Hi, I’ve got a problem when I tried to intersect two surfaces.
I attached some pictures as below. #1: intersection surfaces #2, #3: unexpected results #4: expected result
#2. Intersection result by using Solid → Intersection or Rhno.Geometry.Intersect.SurfaceSurfce of RhinoCommon (Selection of two surfaces and an intersection curve)
I’ve tried to get an intersection curve of two surfaces by using Solid->Intersection in Rhino App and Rhno.Geometry.Intersect.SurfaceSurfce of RhinoCommon, but results were not what I expected. (See #2 and #3)
By the way, I can get the good result as depicted #4 if I use “IntersectTwoSets” command in Rhino App.
Eventually, I am finding out the RhinoCommon function that works the same way with “IntersectTwoSets”.
I will very appreciate if somebody help me.
This Python script seems to work on your two surfaces:
import Rhino
import scriptcontext as sc
def test_intersect_breps():
go = Rhino.Input.Custom.GetObject()
go.SetCommandPrompt('Select two surfaces to intersect')
go.GeometryFilter = Rhino.DocObjects.ObjectType.Surface
go.SubObjectSelect = False
go.GetMultiple(2, 2)
if go.CommandResult() != Rhino.Commands.Result.Success:
return
brep0 = go.Object(0).Brep()
brep1 = go.Object(1).Brep()
if not brep0 or not brep1:
return
rc, curves, points = Rhino.Geometry.Intersect.Intersection.BrepBrep(brep0, brep1, sc.doc.ModelAbsoluteTolerance)
if rc:
for c in curves:
sc.doc.Objects.AddCurve(c)
for p in points:
sc.doc.Objects.AddPoint(p)
sc.doc.Views.Redraw()
if __name__ == "__main__":
test_intersect_breps()
Thank you for your kind reply.
It seems to be my mistake when I get Brep from RhinoObject.
The function of Rhino.Geometry.Intersect.Intersection.BrepBrep can’t generate intersectionCurves when I use Brep instance returned from ObjRef.Brep().
It works If I use go.Object().Brep().
I remerber that I didn’t have any problems when I used ObjRef.Brep() or ObjRef.Surface()/Curve(). Please let me know the difference betwwen RhinoObject.Brep() and ObjRef.Brep().
Best regards,
SG
My test code is as below.
public class IntersectionTest : Command
{
public IntersectionTest()
{
Instance = this;
}
///<summary>The only instance of the MyCommand command.</summary>
public static IntersectionTest Instance { get; private set; }
public override string EnglishName => "IntersectionTest";
protected override Result RunCommand(RhinoDoc doc, RunMode mode)
{
// TODO: complete command.
Rhino.Input.Custom.GetObject go = new Rhino.Input.Custom.GetObject();
go.SetCommandPrompt("select surfaces to intersect");
go.GeometryFilter = Rhino.DocObjects.ObjectType.Surface;
go.SubObjectSelect = false;
go.EnablePressEnterWhenDonePrompt(true);
go.GetMultiple(2,2);
if (go.CommandResult() != Rhino.Commands.Result.Success)
return go.CommandResult();
Rhino.DocObjects.ObjRef objRef1 = go.Object(0);
Rhino.DocObjects.ObjRef objRef2 = go.Object(1);
Brep brep1 = go.Object(0).Brep(); // objRef2.Brep();
Brep brep2 = go.Object(1).Brep(); // objRef2.Brep();
double tolerance = doc.ModelAbsoluteTolerance;
Curve[] intersectionCurves;
Point3d[] intersectionPoints;
if(!Rhino.Geometry.Intersect.Intersection.BrepBrep(
brep1,
brep2,
tolerance,
out intersectionCurves,
out intersectionPoints))
{
return Result.Failure;
}
foreach(Curve curve in intersectionCurves)
{
doc.Objects.Add(curve);
}
doc.Views.Redraw();
return Result.Success;
}
}
A RhinoObject represents a geometric object in the document. A RhinoObject consists of two pieces: something that inherits from GeometryBase, and ObjectAttributes.
An ObjRef represents a reference to a RhinoObject. These are usually created by an object picking operation, such as RhinoGet.GetOneObject, RhinoGet.GetMultipleObjects, and GetObject. There are other ways to construct these too. In addition to containing a reference to a RhinoObject, an ObjRef also provide details on how or where the object was picked. It can also create proxy objects when needed (a Brep when you pick a ExtrusionObject, for example).
