[vtkusers] [vtk-developers] Overhaul of the rendering subsystem in VTK: Volume Rendering update

Mon Nov 3 11:24:58 EST 2014

On Mon, Nov 3, 2014 at 8:11 AM, Simon ESNEAULT <simon.esneault at gmail.com>
wrote:

> Hello,
>
> Thank you for letting us know the current changes in VTK volume rendering,
> that seems really exciting.
> In the source issue 31, I saw that your were asking to the community if
> there were any feature needed.
>

Nice, thanks for reading our article.

> One feature that we would really like to see is a way to have multiple
> opacity transfer functions together used with a label data map to mask the
> volume.
>

I believe I have seen a similar request earlier. I will add this feature to
our agenda.

> Right now it is possible to have multiple color TF, but not multiple
> opacity TF. Is this feature planned to be developed ? This would enable
> to have "almost transparent" structure in front of the camera and "opaque
> structure" in the back, even though the structure have the same scalar
> value. A visual example here
> <http://www.piemedicalimaging.com/product/3mensio-structural-heart/>, coming
> from the 3mensio software.
>

Thanks for the reference. I may contact you in case we make any progress
this direction.

Thanks,
Aashish

>
> Thanks,
> Simon
>
>
> 2014-10-22 20:27 GMT+02:00 Aashish Chaudhary <
> aashish.chaudhary at kitware.com>:
>
>> Friends,
>>
>> Some more good news on the rendering side of things. In the last few
>> days, we have worked on porting two more volume mappers to OpenGL2
>> (FixedPoint and Bunyk) and this noon we merged that code into VTK master.
>> This change should not affect the code that is using the OpenGL (and not
>> OpenGL2) backend. We will keep an eye on the dashboards and fix any issue
>> that we may find. Also, we have updated the vtkSmartVolumeMapper to deal
>> with the OpenGL and OpenGL2 backend.
>>
>> Please let us know if you have any questions or if you encounter any
>> issues in the current master related to this change.
>>
>> Thanks,
>>
>> On Thu, Oct 16, 2014 at 12:31 PM, Aashish Chaudhary <
>> aashish.chaudhary at kitware.com> wrote:
>>
>>> Friends,
>>>
>>> As referred earlier, we are continuously working on improving the volume
>>> rendering. As part of next set of delivery,  we are going to bring our
>>> first OpenGL2 volume mapper to the OpenGL2 backend.
>>> We have a branch that will get merged today and* it should only affect
>>> the dashboards and code base switched to OpenGL2 backend*. We will
>>> continue to improve the integration and will use and improve the
>>> existing OpenGL2 backend code as necessary.
>>>
>>> If you have any questions of concerns or if you find in any ways its
>>> affecting your regular builds that uses OpenGL(default, and not OpenGL2)
>>>  backend then let us know as soon as possible.
>>>
>>> Thanks,
>>>
>>>
>>> On Fri, Oct 10, 2014 at 9:53 AM, Aashish Chaudhary <
>>> aashish.chaudhary at kitware.com> wrote:
>>>
>>>> Friends,
>>>>
>>>>
>>>> As reported back in July, we are in the process of a major overhaul of
>>>> the rendering subsystem in VTK. The July article (
>>>> http://www.kitware.com/source/home/post/144) focused primarily on our
>>>> efforts to move to OpenGL 2.1+ to support faster polygonal rendering.  The
>>>> October Source will contain an article focused on our rewrite of the
>>>> vtkGPURayCastMapper class to provide a faster, more portable and more
>>>> easily extensible volume mapper for regular rectilinear grids.
>>>>
>>>>
>>>>
>>>> VTK has a long history of volume rendering, and unfortunately that
>>>> history is evident in the large selection of classes available to render
>>>> volumes. Each of these methods was state-of-the-art at the time, but given
>>>> VTK’s 20+ year history many of these methods are now quite obsolete. One
>>>> goal of this effort is to reduce the number of volume mappers to ideally
>>>> just two - one that supports accelerated rendering on graphics hardware and
>>>> another that works in parallel on the CPU. In addition, the
>>>> vtkSmartVolumeMapper would help application developers by automatically
>>>> choosing between these techniques based on system performance.
>>>>
>>>>
>>>>
>>>> In this first phase, we have created a replacement for
>>>> vtkGPURayCastMapper. Currently, this is available for testing from the VTK
>>>> git repository (in master branch, disabled by default). General
>>>> instructions on how to build VTK from the source is available at this URL:
>>>> http://www.vtk.org/Wiki/VTK/Git*. *In order to build the new mapper,
>>>> enable the Module_vtkRenderingVolumeOpenGLNew module in cmake (via -D
>>>> *Module_vtkRenderingVolumeOpenGL=ON*), in ccmake or cmake-gui. Once
>>>> built, it can be used via vtkSmartVolumeMapper or used directly. Once
>>>> sufficient testing by the community has been performed, this class will
>>>> replace the old vtkGPURayCastMapper.  In addition, we are adding this new
>>>> mapper to the OpenGL2 module.  Availability of the new mapper with OpenGL2
>>>> module will improve the management of textures in the mapper and eventually
>>>> benefitting both forms of rendering (geometry and volume) by sharing common
>>>> code between them.
>>>>
>>>>
>>>> Please contact us if you have any questions or encounter any issues.
>>>>
>>>>
>>>> Thanks,
>>>>
>>>> --
>>>>
>>>>
>>>>
>>>> *| Aashish Chaudhary | Technical Leader         | Kitware Inc.
>>>>   *
>>>> *| http://www.kitware.com/company/team/chaudhary.html
>>>> <http://www.kitware.com/company/team/chaudhary.html>*
>>>>
>>>
>>>
>>>
>>> --
>>>
>>>
>>>
>>> *| Aashish Chaudhary | Technical Leader         | Kitware Inc.
>>>   *
>>> *| http://www.kitware.com/company/team/chaudhary.html
>>> <http://www.kitware.com/company/team/chaudhary.html>*
>>>
>>
>>
>>
>> --
>>
>>
>>
>> *| Aashish Chaudhary | Technical Leader         | Kitware Inc.
>> *
>> *| http://www.kitware.com/company/team/chaudhary.html
>> <http://www.kitware.com/company/team/chaudhary.html>*
>>
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>
>
> --
> ------------------------------------------------------------------
> Simon Esneault
> 13 rue Vasselot
> 35000 Rennes, France
> Tel : 06 64 61 30 94
> Mail : simon.esneault at gmail.com
> ------------------------------------------------------------------
>

-- 

*| Aashish Chaudhary | Technical Leader         | Kitware Inc.            *
*| http://www.kitware.com/company/team/chaudhary.html
<http://www.kitware.com/company/team/chaudhary.html>*
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