[Paraview] create representation to display 3 planes of image data

[FISSELL at pitt.edu]

Hi,

I would like to simultaneously view 3 planes (XY, YZ, XZ) of an image.
I made a Python macro to do this, but I think its clunky.

I think the right way to do this is to write a plugin representation
similar to
ImageSliceRepresentation but pulling out  3 slices.

-- Would a plugin representation be the right way to go ?
-- Documentation seems to discourage folks a little from messing
    with their own representations.  If it is the right way to go, is
    it feasible in ParaView right now ?  I am using 3.12-RC2.
-- To start, based on the MySpecialRepresentation example, I wrote
    a "OrthoSliceAlphaRepresentation" that subclasses
ImageSliceRepresentation
    but doesn't change anything, and I don't even substitute my own mapper
    at this point.  I made it a subproxy extending UniformGridRepresentation.
    It appears as a Rep. for image data, but the Slice selector in the
    display panel is greyed out.  Why is this ?  (Code snippets below).
-- For the real code I think I should not subclass ImageSliceRepresentation
   but copy/rename all that code and alter it, ie having
OrthoSliceAlphaRepresentation
   subclass  vtkPVDataRepresentation.  Is that the way you would do it ?

thanks
Kate


================= XML for OrthoSliceAlphaRepresentation, Slice widget is
not enabled ====
<ServerManagerConfiguration>

  <ProxyGroup name="representations">
    <RepresentationProxy name="OrthoSliceAlphaRepresentation"
      class="vtkOrthoSliceAlphaRepresentation"
      processes="client|renderserver|dataserver"
      base_proxygroup="representations"
      base_proxyname="ImageSliceRepresentation">
      <Documentation>
	Trying to make identical to Slice Representation
      </Documentation>
    </RepresentationProxy>


    <Extension name="UniformGridRepresentation">
      <Documentation>
        Extends standard UniformGridRepresentation by adding
        OrthoSliceAlphaRepresentation as a new type of representation.
      </Documentation>

      <RepresentationType subproxy="OrthoSliceAlphaRepresentation"
        text="OrthoSliceAlpha"   />

      <SubProxy>
        <Proxy name="OrthoSliceAlphaRepresentation"
          proxygroup="representations" proxyname="ImageSliceRepresentation">
        </Proxy>
        <ShareProperties subproxy="SliceRepresentation">
          <Exception name="Input" />
          <Exception name="Visibility" />
          <Exception name="Representation" />
        </ShareProperties>
      </SubProxy>
    </Extension>
  </ProxyGroup>

</ServerManagerConfiguration>
=======================================================================
vtkOrthoSliceAlphaRepresentation is defined like this, and no methods
written yet, just trying to inherit *everything* from
vtkImageSliceRepresentation

class VTK_EXPORT vtkOrthoSliceAlphaRepresentation : public
vtkImageSliceRepresentation
==========================================================================