SurfaceFrameAt Method

public bool FrameAt(
	double u,
	double v,
	out Plane frame
)

Public Function FrameAt ( 
	u As Double,
	v As Double,
	<OutAttribute> ByRef frame As Plane
) As Boolean

partial class Examples
{
  public static Rhino.Commands.Result OrientOnSrf(Rhino.RhinoDoc doc)
  {
    // Select objects to orient
    Rhino.Input.Custom.GetObject go = new Rhino.Input.Custom.GetObject();
    go.SetCommandPrompt("Select objects to orient");
    go.SubObjectSelect = false;
    go.GroupSelect = true;
    go.GetMultiple(1, 0);
    if (go.CommandResult() != Rhino.Commands.Result.Success)
      return go.CommandResult();

    // Point to orient from
    Rhino.Input.Custom.GetPoint gp = new Rhino.Input.Custom.GetPoint();
    gp.SetCommandPrompt("Point to orient from");
    gp.Get();
    if (gp.CommandResult() != Rhino.Commands.Result.Success)
      return gp.CommandResult();

    // Define source plane
    Rhino.Display.RhinoView view = gp.View();
    if (view == null)
    {
      view = doc.Views.ActiveView;
      if (view == null)
        return Rhino.Commands.Result.Failure;
    }
    Rhino.Geometry.Plane source_plane = view.ActiveViewport.ConstructionPlane();
    source_plane.Origin = gp.Point();

    // Surface to orient on
    Rhino.Input.Custom.GetObject gs = new Rhino.Input.Custom.GetObject();
    gs.SetCommandPrompt("Surface to orient on");
    gs.GeometryFilter = Rhino.DocObjects.ObjectType.Surface;
    gs.SubObjectSelect = true;
    gs.DeselectAllBeforePostSelect = false;
    gs.OneByOnePostSelect = true;
    gs.Get();
    if (gs.CommandResult() != Rhino.Commands.Result.Success)
      return gs.CommandResult();

    Rhino.DocObjects.ObjRef objref = gs.Object(0);
    // get selected surface object
    Rhino.DocObjects.RhinoObject obj = objref.Object();
    if (obj == null)
      return Rhino.Commands.Result.Failure;
    // get selected surface (face)
    Rhino.Geometry.Surface surface = objref.Surface();
    if (surface == null)
      return Rhino.Commands.Result.Failure;
    // Unselect surface
    obj.Select(false);

    // Point on surface to orient to
    gp.SetCommandPrompt("Point on surface to orient to");
    gp.Constrain(surface, false);
    gp.Get();
    if (gp.CommandResult() != Rhino.Commands.Result.Success)
      return gp.CommandResult();

    // Do transformation
    Rhino.Commands.Result rc = Rhino.Commands.Result.Failure;
    double u, v;
    if (surface.ClosestPoint(gp.Point(), out u, out v))
    {
      Rhino.Geometry.Plane target_plane;
      if (surface.FrameAt(u, v, out target_plane))
      {
        // Build transformation
        Rhino.Geometry.Transform xform = Rhino.Geometry.Transform.PlaneToPlane(source_plane, target_plane);

        // Do the transformation. In this example, we will copy the original objects
        const bool delete_original = false;
        for (int i = 0; i < go.ObjectCount; i++)
          doc.Objects.Transform(go.Object(i), xform, delete_original);

        doc.Views.Redraw();
        rc = Rhino.Commands.Result.Success;
      }
    }
    return rc;
  }
}

Partial Class Examples
  Public Shared Function OrientOnSrf(ByVal doc As Rhino.RhinoDoc) As Rhino.Commands.Result
    ' Select objects to orient
    Dim go As New Rhino.Input.Custom.GetObject()
    go.SetCommandPrompt("Select objects to orient")
    go.SubObjectSelect = False
    go.GroupSelect = True
    go.GetMultiple(1, 0)
    If go.CommandResult() <> Rhino.Commands.Result.Success Then
      Return go.CommandResult()
    End If

    ' Point to orient from
    Dim gp As New Rhino.Input.Custom.GetPoint()
    gp.SetCommandPrompt("Point to orient from")
    gp.Get()
    If gp.CommandResult() <> Rhino.Commands.Result.Success Then
      Return gp.CommandResult()
    End If

    ' Define source plane
    Dim view As Rhino.Display.RhinoView = gp.View()
    If view Is Nothing Then
      view = doc.Views.ActiveView
      If view Is Nothing Then
        Return Rhino.Commands.Result.Failure
      End If
    End If
    Dim source_plane As Rhino.Geometry.Plane = view.ActiveViewport.ConstructionPlane()
    source_plane.Origin = gp.Point()

