Offset curve - C# Visual Studio - Rhino.Geometry.Curve[]' to 'Rhino.Geometry.Line

Replies to This Discussion

Permalink Reply by Daniel González Abalde on August 29, 2015 at 1:58pm

Hi Petras!

Why do you use the class polycurve instead of curve? The offset function returns an array of curves.

The code bellow collects the results in a list, was this what you wanted?

Brep glass = glassSrf;
Curve[] wireframe = glass.GetWireframe(0);
List<Curve> outline = new List<Curve>();

for (int i = 0; i < wireframe.Length; i++)
{

 outline.Add(wireframe[i]);
outline.AddRange(wireframe[i].Offset(Plane.WorldXY, -1, 0.1, 0));
}

return outline;

Permalink Reply by Petras Vestartas on August 29, 2015 at 2:26pm

Hi Daniel,

Thanks for a reply.

Your code in Visual studio does not make any error. But as long as I build the .dll file I get the error in Grasshopper showing that the output is List'1 but supported type is GH_Curve. (Look at attached image).

A part of code:

//Output

protected override void RegisterOutputParams(GH_Component.GH_OutputParamManager pManager)
        {

            pManager.AddCurveParameter("Glass", "G", "Glass surfaces", GH_ParamAccess.item);

        }

//Input

        protected override void SolveInstance(IGH_DataAccess DA)
        {
            // Input
            Brep glassSrf = new Brep();

            // When data cannot be extracted from a parameter, we should abort this method.
            if (!DA.GetData(0, ref glassSrf)) return;

            //Offset function
           List<Curve> glass = CreateGlass(glassSrf);

           //Output
           DA.SetData(0, glass);
        }

// Main function

        private List<Curve> CreateGlass(Brep glassSrf)
        {
            Brep glass = glassSrf;
            Curve[] wireframe = glass.GetWireframe(0);
            List<Curve> outlines = new List<Curve>();

            for (int i = 0; i < wireframe.Length; i++)
            {

                outlines.Add(wireframe[i]);
                outlines.AddRange(wireframe[i].Offset(Plane.WorldXY, -1, 0.1, 0));

            }

            return outlines;
        }

Attachments:

• error.jpg, 363 KB

Permalink Reply by Daniel González Abalde on August 29, 2015 at 2:59pm

I think it is because you set the output parameter as GH_ParamAccess.item, rather than GH_ParamAccess.List.

//Output

protected override void RegisterOutputParams(GH_Component.GH_OutputParamManager pManager)
        {

            pManager.AddCurveParameter("Glass", "G", "Glass surfaces", GH_ParamAccess.list);

        }

Permalink Reply by Petras Vestartas on August 29, 2015 at 4:03pm

Thanks it worked, but I had to joined wireframes curves before.

But now I do not get offset curves. Component output shows only outlines but no offset.

How correctly can I offset these boundary curves?

C#:

        private List<Curve> CreateGlass(Brep glassSrf)
        {
            Brep glass = glassSrf;
            Curve[] wireframe = glass.GetWireframe(0);
            Curve[] wireframeJoined = Curve.JoinCurves(wireframe);

            List<Curve> outlines = new List<Curve>();

            for (int i = 0; i < wireframe.Length; i++)
            {

                // component output is surface outline but not offset of the outline
                outlines.AddRange(wireframeJoined[i].Offset(Plane.WorldXY, -1, 0.1, 0));
            }

            return outlines;
        }