GetTangent Method

Description

Computes the unit-vector tangent at each of the points, given an array of parameter values on the curve.

Syntax

Visual Basic
Public Sub GetTangent( _ ByVal NumParams As Long, _ ByRef Params() As Double, _ ByRef Tangents() As Double _ )

Parameters

NumParams: Specifies the number of parameters to be evaluated.
Params: Specifies the array of parameters to be evaluated.
Tangents: Specifies the array of unit tangent vectors in the logical flow direction.

Remarks

The tangent is always pointed in the direction of the logical flow of the curve. If no inherent logical flow can be assigned (as in the case of an Edge shared by two Faces), the direction is the direction of increasing parameterization.

Example

Example (Visual Basic)

Private Sub Form_Load()
    Dim objApp As SolidEdgeframework.Application
    Dim objDoc As SolidEdgePart.PartDocument
    Dim objLoops As Object
    Dim objEdgeUse As solidedgegeometry.EdgeUse
    Dim dblParams(1 To 2) As Double
    Dim dblTangents() As Double
    Const TESTFILE = "T:\vbtests\testcases\cube.par"
    ' Report errors
    Const PI = 3.14159265358979
    ' Create/get the application with specific settings
    On Error Resume Next
    Set objApp = GetObject(, "SolidEdge.Application")
    If Err Then
        Err.Clear
        Set objApp = CreateObject("SolidEdge.Application")
        Set objDoc = objApp.Documents.Add("SolidEdge.PartDocument")
        objApp.Visible = True
    Else
        Set objDoc = objApp.ActiveDocument
    End If
    Call objDoc.Close
    ' opening the test case file
    Set objDoc = objApp.Documents.Open(TESTFILE)
    ' getting the collection of loops from the body object in the model
    Set objLoops = objDoc.Models(1).Body.Faces(FaceType:=igQueryAll).Item(5).Loops
    ' getting an EdgeUse object for a loop
    Set objEdgeUse = objLoops.Item(1).EdgeUses.Item(2)
    ' getting the tangents at a point for an EdgeUse object
    dblParams(1) = 0.5
    dblParams(2) = 0.75
    Call objEdgeUse.GetTangent(NumParams:=2, Params:=dblParams, Tangents:=dblTangents)
    ' USER DISPLAY
    ' Release objects
    Set objApp = Nothing
    Set objDoc = Nothing
    Set objLoops = Nothing
    Set objEdgeUse = Nothing
End Sub