展示

红色(1号色)是三维的,黄色(2号色)投影下来的,它是曲线,因为曲线是直线的父类.

命令

[CommandMethod("test_ty", CommandFlags.Modal | CommandFlags.Session | CommandFlags.Redraw)]
public static void JJ_testty()
{
    Database db = HostApplicationServices.WorkingDatabase;//当前的数据库
    Editor ed = Acap.DocumentManager.MdiActiveDocument.Editor;
    ed.WriteMessage("\n****{惊惊连盒}测试,投影三维图元到某个平面上");

    using (Acap.DocumentManager.MdiActiveDocument.LockDocument())//锁文档 CommandFlags.Session
    {
        db.Action(tr =>
        {
            //三维的线 
            var entity = new Line(Point3d.Origin, new Point3d(1, 1, 1));//var entity = EntityAdd.AddLineToEntity(Point3d.Origin, new Point3d(1, 1, 1));
            entity.ColorIndex = 1;
            var lineId = tr.AddEntityToMsPs(db, entity);

            var ids = new List<ObjectId>() { lineId };
            var cus = tr.Entitys2Plane(ids);
            foreach (var item in cus)
            {
                item.ColorIndex = 2;
                tr.AddEntityToMsPs(db, item);
            }
        });
    }
}

投影平面

/// <summary>
/// 投影平面
/// </summary> 
/// <param name="tr">事务</param>
/// <param name="ids">图元</param>
/// <param name="normal">投影方向</param>
/// <returns>投影到某个平面的图元</returns>
public static List<Curve> Entitys2Plane(this Transaction tr,
    IEnumerable<ObjectId> ids, Vector3d? normal = null)
{
    var ls = new List<Curve>();
    if (normal == null)
    {
        normal = Vector3d.ZAxis;//绕Z轴,也就是XY平面
    }
    var plane = new Plane(Point3d.Origin, normal.Value);
    foreach (var sobject in ids)
    {
        if (sobject.IsOk())
        {
            var curve = sobject.ToEntity(tr) as Curve;
            if (curve == null)
                continue;
            Curve pCurve = null;
            try
            {
                pCurve = curve.GetOrthoProjectedCurve(plane);
            }
            catch
            { }
            if (pCurve == null)
                continue; 
            ls.Add(pCurve);
        }
    }
    return ls;
}

/// <summary>
/// 将图形添加到数据库的当前空间中
/// </summary>
/// <param name="db">图形数据库</param>
/// <param name="ent">图形对象</param>
/// <returns>图形的ObjectId</returns>
public static ObjectId AddEntityToMsPs(this Transaction tr, Database db, Entity ent)
{
    ObjectId entId;
    //在位编辑的时候自动加到块内了,而不是模型空间,因为会把临时的数据拷贝回去块表记录上面
    //出现eLockViolation 是因 CommandFlags.Session | CommandFlags.Redraw 又没有锁文档
    var btRec = tr.GetObject(db.CurrentSpaceId, OpenMode.ForWrite) as BlockTableRecord;
    //加图元到块表记录,设定返回值
    entId = btRec.AppendEntity(ent);
    //更新数据
    tr.AddNewlyCreatedDBObject(ent, true);
    btRec.DowngradeOpen();
    btRec.Dispose();
    return entId;
}

(完)

cad.net 投影三维图元到某个平面上