Hi everyone,

I am trying to test the RhinoCommon MeshLine Intersetion command on a simple example but it seems that this function is missing some intersection points.

I have a valid manifold planar mesh where all the faces have the same orientation and I try to find the intersection points with 3 lines as shown in the following picture (I highlighted this missing intersection points with black rectangles):

So please I want to know if I’m not using this command in the right way or if this is a bug. Please find below the script I used for this test and the input mesh (the mesh is in OFF format so to read it using Rhino, simply change the extension of the file from “.txt” to “.OFF” and then import it using Rhino “Import” command). Thank you in advance for your help.

`Dim att As DocObjects.ObjectAttributes = New DocObjects.ObjectAttributes With {.ColorSource = Rhino.DocObjects.ObjectColorSource.ColorFromObject}`

`Dim mesh As Geometry.Mesh = Nothing : mesh.GetFromDocument() If mesh Is Nothing Then Return Result.Nothing mesh.UnifyNormals()`

`Dim P11 As New Geometry.Point3d(-4.0, -4.0, 0.0) Dim P12 As New Geometry.Point3d(-4.0, 4.0, 0.0)`

`Dim line1 As New Geometry.Line(P11, P12) att.ObjectColor = Drawing.Color.Red doc.Objects.AddLine(line1, att)`

`Dim intPts1 As Geometry.Point3d() = Geometry.Intersect.Intersection.MeshLine(mesh, line1, Nothing) For i As Integer = 0 To intPts1.Length - 1 doc.Objects.AddPoint(intPts1(i)) Next`

`Dim P21 As New Geometry.Point3d(-3.0, -4.0, 0.0) Dim P22 As New Geometry.Point3d(-3.0, 4.0, 0.0)`

`Dim line2 As New Geometry.Line(P21, P22) att.ObjectColor = Drawing.Color.Blue doc.Objects.AddLine(line2, att)`

`Dim intPts2 As Geometry.Point3d() = Geometry.Intersect.Intersection.MeshLine(mesh, line2, Nothing) For i As Integer = 0 To intPts2.Length - 1 doc.Objects.AddPoint(intPts2(i)) Next`

`Dim P31 As New Geometry.Point3d(-1.5, -4.0, 0.0) Dim P32 As New Geometry.Point3d(-0.5, 4.0, 0.0)`

`Dim line3 As New Geometry.Line(P31, P32) att.ObjectColor = Drawing.Color.Green doc.Objects.AddLine(line3, att)`

`Dim intPts3 As Geometry.Point3d() = Geometry.Intersect.Intersection.MeshLine(mesh, line3, Nothing) For i As Integer = 0 To intPts3.Length - 1 doc.Objects.AddPoint(intPts3(i)) Next`

`doc.Views.Redraw()`

Test.txt (586 Bytes)