[vtk-developers] vtkClipPlanesPainter

[John Biddiscombe]

Utkarsh
> I wonder what's the problem with calling glDisable() at the end of the 
> vtkOpenGLClipPlanesPainter::RenderInternal() call. Notice that before 
> calling glDisable(), this class allows the superclass to render. The 
> superclass conveys the render calls to all it's delegates (which will 
> include all the painters that render the geometry etc etc.). Hence 
> they would have "rendered" before glDisable() gets called.
OK. I obviously misunderstood the way it was supposed to work. I just 
wanted to call glEnable(...) before rendering and glDisable(...) 
afterwards with the relevant setup of planes handled for me. It seems I 
can't use vtkClipPlanesPainter without creating a whole load of other 
glue logic around it.

FYI. I just wanted to render into a FrameBufferObject with the clip 
planes set specially for an effect, then use the FrameBuffer as the 
input to another process. I had hoped to make use of the Painters to 
make life easier
>
> Here a link to the original design of the painter:
> http://www.vtk.org/Wiki/images/5/5f/VtkPainter_Overview.pdf

I'll read this thoroughly. I note it dates back to 2004! (I wonder if 
the plan has been adhered to)

JB
>
> Utkarsh.
>
>
> John Biddiscombe wrote:
>> Dear Anyone,
>>
>> I notice that vtkClipPlanesPainter (specifically OpenGLPainter) calls 
>> glEnagle(...) at the start of Render and glDisable(...) at the end of 
>> the render. I presume this is because nobody actually uses this 
>> painter right now and so it hasn't been noticed.
>>
>> 2 questions.
>> 1) I've added a PostRender method to the clipplanes base class so 
>> that PostRender can be called after the main mapper has terminated. 
>> Any objection to this (by which I mean, does someone have a plan 
>> already which conflicts with this?)
>> 2) Is there any documentation on the painter classes I am mostly 
>> still using customized mappers for my special <cough> stuff, but 
>> would like to explore the painters a bit more.
>>
>> thanks
>>
>> JB
>>
>


-- 
John Biddiscombe,                            email:biddisco @ cscs.ch
http://www.cscs.ch/about/BJohn.php
CSCS, Swiss National Supercomputing Centre  | Tel:  +41 (91) 610.82.07
Via Cantonale, 6928 Manno, Switzerland      | Fax:  +41 (91) 610.82.82