topic Re: why two CAD blockreference's shape is different in .NET Forum

why two CAD blockreference's shape is different

wokeyiyognshenme — Sun, 21 May 2023 14:47:14 GMT

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

but why do they have different shape, different basepoint ?

Re: why two CAD blockreference's shape is different

_gile — Sun, 21 May 2023 15:09:44 GMT

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).

Re: why two CAD blockreference's shape is different

wokeyiyognshenme — Mon, 22 May 2023 05:02:09 GMT

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 .

Re: why two CAD blockreference's shape is different

_gile — Mon, 22 May 2023 05:46:01 GMT

(view in My Videos)

Re: why two CAD blockreference's shape is different

wokeyiyognshenme — Tue, 23 May 2023 18:32:56 GMT

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

Re: why two CAD blockreference's shape is different

_gile — Wed, 24 May 2023 12:29:51 GMT

@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; }

回复： why two CAD blockreference's shape is different

wokeyiyognshenme — Mon, 29 May 2023 16:42:48 GMT

thankyou very much