Steema Central

Posted: **Wed Sep 13, 2023 1:32 pm**

I am visualyzing subsurface borehole data (X,Y,Z) using a TPoint3DSeries. That works fine. However, when I want to display marks with the series that show some text I can only post them above the points. There doesn't seem to be a default option to draw them left or right of a point like there is in Excel (2D) charts.

As most of the boreholes are near vertical this means that the majority of the labels are overlapping and are plotted on top of previous points or labels. Is there a way to solve this?

I have scrutinized answers in the VCL forum but I couldn't find anything that seems to address my particular (3D) problem. Is there a menu setting, or a property setting that I have overlooked? Or is there a way to achieve this in code? If the latter applies, can you point me to an example?

Posted: **Thu Sep 14, 2023 8:20 am**

Hello Jan,

I'm not sure how are you exactly drawing your TPoint3DSeries but here it is an example showing a simple one with all the points with the same XValue.
Here what I'm getting:

: VerticalPoint3D_Marks.png (17.96 KiB) Viewed 15276 times

Code: Select all

uses TeEngine, Chart,  TeePoin3;

var Chart1: TChart;

procedure TForm1.FormCreate(Sender: TObject);
var i: Integer;
begin
  Chart1:=TChart.Create(Self);

  with Chart1 do
  begin
    Parent:=Self;
    Align:=alClient;
    Color:=clWhite;
    Gradient.Visible:=False;
    Walls.Back.Color:=clWhite;
    Walls.Back.Gradient.Visible:=False;
    Legend.Hide;
    //View3D:=False;
    Chart3DPercent:=100;
    View3DOptions.Orthogonal:=False;
    View3DOptions.Zoom:=80;
    View3DOptions.Rotation:=360;
    View3DOptions.Elevation:=360;
  end;

  with TPoint3DSeries(Chart1.AddSeries(TPoint3DSeries)) do
  begin
    Marks.Show;
    Marks.Automatic.Move:=False;
    Marks.ArrowLength:=10;
    LinePen.Hide;

    for i:=0 to 19 do
      AddXYZ(0, i, random*3);

    Chart1.Draw;
    OnGetMarkText:=SeriesGetMarkText;
  end;
end;

Procedure TForm1.SeriesGetMarkText(Sender:TChartSeries; ValueIndex:Integer; var MarkText:String);
var
  APosition: TSeriesMarkPosition;
  XPos,YPos: Integer;
const XOff=0;
const YOff=0;
begin
  inherited;

  with Sender do
  begin
    APosition:=Marks.Positions[ValueIndex];

    if APosition=nil then
    begin
      APosition:=TSeriesMarkPosition.Create;
      APosition.Custom:=True;
    end;

    XPos:=CalcXPos(ValueIndex);
    YPos:=CalcYPos(ValueIndex);
    APosition.LeftTop.X:=XPos+Marks.ArrowLength+Round(XOff);
    APosition.LeftTop.Y:=YPos-(APosition.Height div 2)+Round(YOff);
    APosition.ArrowFrom:=Point(XPos,YPos);
    APosition.ArrowTo:=Point(APosition.LeftTop.X+(APosition.Width div 2),APosition.LeftTop.Y+(APosition.Height div 2));
    Marks.Positions[ValueIndex]:=APosition;
  end;
end;

Steema Central

Posting marks left or right for a TPoint3DSeries

Posting marks left or right for a TPoint3DSeries

Re: Posting marks left or right for a TPoint3DSeries