Drawing an Equation-Based Surface

Any surface that can be described by an equation in three dimensions can be drawn.

  1. Click Draw > Equation Based Surface.
  2. The Equation Based Surface dialog box opens.

  3. Type equations for X(_u, _v), Y(_u, _v), and Z(_u, _v).
  4. Note:   You can also define an equation by doing the following:
    1. Click the ... button.
      The Edit Equation dialog box appears.
    2. Do one or more of the following to define the equation:
      • Type a numerical value or expression directly in the text box.
      • Select a function to insert from the drop-down menu, and select Insert Function.
      • Select an operator from the drop-down menu, and select Insert Operator.
      • Select a quantity from the drop-down menu, and select Insert Quantity.
    1. When you are finished defining the equation, click OK to close the Edit Equation dialog box and return to the Equation Based Surface dialog box.
    • Any unitless value input in equation based curve is taken as model units. For example, for Y(_t) = 1, the y value is taken as 1 model units (say mm). If a value has units, then it is converted to model units and used. For example, if Y(_t) = 1 cm, then y value will be correctly taken as 10 mm.
    • While parsing expressions, equation based curves convert each variable separately to model units and assume that the resulting expression is in model units.
    • Equation based curves depend on the variable value library to correctly evaluate the units of expression.
  5. Select start values from the Start_u and Start_v drop-down menus.
  6. Select end values from the End_u and End_v drop-down menus. If the Modeler option for editing properties of new primitives is checked, the Properties window appears, in which you can modify the object’s properties.

  7. Click OK on the Properties window.

Related Topics 

Setting the Reference Point

Assigning a Cross Section and Dimension to a Polyline

Drawing an Equation-Based Curve