I want to extract drawing extents from Civil3D dwg's using Design Automation.
If I use the code below:
static public Extents3d GetExtents(Database db) {
try {
//db.UpdateExt(true);
return new Extents3d(db.Extmin, db.Extmax);
} catch {
return new Extents3d();
}
}
Then I get the following result which is correct:
Min: [2538909.32, 330601.59, 0.00]
Max: [2540326.77, 331107.96, 0.00]
However, if I call db.UpdateExt(true) before or if I simply iterate all entities in model space with the code below, I get a min bound that is at origin:
static public Extents3d GetExtents(Database db) {
try {
var TxMng = db.TransactionManager;
using(var Tx = TxMng.StartTransaction()) {
var btr = Tx.GetObject(
db.CurrentSpaceId, OpenMode.ForRead)
as BlockTableRecord;
foreach(var id in btr) {
var entity = Tx.GetObject(id, OpenMode.ForRead)
as Entity;
extents.AddExtents(entity.GeometricExtents);
}
Tx.Commit();
}
return extents;
} catch {
return new Extents3d();
}
}
Outputs:
Min: [0.00, 0.00, 0.00]
Max: [2540326.77, 331107.96, 0.00]
Also opening the dwg in AutoCAD vanilla and doing a zoom extents will use this huge/invalid extents. So I think Civil knows that some entities should not be included when computing extents or is it something else?
I would like to be able to compute extents using the second approach (at least a modified working version of it) as it offers more granularity over what entities we want to consider if later on we have some more advanced requirements.
