How to get parameter value of a sketch 3D point - GetParamAtPoint() does not work well?

[liminma8458]

Hi, experts,

It is a 3D spline in a sweep which has non-evenly distributed sketch points in it. I want to extract parameter values (in parameter space) of these sketch points. I try to use "CurveEvaluator.GetParamAtPoint Method". But It does not work through. See the code below and the part is attached.

Please help! Thank you very much!

Public Sub Curve_evaluator()

'On Error Resume Next
Dim oSpline3D As SketchSpline3D

Set oSpline3D = ThisApplication.CommandManager.Pick(kSketch3DCurveSplineFilter, "Select a sketch 3D Spline. Esc to quit.")

'----go through each point and get its parameter
Dim oFitPoint_Count As Integer
oFitPoint_Count = oSpline3D.FitPointCount

Dim oParam() As Double
ReDim oParam(1 To oFitPoint_Count) As Double

' Get the evaluator from the curve.
Dim oCurveEval As CurveEvaluator
'Set oCurveEval = oEdge.evaluator
Set oCurveEval = oSpline3D.Geometry.evaluator

' Get the parametric range of the curve.
Dim dMinParam As Double
Dim dMaxParam As Double
Call oCurveEval.GetParamExtents(dMinParam, dMaxParam)
Debug.Print vbCr & "dMinParam : " & dMinParam & vbCr & "dMaxParam : " & dMaxParam

Dim currentParam As Double
Dim i As Integer
For i = 1 To oFitPoint_Count

currentParam = dMinParam + ((dMaxParam - dMinParam) / oFitPoint_Count) * (i - 1)

Dim fst_point(2) As Double
Dim fst_param(0) As Double
Dim deviate_param(0) As Double
Dim sec_param(0) As Double
Dim sol_param(0) As SolutionNatureEnum

fst_param(0) = currentParam - 0.2

fst_point(0) = oSpline3D.FitPoint(i).Geometry.x
fst_point(1) = oSpline3D.FitPoint(i).Geometry.y
fst_point(2) = oSpline3D.FitPoint(i).Geometry.Z

'----There is problem with this line when runing---

Call oCurveEval.GetParamAtPoint(fst_point, fst_param, deviate_param, sec_param, sol_param)
oParam(i) = fst_param(0)

Debug.Print "currentParam: " & Format(currentParam, "0.00") & _
" first_param: " & Format(fst_param(0), "0.00") & _
" first_point: " & Format(fst_point(0), "0.00") & "," & _
Format(fst_point(1), "0.00") & "," & _
Format(fst_point(2), "0.00") & _
" second_param: " & Format(sec_param(0), "0.00") & _
" solution_no: " & Format(sol_param(0), "0.00")

Next i

End Sub

[JelteDeJong]

this is how i would do it in ilogic

Dim doc As PartDocument = ThisDoc.Document

Dim oSpline3D As SketchSpline3D = ThisApplication.CommandManager.Pick(SelectionFilterEnum.kSketch3DCurveSplineFilter, "Select a sketch 3D Spline. Esc to quit.")

For i = 1 To oSpline3D.FitPointCount
    Dim sketchPoint3D As SketchPoint3D = oSpline3D.FitPoint(i)
    Dim geo As Point = sketchPoint3D.Geometry

    Logger.Info(String.Format("{0} - {1} - {2}", geo.X, geo.Y, geo.Z))
Next

[liminma8458]

Hi, Jone,

Thanks

I am not looking for the coordinate information of the sketch points. Instead, I am looking for the parameter value of these points in the parametric space on the spline edge. something like below:

[YuhanZhang · Accepted solution]

:The output array needs not to be declared with size, so the code can be modified as below:

Public Sub Curve_evaluator()

'On Error Resume Next
Dim oSpline3D As SketchSpline3D

Set oSpline3D = ThisApplication.CommandManager.Pick(kSketch3DCurveSplineFilter, "Select a sketch 3D Spline. Esc to quit.")

'----go through each point and get its parameter
Dim oFitPoint_Count As Integer
oFitPoint_Count = oSpline3D.FitPointCount

Dim oParam() As Double
ReDim oParam(1 To oFitPoint_Count) As Double

' Get the evaluator from the curve.
Dim oCurveEval As CurveEvaluator
'Set oCurveEval = oEdge.evaluator
Set oCurveEval = oSpline3D.Geometry.Evaluator

' Get the parametric range of the curve.
Dim dMinParam As Double
Dim dMaxParam As Double
Call oCurveEval.GetParamExtents(dMinParam, dMaxParam)
Debug.Print vbCr & "dMinParam : " & dMinParam & vbCr & "dMaxParam : " & dMaxParam

Dim currentParam As Double
Dim i As Integer
For i = 1 To oFitPoint_Count

currentParam = dMinParam + ((dMaxParam - dMinParam) / oFitPoint_Count) * (i - 1)

Dim fst_point(2) As Double
Dim fst_param(0) As Double
'Dim deviate_param(0) As Double
'Dim sec_param(0) As Double
'Dim sol_param(0) As SolutionNatureEnum


Dim deviate_param() As Double
Dim sec_param() As Double
Dim sol_param() As SolutionNatureEnum

fst_param(0) = currentParam - 0.2

fst_point(0) = oSpline3D.FitPoint(i).Geometry.X
fst_point(1) = oSpline3D.FitPoint(i).Geometry.Y
fst_point(2) = oSpline3D.FitPoint(i).Geometry.Z

 

'----There is problem with this line when runing---

Call oCurveEval.GetParamAtPoint(fst_point, fst_param, deviate_param, sec_param, sol_param)
oParam(i) = fst_param(0)

Debug.Print "currentParam: " & Format(currentParam, "0.00") & _
" first_param: " & Format(fst_param(0), "0.00") & _
" first_point: " & Format(fst_point(0), "0.00") & "," & _
Format(fst_point(1), "0.00") & "," & _
Format(fst_point(2), "0.00") & _
" second_param: " & Format(sec_param(0), "0.00") & _
" solution_no: " & Format(sol_param(0), "0.00")

Next i

End Sub

[liminma8458]

Perfect! Thank you so much!

[Stakin]

Hi,

Is there a way to get the BsplineCurve fitpointData of a BSplineSurface?

After obtain the BsplineCurve fitpointdata,is there a way to  recreate the SplineCurve in the sketch3d ?