed to by the MS_DATA configuration variable.

File > New Curve

Clears the current curve and values, to let you create a new curve definition.

Key-in: MDL LOAD CURVCALC

Key-in: MENU NEWCURVE

File > Open Curve

Opens the Open Curve Resource dialog box, which is used to select a curve from the open library of pre-defined curves.

Key-in: MDL LOAD CURVCALC

Key-in: MENU OPENCURVE curve number

File > Save

Saves the curve library file.

Key-in: MDL LOAD CURVCALC

Key-in: MENU SAVE

File > Save As…

Opens a dialog box which is used to create a new curve library file.

Key-in: MDL LOAD CURVCALC

Key-in: MENU SAVETO

Edit > Clear

Removes the listed curve from curve library. All equations are removed and the defaults are set for tolerance, units, angle, and mode.

Key-in: MDL LOAD CURVCALC

Key-in: MENU CLEAR

Edit > Duplicate

Lets you duplicate the currently selected curve, giving it a new name. This makes it easy to define a new curve from an old curve without having to re-type all the equations.

Key-in: MDL LOAD CURVCALC

Key-in: MENU DUPLICATE

Edit > Angles

Lets you set the Active Angle Units to either Degrees or Radians.

Key-in: MDL LOAD CURVCALC

Key-in: ACTIVE ANGLES <DEGREES | RADIANS>

Edit > Mode

Sets the type of curve or linestring to create.

Curve type	Specified	Created using
Defined	Completely by equations	Place Parametric Curve, or Place Parametric Linestring
Derived	By equations and a root curve	Construct Parametric Curve, or Construct Parametric Linestring

A curve's type is stored in the library file so that the appropriate create commands can be enabled when the curve is loaded.

Key-in: MDL LOAD CURVCALC

Key-in: ACTIVE MODE [DEFINED | DERIVED]

Tools > Place Parametric Curve

(Edit > Mode set to Defined only) Used to place a curve that is defined by listed formulas relative to a view's coordinate system.

The active units, active angle, and Tolerance are set in the Curve Calculator dialog box.

Key-in: MDL LOAD CURVCALC

Key-in: PLACE PARAMETRIC CURVE RELATIVE

To place a curve that is defined by listed formulas relative to the design file coordinate system, key-in PLACE PARAMETRIC CURVE ABSOLUTE.

Tools > Place Parametric Line String

(Edit > Mode set to Defined only) Used to place a line string that is defined by listed formulas relative to a view's coordinate system. The vertices are evaluated at even intervals throughout the domain of the equations. By default, 11 vertices are calculated at the values t = 0.0, 0.1, 0.2,…,1.0.

The active units, active angle, and Tolerance are set in the Curve Calculator dialog box.

Key-in: MDL LOAD CURVCALC

Key-in: PLACE PARAMETRIC LINESTRING RELATIVE number_of_vertices

To place a line string that is defined by listed formulas relative to the design file coordinate system, key in PLACE PARAMETRIC LINESTRING ABSOLUTE number_of_points.

Tools > Construct Parametric Curve

(Edit > Mode set to Derived only) Used to place a curve defined by the listed formulas and a curve in the design. Offsets and evolutes are examples of such curves.

The active units, active angle units, and Tolerance are set in the Curve Calculator dialog box.

Key-in: MDL LOAD CURVCALC

Key-in: CONSTRUCT PARAMETRIC CURVE

Tools > Construct Parametric Line String

(Edit > Mode set to Derived only) Used to create a curve defined by the listed formulas and a curve in the design. The vertices are evaluated at even intervals throughout the domain of the equations. By default, 11 vertices are calculated at the values t = 0.0, 0.1, 0.2,…,1.0.

The active units, active angle, and Tolerance are set in the Curve Calculator dialog box.

Key-in: MDL LOAD CURVCALC

Key-in: CONSTRUCT PARAMETRIC LINESTRING <number_of_vertices>