[vtkusers] vtkExtractVOI and volume raycast

[Jean M. Favre]

Richard Layman wrote:

>>> I made some changes to the VolumeRendering/SimpleRayCast example.
>>> Basically what I wanted to do is to dynamically select a subvolume
>>> within a given data volume to render. I use vtkExtractVOI to get the
>>> subvolume I want and feed this to the rendering pipeline. An outline
>>> is added for reference.
>>>

I can suggest an alternative which works very well for me. I do not use
a vtkExtractVOI, but rather tell directly the mappers to do cropping. In
my application, I use three different mappers (vtkVolumeTextureMapper2D,
 vtkVolumeTextureMapper3D, and vtkFixedPointVolumeRayCastMapper) which
all support the following options:

    vm2 SetCroppingRegionFlagsToSubVolume
    vm2 SetCroppingRegionPlanes $xminslice $xmaxslice $yminslice
$ymaxslice   $zminslice $zmaxslice

the last call takes the same 6 plane indices which you are using with
your ExtractVOI.


-- 
Dr. Jean M. Favre,                            email:favre @ cscs.ch
http://www.cscs.ch/about/Favre.php
CSCS, Swiss National Supercomputing Centre  | Tel:  +41 (91) 610.82.40
Via Cantonale, 6928 Manno, Switzerland      | Fax:  +41 (91) 610.82.82