[vtk-developers] Line picking

[Will Schroeder]

Pat-

For now use vtkCellPicker (I'll attached the modified C++ file) it works
much better. I believe what's going on is the rendering pass made during the
picking process is not consistent with the display rendering pass, hence the
picking is working badly. I'm going to have to dive deeper into this which
my brain is resisting this being early Sunday morning (and I am in Bar
Harbor watching the sunrise :-))

Note that David Gobbi is reworking vtkCellPicker and if he hasn't checked it
in yet, will do so shortly. By using a locator with the new vtkCellPicker
you will get great performance. plus more information than vtkPropPicker can
give you.

Let me know if you need more help and I'll give you a call, in the mean time
I'll back burner the vtkPropPicker for lines.

Will

On Sat, Jan 23, 2010 at 1:22 PM, pat marion <pat.marion at kitware.com> wrote:

> I hacked one of the vtk examples to demonstrate the bug.  Attached and
> copied below.  With the bug, it will only print "Pick success" when the x
> coordinate of the mouse press is 150.
>

...stuff removed....


>
> On Fri, Jan 22, 2010 at 1:18 PM, pat marion <pat.marion at kitware.com>wrote:
>
>> Using vtkPropPicker::PickProp it is difficult to pick lines (using a
>> vtkLineSource with a vtkPolyDataMapper for example).  Even if I set the line
>> width to 10 pixels, the pick is only successful if I click exactly in the
>> center of the 10 pixel band, as if the hardware picker was not respecting
>> the 10 pixel width.  Can someone that is familiar with this part of vtk
>> verify the bug, or point me in the right direction?
>>
>> Pat
>>
>
>
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