# How to calculates a point on a curve at x value by rvb?

How to calculates a point on a curve at x value by rhinoscript?

Maybe something like this?

``````Option Explicit
'Version 4 February, 2015

Call FindIntersectPointsOnCurve()
Sub FindIntersectPointsOnCurve()
Dim crvID, xVal

crvID = Rhino.GetObject("Select curve", 4, True)
If IsNull(crvID) Then Exit Sub

xVal = Rhino.GetReal("Value along x axis to test?", 0.0)
If IsNull(xVal) Then Exit Sub

Dim plane, insec, i, ptStr, msg
plane = Rhino.WorldYZPlane()
plane(0) = Array(xVal, 0, 0)
insec = Rhino.PlaneCurveIntersection(plane, crvID)

If IsArray(insec) Then
msg = ""
For i=0 To Ubound(insec)

If insec(i, 0) = 1 Then
ptStr = Rhino.Pt2Str(insec(i, 1))
msg = msg & "Intersection point found at " & ptStr & vbNewline
Else
msg = msg & "Part of curve parallel to Y axis at " & Cstr(xVal) & vbNewLine
End If
Next
Call Rhino.MessageBox(msg)
Else
Call Rhino.Print("Curve does not go through X=" & Cstr(xVal))
End If
End Sub
``````
1 Like

Code worked.Thanks.

Of course, this is much more fun to do in Grasshopperâ€¦

1 Like