【Revit API】梁的凈高分析

原理就是，先從梁的LocationCurve上取點，然後向板的上錶面投影。如果有投影點，再從投影點（板上）向梁的底面投影，這時候如果有投影點的話就能得到距離了。

運用該分析的第一條件是梁是在板的上方，勿忘哈！

var beamBottomFaces = FaceUtils.GetBottomFaces(beam); //這個方法是自己封裝的
if (null != beamBottomFaces && beamBottomFaces.Any())
{
    var beamLocationCurve = beam.Location as LocationCurve;
    var beamCurve = beamLocationCurve.Curve;
    if (beamCurve != null)
    {
         if (beamCurve is Line)
         {
              beamCurve = GetExtLocationCurve(beamCurve); //如果LocationCurve是Line，最好做個延伸演算法來延長，不然有些梁因為扣減的話，locationCurve容易缺少一部分
         }
         var beamPoints = GetPoints(beamCurve, pointRange); //pointRange是取點間隔
         if (beamPoints != null && beamPoints.Any())
         {
              var floorDataList = GetBeamFloorsPairCore(beamBottomFaces, beamPoints, floors); //floors為建築板                               
         }
    }
}

LocationCurve的延伸：

private Curve GetExtLocationCurve(Curve curve)
{
     XYZ dir0 = XYZ.Zero;
     XYZ dir1 = XYZ.Zero;
     if (curve is Line)
     {
          dir0 = (curve as Line).Direction.Negate();
          dir1 = (curve as Line).Direction;
     }
      Curve extCurve = Line.CreateBound(curve.GetEndPoint(0) + 1E3 * dir0, curve.GetEndPoint(1) + 1E3 * dir1);
      return extCurve;
}

在Curve上按PointRange選取點位：

private List<XYZ> GetPoints(Curve curve, double pointRange)
{
       var points = new List<XYZ>();
       var beamLength = curve.Length;
       var pointsNumber = beamLength % pointRange == 0 ? ((beamLength / pointRange) - 1) : Math.Floor((beamLength / pointRange));

       for(var i = 1; i <= pointsNumber; i++)
       {
          var point = curve.Evaluate(pointRange * i, false);
          points.Add(point);
       }
       return points;
}

 獲取距離：

private List<KeyValuePair<Element, List<KeyValuePair<XYZ, double>>>> GetBeamFloorsPairCore(List<PlanarFace> beamBottomFaces, IEnumerable<XYZ> beamPoints, List<Element> floors)
{
      var floorDataList = new List<KeyValuePair<Element, List<KeyValuePair<XYZ, double>>>>();
      //尋找每一塊結構梁下的板
      foreach (var floor in constructionFloors)
      {
         //獲取該板的最上點坐標
         var floorTopFaces = FaceUtils.GetTopFaces(floor);
         if (null != floorTopFaces && floorTopFaces.Any())
         {
              var defaultFloorOriginZ = floorTopFaces.FirstOrDefault().Origin.Z;
              foreach (var tf in floorTopFaces)
              {
                   var originZ = tf.Origin.Z;
                   if (defaultFloorOriginZ <= originZ)
                   {
                       defaultFloorOriginZ = originZ;
                   }
              }

                   
              var defaultBeamOriginZ = beamBottomFaces.FirstOrDefault().Origin.Z;
              foreach (var bf in beamBottomFaces)
              {
                   var originZ = bf.Origin.Z;
                   if (defaultBeamOriginZ >= originZ)
                   {
                       defaultBeamOriginZ = originZ;
                   }
              }
              //板在梁下麵
              var isLower = defaultFloorOriginZ < defaultBeamOriginZ;

              if (isLower)
              {
                   var datalist = new List<KeyValuePair<XYZ, double>>();
                   //梁上一點能投影到板上
                   foreach (var point in beamPoints)
                   {
                       foreach (var tf in floorTopFaces)
                       {
                           var isProject = tf.Project(point);
                           if (null != isProject)
                           {
                               //投影到板上點的坐標
                               var projectPoint = isProject.XYZPoint;

                               //投影點到梁上點的距離
                               foreach (var bf in beamBottomFaces)
                               {
                                   var bp = bf.Project(projectPoint);
                                   if (null != bp)
                                   {
                                       var distance = bp.Distance;
                                       distance = UnitUtils.ConvertFromInternalUnits(distance, DisplayUnitType.DUT_MILLIMETERS);
                                       distance = Math.Floor(distance);

                                       var pointAndDistance = new KeyValuePair<XYZ, double>(projectPoint, distance);
                                       datalist.Add(pointAndDistance);
                                       break;
                                    }
                                }
                            }
                        }                            
                    }

                    if (datalist != null && datalist.Any())
                    {
                       var floorAndData = new KeyValuePair<Element, List<KeyValuePair<XYZ, double>>>(floor, datalist);
                       floorDataList.Add(floorAndData);
                    }
                }
           }
     }
     return floorDataList;
}