[vtkusers] Visualizing Sparse, Structured data in VTK

[Roland Gaboury]

Greetings.  I have a set of data which are organized into cylindrical
geometry... radial spacing of points is constant.  Angular spacing of
radials is (mostly) constant.  Distance between layers is not necessarily
constant, but it can be managed.

The problem:  As the complexity of the model is increased (radially), the
spacing between two radials increases until a threshold is reached, and a
new intermediate radial is spawned from the two base radials... and this
happens again as the radial threshold is crossed again. This is done to
reduce the memory consumed by the model.

The challenge:  I want to reconstruct these data as a 3D volume.  It has
been suggested that the data obey a Structured Grid method, but a structured
grid implies a data point for each and every point in the structured grid...
which means filling in all the intermediate radial data points with some
data, presumably interpolating, so that ALL radials are filled.  This
defeats the purpose of having interpolated radials in the first place, and
sucks up potentially a LOT more resources than we'd like to use... and
thirdly it represents unnecessary processing that nobody really wants to do.

Alternatively, we could compose an unstructured grid from the data, but by
the time I read the data, all I have are arrays of X-Y-Z coords for each of
the data points, plus the scalar data associated with each point (that's the
storage format).  Can anyone suggest the most reasonable approach for
reconstructing the volume from  these data?

Roland Gaboury
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