McNeel Wiki

public static Rhino.Commands.Result UnrollSurface2(Rhino.RhinoDoc doc)
{
  const ObjectType filter = Rhino.DocObjects.ObjectType.Brep | Rhino.DocObjects.ObjectType.Surface;
  Rhino.DocObjects.ObjRef objref;
  Result rc = Rhino.Input.RhinoGet.GetOneObject("Select surface or brep to unroll", false, filter, out objref);
  if (rc != Rhino.Commands.Result.Success)
    return rc;
  Rhino.Geometry.Unroller unroll=null;
  Rhino.Geometry.Brep brep = objref.Brep();
  Rhino.Geometry.Mesh mesh=null;
  if (brep != null)
  {
    unroll = new Rhino.Geometry.Unroller(brep);
    mesh = brep.Faces[0].GetMesh(Rhino.Geometry.MeshType.Render);
  }
  else
  {
    Rhino.Geometry.Surface srf = objref.Surface();
    if (srf != null)
    {
      unroll = new Rhino.Geometry.Unroller(srf);
    }
  }
  if (unroll == null || mesh==null)
    return Rhino.Commands.Result.Cancel;
 
  unroll.AddFollowingGeometry(mesh.Vertices.ToPoint3dArray());
 
  unroll.ExplodeOutput = false;
  Rhino.Geometry.Curve[] curves;
  Rhino.Geometry.Point3d[] points;
  Rhino.Geometry.TextDot[] dots;
  unroll.PerformUnroll(out curves, out points, out dots);
 
  // change the mesh vertices to the flattened form and add it to the document
  if( points.Length == mesh.Vertices.Count )
  {
    for( int i=0; i<points.Length; i++ )
      mesh.Vertices.SetVertex(i, points[i]);
    mesh.Normals.ComputeNormals();
  }
  doc.Objects.AddMesh(mesh, objref.Object().Attributes);
  doc.Views.Redraw();
  return Rhino.Commands.Result.Success;
}

Public Shared Function UnrollSurface2(ByVal doc As Rhino.RhinoDoc) As Rhino.Commands.Result
  Dim rc As Rhino.Commands.Result
  Const filter As ObjectType = Rhino.DocObjects.ObjectType.Brep Or Rhino.DocObjects.ObjectType.Surface
  Dim objref As Rhino.DocObjects.ObjRef = Nothing
  rc = Rhino.Input.RhinoGet.GetOneObject("Select surface or brep to unroll", False, filter, objref)
  If rc <> Rhino.Commands.Result.Success Then
    Return rc
  End If
  Dim unroll As Rhino.Geometry.Unroller = Nothing
  Dim brep As Rhino.Geometry.Brep = objref.Brep()
  If brep IsNot Nothing Then
    unroll = New Rhino.Geometry.Unroller(brep)
  Else
    Dim srf As Rhino.Geometry.Surface = objref.Surface()
    If srf IsNot Nothing Then
      unroll = New Rhino.Geometry.Unroller(srf)
    End If
  End If
  If unroll Is Nothing Then
    Return Rhino.Commands.Result.Cancel
  End If
 
  Dim mesh As Rhino.Geometry.Mesh = brep.Faces(0).GetMesh(Rhino.Geometry.MeshType.Render)
  If mesh Is Nothing Then
    Return Rhino.Commands.Result.Cancel
  End If
 
  unroll.AddFollowingGeometry(mesh.Vertices.ToPoint3dArray())
 
  unroll.ExplodeOutput = False
  Dim curves As Rhino.Geometry.Curve() = Nothing
  Dim points As Rhino.Geometry.Point3d() = Nothing
  Dim dots As Rhino.Geometry.TextDot() = Nothing
  unroll.PerformUnroll(curves, points, dots)
 
  ' change the mesh vertices to the flattened form and add it to the document
  If points.Length = mesh.Vertices.Count Then
    For i As Integer = 0 To points.Length - 1
      mesh.Vertices.SetVertex(i, points(i))
    Next
    mesh.Normals.ComputeNormals()
  End If
  doc.Objects.AddMesh(mesh, objref.[Object]().Attributes)
  doc.Views.Redraw()
  Return Rhino.Commands.Result.Success
End Function

import Rhino
import scriptcontext
 
def UnrollSurface2():
    filter = Rhino.DocObjects.ObjectType.Brep | Rhino.DocObjects.ObjectType.Surface
    rc, objref = Rhino.Input.RhinoGet.GetOneObject("Select surface or brep to unroll", False, filter)
    if rc!=Rhino.Commands.Result.Success: return rc;
 
    unroll = Rhino.Geometry.Unroller(objref.Geometry())
    mesh = objref.Brep().Faces[0].GetMesh()
    if not mesh: return Rhino.Commands.Result.Cancel
 
    unroll.AddFollowingGeometry(mesh.Vertices.ToPoint3dArray())
    unroll.ExplodeOutput = False
    breps, curves, points, dots = unroll.PerformUnroll()
    # change the mesh vertices to the flattened form and add it to the document
    if points.Length==mesh.Vertices.Count:
        for i, point in enumerate(points): mesh.Vertices.SetVertex(i, point)
        mesh.Normals.ComputeNormals()
    scriptcontext.doc.Objects.AddMesh(mesh, objref.Object().Attributes)
    scriptcontext.doc.Views.Redraw()
    return Rhino.Commands.Result.Success
 
if __name__=="__main__":
    UnrollSurface2()