vtkMDEWHexahedronFactory: 4D case, allow specifying which position to slice at in the 4th dimension

[Janik Zikovsky]

The hexahedron factory allows slicing 4D cubes into 3D and right now it defaults to 4th dimension slice at t = 0.

A way to specify the T position in the GUI to display the cubes is needed; minor modifications to vtkMDEWHexahedronFactory are needed to pass through that value.

For iteration 31, probably.

Refs #3551

[Owen Arnold]

Same issue for many of the other vtkDataSet types especially after rebinning/collapsing a dimension down.

[Owen Arnold]

This feature is already present. Timestep values are picked up from the PV time/animation control. Time values are piped through to the vtkThresholdingUnstructuredGrid factory. If it is passed a 3D workspace then the vtkThresholdingUnstructuredGridFactory will identify it in it's initialize method and delegate to a successor. If a sucessor is set to be a vtkThresholdingHexahedronFactory (which handles 3D) then the timestep is of no concern. This happens when the time dimension is integrated.

Have I got this right, or is there some other use-case that I'm not considering?

[Janik Zikovsky]

I meant for the MDEW hexahedron display; the vtkThresholdingHexahedronFactory is only for a MDHistoWorkspace.

You can slice through the 4D of a MDEventWorkspace to show 3D and you could basically choose any "time" between the extents - it is not limited to a particular step because the recursive binning means you might have more detail at any other time. Therefore it seems like a slider would be a good way to go. Paraview's 'time' control with fixed number of steps is less well suited.

[Janik Zikovsky]

It does work (with a caveat of a PV bug)...

[Michael Reuter]

Yes, the time controls for PV are set to a fixed increment. The Animation view in ParaView may help you get closer to being able to repeat this.

[Stuart Campbell]

This ticket has been transferred to github issue ​4562