Issue
Parameterization is not uniform, a linear sequence in parameter space would not necessarily correspond to a uniform spacing in model space (in general it is not).If you want even spacing in model space, use GetParamAtLength (iteratively).
Solution
The sample VBA code shown below demonstrates the same. The sample code assumes that you have a spline in part sketch.
Sub geteqdistptAss()
' assume we have had Inventor application
Dim oDoc As PartDocument
oDoc = _InvApplication.ActiveDocument
Dim oTG As TransientGeometry
oTG = _InvApplication.TransientGeometry
Dim oDef As PartComponentDefinition
oDef = oDoc.ComponentDefinition
Dim oSketch As PlanarSketch
oSketch = oDef.Sketches(1)
' Get the spline on a planar sketch
Dim oSpline As SketchSpline
oSpline = oSketch.SketchSplines(1)
Dim oEval As Curve2dEvaluator
oEval = oSpline.Geometry.Evaluator
Dim dmin As Double
Dim dmax As Double
oEval.GetParamExtents(dmin, dmax)
' Get the curve length
Dim dLen As Double
Call oEval.GetLengthAtParam(dmin, dmax, dLen)
Dim dInc As Double
dInc = dLen / 100 'consider 100 points
Dim dLenInc As Double
dLenInc = 0
Dim dparams(0) As Double
dparams(0) = dmin
Dim iCnt As Integer
For iCnt = 0 To 100
Dim dParam As Double
Call oEval.GetParamAtLength(dmin,
dLenInc,
dParam)
' a spline in planar sketch is 2d. its points are
‘ 2d (x,y)
Dim dPts(1) As Double
dparams(0) = dParam
Call oEval.GetPointAtParam(dparams, dPts)
dmin = dParam
Dim oPt2d As Point2d
oPt2d = oTG.CreatePoint2d(dPts(0), dPts(1))
Dim oPt3d As Point
oPt3d = oSketch.SketchToModelSpace(oPt2d)
'add the point as a work point
oDef.WorkPoints.AddFixed(oPt3d, False)
dLenInc = dLenInc + dInc
Next
End Sub
