makerhinocontours

          
using System;
using Rhino;
using Rhino.DocObjects;
using Rhino.Geometry;
using Rhino.Input;
using Rhino.Input.Custom;
using Rhino.Commands;

namespace examples_cs
{
  public class ContourCommand : Command
  {
    public override string EnglishName { get { return "csContour"; } }

    protected override Result RunCommand(RhinoDoc doc, RunMode mode)
    {
      var filter = ObjectType.Surface | ObjectType.PolysrfFilter | ObjectType.Mesh;
      ObjRef[] obj_refs;
      var rc = RhinoGet.GetMultipleObjects("Select objects to contour", false, filter, out obj_refs);
      if (rc != Result.Success)
        return rc;

      var gp = new GetPoint();
      gp.SetCommandPrompt("Contour plane base point");
      gp.Get();
      if (gp.CommandResult() != Result.Success)
        return gp.CommandResult();
      var base_point = gp.Point();

      gp.DrawLineFromPoint(base_point, true);
      gp.SetCommandPrompt("Direction perpendicular to contour planes");
      gp.Get();
      if (gp.CommandResult() != Result.Success)
        return gp.CommandResult();
      var end_point = gp.Point();

      if (base_point.DistanceTo(end_point) < RhinoMath.ZeroTolerance)
        return Result.Nothing;

      double distance = 1.0;
      rc = RhinoGet.GetNumber("Distance between contours", false, ref distance);
      if (rc != Result.Success)
        return rc;

      var interval = Math.Abs(distance);

      Curve[] curves = null;
      foreach (var obj_ref in obj_refs)
      {
        var geometry = obj_ref.Geometry();
        if (geometry == null)
          return Result.Failure;

        if (geometry is Brep)
        {
          curves = Brep.CreateContourCurves(geometry as Brep, base_point, end_point, interval);
        }
        else
        {
          curves = Mesh.CreateContourCurves(geometry as Mesh, base_point, end_point, interval);
        }

        foreach (var curve in curves)
        {
          var curve_object_id = doc.Objects.AddCurve(curve);
          doc.Objects.Select(curve_object_id);
        }
      }

      if (curves != null)
        doc.Views.Redraw();
      return Result.Success;
    }
  }
}