如何对折线内的一组实体应用转换？

Question

我在 polyline entity 中有一组 entity 个对象，我想重新缩放。我创建了 Extents3d 对象来重新缩放对象以避免一个一个地重新缩放对象，但它不起作用：

Document document = Application.DocumentManager.MdiActiveDocument;
Database database = document.Database;


using(Transaction transaction = database.TransactionManager.StartTransaction())
{
   BlockTable blockTable = transaction.GetObject(database.BlockTableId, OpenMode.ForRead) as BlockTable;
   BlockTableRecord blockTableRecord = transaction.GetObject(blockTable[BlockTableRecord.ModelSpace], OpenMode.ForWrite) as BlockTableRecord;
   Polyline polyline = new Polyline();
   polyline.AddVertexAt(0, new Point2d(0.0, 0.0), 0, 0, 0);
   polyline.AddVertexAt(1, new Point2d(100.0, 100.0), 0, 0, 0);
   polyline.AddVertexAt(2, new Point2d(50.0, 500.0), 0, 0, 0);
   polyline.Closed = true;
   blockTableRecord.AppendEntity(polyline);
   transaction.AddNewlyCreatedDBObject(polyline, true);
   Extents3d boundary = polyline.GeometricExtents;
   boundary.TransformBy(Matrix3d.Scaling(1, Point3d.Origin));
   transaction.commit();
}

Answer 1

您应该将变换应用到折线本身，而不是边界（表示几何 space，而不是实体）。

关于在一个方向上缩放，问题是变换上的 Origin/Base 点：如果你设置原点，它将从 0,0,0 开始缩放，现在如果你想 'scale in all directions'，在多段线的中间使用一个点。检查下面。

另请注意，您的比例因子是 1，您需要一个不同的值：>1 将按比例放大，<1 将按比例缩小。

Document document = Application.DocumentManager.MdiActiveDocument;
Database database = document.Database;

using(Transaction transaction = database.TransactionManager.StartTransaction())
{
   BlockTable blockTable = transaction.GetObject(database.BlockTableId, OpenMode.ForRead) as BlockTable;
   BlockTableRecord blockTableRecord = transaction.GetObject(blockTable[BlockTableRecord.ModelSpace], OpenMode.ForWrite) as BlockTableRecord;
   Polyline polyline = new Polyline();
   polyline.AddVertexAt(0, new Point2d(0.0, 0.0), 0, 0, 0);
   polyline.AddVertexAt(1, new Point2d(100.0, 100.0), 0, 0, 0);
   polyline.AddVertexAt(2, new Point2d(50.0, 500.0), 0, 0, 0);
   polyline.Closed = true;
   blockTableRecord.AppendEntity(polyline);
   transaction.AddNewlyCreatedDBObject(polyline, true);
   Extents3d boundary = polyline.GeometricExtents;
   Point3d center = (new LineSegment3d(boundary.MinPoint, boundary.MaxPoint)).MidPoint;
   polyline.TransformBy(Matrix3d.Scaling(1, center));
   transaction.commit();
}

Answer 2

重新阅读你的问题，如果你想缩放由多边形区域分隔的实体，那么你首先需要 select 它们，缩放。你的代码绝对不是这样做的（我的建议也不是）。

到select，使用代码described here并复制如下：见特殊Editor.Select****方法。

在 select 之后，您就可以应用转换了。请注意 origin/base 点和比例因子。

[CommandMethod("SEL")]
public void MySelection()
{
    Document doc = Autodesk.AutoCAD
        .ApplicationServices.Application
        .DocumentManager.MdiActiveDocument;
    Editor ed = doc.Editor;

    Point3d p1 = new Point3d(10.0, 10.0, 0.0);
    Point3d p2 = new Point3d(10.0, 11.0, 0.0);
    Point3d p3 = new Point3d(11.0, 11.0, 0.0);
    Point3d p4 = new Point3d(11.0, 10.0, 0.0);

    Point3dCollection pntCol =
                      new Point3dCollection();
    pntCol.Add(p1);
    pntCol.Add(p2);
    pntCol.Add(p3);
    pntCol.Add(p4);

    int numOfEntsFound = 0;

    PromptSelectionResult pmtSelRes = null;

    TypedValue[] typedVal = new TypedValue[1];
    typedVal[0] = new TypedValue
                 ((int)DxfCode.Start, "Line");

    SelectionFilter selFilter =
              new SelectionFilter(typedVal);
    pmtSelRes = ed.SelectCrossingPolygon
                         (pntCol, selFilter);
    // May not find entities in the UCS area
    // between p1 and p3 if not PLAN view
    // pmtSelRes =
    //    ed.SelectCrossingWindow(p1, p3, selFilter);

    if (pmtSelRes.Status == PromptStatus.OK)
    {
        foreach (ObjectId objId in
            pmtSelRes.Value.GetObjectIds())
        {
            numOfEntsFound++;
        }
        ed.WriteMessage("Entities found " +
                    numOfEntsFound.ToString());
    }
    else
        ed.WriteMessage("\nDid not find entities");
}

如何对折线内的一组实体应用转换？

How to apply a transformation for a group of entities inside a polyline?

c#

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