How to draw an elliptic cylinder?

[xsLiu]

The axis of an elliptic cylinder is a 3D curve, and its cross section at any position is an ellipse. The 3D curve and a series of cross-section ellipses are known. That is to say, we know the 3D coordinates of the curve and ellipses at any position. I have no idea to draw the elliptic cylinder. Would you like to give me an example? Thanks a lot.

[Yeray]

Hello,

I'm afraid there's no series or tool implemented in TeeChart doing this for you, but once you have the data, it should be possible to use a TSurfaceSeries or a TPoint3DSeries to draw it.

[xsLiu]

it should be possible to use a TSurfaceSeries or a TPoint3DSeries to draw it.

It is great and useful.
If it is required to draw a semitransparent surface, how to set Brush’s transparency? Or, is there any other way?

[Yeray]

Hello,

Transparency is applied with Blending:

Code: Select all

uses TeCanvas;
//...
var tmpBlend : TTeeBlend;
const transp=80;
begin
  //Prepare Pen and Brush

  if transp>0 then
     tmpBlend:=Chart1.Canvas.BeginBlending(TeeZeroRect,transp);

  //Draw polygon

  if transp>0 then
     Chart1.Canvas.EndBlending(tmpBlend);

[xsLiu]

It works fine.
How to make such a Series visible or not as required? i.e. use a CheckBox to make it visible or not.

[Yeray]

That depends on how are you drawing the polygons. If you are drawing them at a series' OnGetPointerStyle event as in the example I linked above, disabling the series should be enough to stop calling that event and thus your custom drawing code.