Hi Noah, > ... > • The solution on any given element is smooth, represented by arbitrary > order polynomials and sampled at surface and interior node locations. I tend > to use high order elements compared to typical practice, i.e. 7th, 8th, > 9th-order. I’d like the visualization to capture some of the element’s > internal solution structure rather than just a linear interpolation between > element vertices.
If you are dealing with meshes where regular sampling of higher order elements is feasible and the number of samples per element per axis is high (>8?), you might consider using composite datasets (AMR or multiblock datasets), with each block holding image data for a single element. > • The solution is multi-valued at faces where two elements are adjacent > and I want the visualization to well-capture the surface discontinuity. That can be troublesome with precisely coincident grid points since rendering just those boundaries will exhibit z-fighting. If you isocontour, you will see cracks at element boundaries which reflect discontinuities. A better understanding of what you intend to visualize might help decide how to organize the data. > ... Obviously ParaView is focused on 2D and 3D data. The underlying VTK looks > to only handle up to 3D vertex position vectors, for example. My takeaway > from this, is it is not possible to describe a 4D or higher mesh to ParaView > directly. No. > ... My survey of the documentation makes me think that I’ll be able to > provide parameters to the reader plugin that control the dataset. For > example, specify what dimensions to slice and where to slice. I suppose I > need to similarly parameterize the load of the mesh. Does this sound like a > workable approach? Yes. You may also want to take a look at http://www.vtk.org/Wiki/VTK/InSituDataStructures and vtkTypedDataArray as a way to provide 3-d point coordinates from a higher-dimensional array (and the remaining dimensions as other independent arrays). But it's unclear to me -- assuming you regularly sample phase space the same way you sample positional space -- how you would handle places where the projection to a subset of those dimensions resulted in coincident elements in the projected space. > For the data discontinuities at element faces, I’ve seen discussions in this > forum that suggest unstructured grids with duplicated/co-located vertices > allows for assigning two different data values at the same physical location. > Since I am working with structured grids and data, I’m wondering if a > different technique might work. How about inserting zero-volume collapsed > elements between each real element? I think this would be problematic for many VTK filters. > Lastly, for the high order visualization, ... the most straight forward > approach is to interpolate my structured high order elements... > vtkBridgeDataSet has been mentioned as a possible approach but requiring much > development effort. That was several years ago. Has there been any progress > by others with similar high-order or spectral data sets? Sadly, no. Although we have had a lot of interest from academia, there haven't been paying customers for this. David _______________________________________________ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the ParaView Wiki at: http://paraview.org/Wiki/ParaView Follow this link to subscribe/unsubscribe: http://www.paraview.org/mailman/listinfo/paraview