    ' Surface to orient on
    Dim gs As New Rhino.Input.Custom.GetObject()
    gs.SetCommandPrompt("Surface to orient on")
    gs.GeometryFilter = Rhino.DocObjects.ObjectType.Surface
    gs.SubObjectSelect = True
    gs.DeselectAllBeforePostSelect = False
    gs.OneByOnePostSelect = True
    gs.Get()
    If gs.CommandResult() <> Rhino.Commands.Result.Success Then
      Return gs.CommandResult()
    End If

    Dim objref As Rhino.DocObjects.ObjRef = gs.[Object](0)
    ' get selected surface object
    Dim obj As Rhino.DocObjects.RhinoObject = objref.[Object]()
    If obj Is Nothing Then
      Return Rhino.Commands.Result.Failure
    End If
    ' get selected surface (face)
    Dim surface As Rhino.Geometry.Surface = objref.Surface()
    If surface Is Nothing Then
      Return Rhino.Commands.Result.Failure
    End If
    ' Unselect surface
    obj.[Select](False)

    ' Point on surface to orient to
    gp.SetCommandPrompt("Point on surface to orient to")
    gp.Constrain(surface, False)
    gp.Get()
    If gp.CommandResult() <> Rhino.Commands.Result.Success Then
      Return gp.CommandResult()
    End If

    ' Do transformation
    Dim rc As Rhino.Commands.Result = Rhino.Commands.Result.Failure
    Dim u As Double, v As Double
    If surface.ClosestPoint(gp.Point(), u, v) Then
      Dim target_plane As Rhino.Geometry.Plane
      If surface.FrameAt(u, v, target_plane) Then
        ' Build transformation
        Dim xform As Rhino.Geometry.Transform = Rhino.Geometry.Transform.PlaneToPlane(source_plane, target_plane)

        ' Do the transformation. In this example, we will copy the original objects
        Const delete_original As Boolean = False
        For i As Integer = 0 To go.ObjectCount - 1
          doc.Objects.Transform(go.[Object](i), xform, delete_original)
        Next

        doc.Views.Redraw()
        rc = Rhino.Commands.Result.Success
      End If
    End If
    Return rc
  End Function
End Class

import Rhino
import scriptcontext
import System.Guid

def OrientOnSrf():
    # Select objects to orient
    go = Rhino.Input.Custom.GetObject()
    go.SetCommandPrompt("Select objects to orient")
    go.SubObjectSelect = False
    go.GroupSelect = True
    go.GetMultiple(1, 0)
    if go.CommandResult()!=Rhino.Commands.Result.Success:
        return go.CommandResult()

    # Point to orient from
    gp = Rhino.Input.Custom.GetPoint()
    gp.SetCommandPrompt("Point to orient from")
    gp.Get()
    if gp.CommandResult()!=Rhino.Commands.Result.Success:
        return gp.CommandResult()

    # Define source plane
    view = gp.View()
    if not view:
        view = doc.Views.ActiveView
        if not view: return Rhino.Commands.Result.Failure

    source_plane = view.ActiveViewport.ConstructionPlane()
    source_plane.Origin = gp.Point()

    # Surface to orient on
    gs = Rhino.Input.Custom.GetObject()
    gs.SetCommandPrompt("Surface to orient on")
    gs.GeometryFilter = Rhino.DocObjects.ObjectType.Surface
    gs.SubObjectSelect = True
    gs.DeselectAllBeforePostSelect = False
    gs.OneByOnePostSelect = True
    gs.Get()
    if gs.CommandResult()!=Rhino.Commands.Result.Success:
        return gs.CommandResult()

    objref = gs.Object(0)
    # get selected surface object
    obj = objref.Object()
    if not obj: return Rhino.Commands.Result.Failure
    # get selected surface (face)
    surface = objref.Surface()
    if not surface: return Rhino.Commands.Result.Failure
    # Unselect surface
    obj.Select(False)

    # Point on surface to orient to
    gp.SetCommandPrompt("Point on surface to orient to")
    gp.Constrain(surface, False)
    gp.Get()
    if gp.CommandResult()!=Rhino.Commands.Result.Success:
        return gp.CommandResult()

    # Do transformation
    rc = Rhino.Commands.Result.Failure
    getrc, u, v = surface.ClosestPoint(gp.Point())
    if getrc:
        getrc, target_plane = surface.FrameAt(u,v)
        if getrc:
            # Build transformation
            xform = Rhino.Geometry.Transform.PlaneToPlane(source_plane, target_plane)
            # Do the transformation. In this example, we will copy the original objects
            delete_original = False
            for i in range(go.ObjectCount):
                rhobj = go.Object(i)
                scriptcontext.doc.Objects.Transform(rhobj, xform, delete_original)
            scriptcontext.doc.Views.Redraw()
            rc = Rhino.Commands.Result.Success
    return rc


if __name__=="__main__":
    OrientOnSrf()