Determining chart values from 3D position

Oppi · Post by **Oppi** » Mon Oct 09, 2006 1:36 pm

Hello,

could you please help me with the following problems?

We are using custom x- and y-axes, all default axes are turned off and chart.view3d is set to true. I would like to display a tooltip at the mouse cursor position which shows the value at this position. In 2D this works perfectly using tcustomchartaxis.CalcPosPoint() but this does not work in 3D if the chart is rotated. Is there any other possibility to get the correct value?

The next thing I have noticed is a bug in tcolorlinetool in rotated charts. The anchor point (the line with which you drag the tool) is located somewhere at the side of the line. So if you try to grab the line nothing happens. Is this a known bug?

Best regards

Arnd

Narcís · Post by **Narcís** » Mon Oct 09, 2006 3:07 pm

Hi Arnd,

I think both problems come from the difficulty to convert 2D points to 3D points. This is a known problem, we've done some investigation and it is very difficult converting non-3D coordinates to 3D coordinates as, if I'm not wrong, GDI doesn't provide such methods nor does GDI+. So further investigation needs to be done on that aspect.

Oppi · Post by **Oppi** » Mon Oct 16, 2006 1:00 pm

Thank you for your reply. But is there any chance to get a method which calculates the correct 3d coordinates from mousex and mousey and a given z-value? Imagine a 3d chart which is rotated several degrees. Now I would like to start drawing a rectangle at z-position 0 where the user pressed the mouse button. Is this possible?

Thanks in advance

Arnd