public override void OnDraw(GeometryBuilder dc) { dc.Clear(); // Define the basic points for drawing Point3d pnt1 = _pnt1; Point3d pnt2 = new Point3d(_pnt2.X, pnt1.Y, 0); Point3d pnt3 = new Point3d(pnt2.X, pnt1.Y + 150, 0); Point3d pnt4 = new Point3d(pnt1.X, pnt3.Y, 0); // Set the color to ByObject value dc.Color = McDbEntity.ByObject; Vector3d hvec = new Vector3d(0, 0, _h); // Draw the upper and lower sides dc.DrawPolyline(new Point3d[] { pnt1, pnt2, pnt3, pnt4, _pnt1 }); dc.DrawPolyline(new Point3d[] { _pnt1.Add(hvec), pnt2.Add(hvec), pnt3.Add(hvec), pnt4.Add(hvec), pnt1.Add(hvec) }); // Draw the edges dc.DrawLine(pnt1, pnt1.Add(hvec)); dc.DrawLine(pnt2, pnt2.Add(hvec)); dc.DrawLine(pnt3, pnt3.Add(hvec)); dc.DrawLine(pnt4, pnt4.Add(hvec)); // Create contours for the front and rear sides and hatch them // In this demo, we hatch only two sides, you can tailor the others yourself List <Polyline3d> c1 = new List <Polyline3d>(); c1.Add(new Polyline3d( new List <Point3d>() { pnt1, pnt1.Add(hvec), pnt2.Add(hvec), pnt2, pnt1, })); dc.DrawGeometry(new Hatch(c1, "BRICK", 0, 20, false, HatchStyle.Normal, PatternType.PreDefined, 30), 1); List <Polyline3d> c2 = new List <Polyline3d>(); c2.Add(new Polyline3d( new List <Point3d>() { pnt4, pnt4.Add(hvec), pnt3.Add(hvec), pnt3, pnt4, })); dc.DrawGeometry(new Hatch(c2, "BRICK", 0, 20, false, HatchStyle.Normal, PatternType.PreDefined, 30), 1); }