# Divide a curve using equi-distance points

Developer: RhinoScript
Summary: Demonstrates equi-distance curve division using RhinoScript

## Summary

Rhino's Divide command divides a curve based on arc length, or the distance along the curve between two points. This RhinoScript sample divides a curve based on the distance (linear) between points.

``` Option Explicit

''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' ''''''''''
' Description
'   Divides a curve based on the linear distance between points.
'
Sub DivideCurveEquiDistant

Dim crv
crv = Rhino.GetObject("Select curve to divide", 4, True)
If IsNull(crv) Then Exit Sub

Dim crv_length
crv_length = Rhino.CurveLength(crv)

Dim length
length = Rhino.GetReal("Curve length is " & CStr(crv_length) & ". Division length", 1.0)
If Not IsNumeric(length) Then Exit Sub

If (crv_length < length) Then
Rhino.Print "Specified divison length exceeds curve length."
Exit Sub
End If

Rhino.EnableRedraw False

Dim dom, t, pt
dom = Rhino.CurveDomain(crv)
t = dom(0)
pt = Rhino.EvaluateCurve(crv, t)
Rhino.AddPoint pt

Dim bDone: bDone = False
While (bDone = False)
t = EquiDistantParameter(crv, t, length)
If IsNull(t) Then
bDone = True
Else
pt = Rhino.EvaluateCurve(crv, t)
Rhino.AddPoint pt
End If
Wend

Rhino.EnableRedraw True

End Sub

'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
' Description
'   Finds the parameter on a curve that is a specified
'   linear distance from a known parameter.
'
Function EquiDistantParameter(crv, t, length)

EquiDistantParameter = Null

Dim pt
pt = Rhino.EvaluateCurve(crv, t)

Dim sphere
sphere = Rhino.AddSphere(pt, length)

Dim csx
csx = Rhino.CurveSurfaceIntersection(crv, sphere)

Rhino.DeleteObject sphere
If Not IsArray(csx) Then Exit Function

Dim i
For i = 0 To UBound(csx)
If csx(i,0) = 1 Then
If (csx(i,5) > t) Then
EquiDistantParameter = csx(i,5)
Exit Function
End If
End If
Next

End Function```

developer/scriptsamples/divideequidistance.txt ยท Last modified: 2020/08/14 (external edit)