why two CAD blockreference's shape is different

[wokeyiyognshenme]

in the dwg,two blockreference  has same name ,same rotation.

but why do they have different shape, different basepoint ?

[_gile]

Hi,

The block on the left does not lies on the XY plane, its normal is: 0.0168726, 0.0, 0.999858 (slightly rotated on Y axis).

The Rotation property of a block reference is measuered about the X axis of the Object Corrdinate System (OCS).

[wokeyiyognshenme]

 How to reproduce this problem。

do you mean

1。first,  set a ocs, forexamble, its Zaxis is (a,b,c).

2。second ,insert a blockreference in the OCS ?

I DON'T know how to draw. could you give a Operation video ---Screen recording。

thank you .

[wokeyiyognshenme]

great!!!

thank your very much.

another problem：

the left blockreference is not drawed in wcs.

how to get the four point(X,Y,z) of the rectangle in wcs

[_gile · Accepted solution]

---

@wokeyiyognshenme  a écrit :

the left blockreference is not drawed in wcs.

how to get the four point(X,Y,z) of the rectangle in wcs

---

You can either get the coordinates of the polyline by exploding the block reference or from the block definition.

        public static Point3dCollection GetPolylineCoordinates(Polyline pline)
        {
            var points = new Point3dCollection();
            for (int i = 0; i < pline.NumberOfVertices; i++)
            {
                points.Add(pline.GetPoint3dAt(i));
            }
            return points;
        }

        private static Point3dCollection GetPolylineCoordinatesByExploding(BlockReference br)
        {
            var entitySet = new DBObjectCollection();
            br.Explode(entitySet);
            var points = new Point3dCollection();
            foreach (Entity entity in entitySet)
            {
                if (entity is Polyline pline)
                {
                    points = GetPolylineCoordinates(pline); 
                }
                entity.Dispose();
            }
            return points;
        }

        private static Point3dCollection GetPolylineCoordinatesFromBlockDefinition(BlockReference br)
        {
            var btr = (BlockTableRecord)br.BlockTableRecord.GetObject(OpenMode.ForRead);
            var points = new Point3dCollection();
            foreach (ObjectId id in btr)
            {
                if (id.ObjectClass.Name == "AcDbPolyline")
                {
                    var pline = (Polyline)id.GetObject(OpenMode.ForRead);
                    foreach (Point3d point in GetPolylineCoordinates(pline))
                    {
                        points.Add(point.TransformBy(br.BlockTransform));
                    }
                }
            }
            return points;
        }

[wokeyiyognshenme]

thankyou very much