By removing the ability to have multiple CellSets in a DataSet
we can simplify the following things:
- Cell Fields now don't require a CellSet name when being constructed
- Filters don't need to manage what the active cellset is
For polygon cell shapes (that are not triangles or quadrilaterals),
interpolations are done by finding the center point and creating a
triangle fan around that point. Previously, the gradient was computed in
the same way as interpolation: identifying the correct triangle and
computing the gradient for that triangle.
The problem with that approach is that makes the gradient discontinuous
at the boundaries of this implicit triangle fan. To make things worse,
this discontinuity happens right at each vertex where gradient
calculations happen frequently. This means that when you ask for the
gradient at the vertex, you might get wildly different answers based on
floating point imprecision.
Get around this problem by creating a small triangle around the point in
question, interpolating values to that triangle, and use that for the
gradient. This makes for a smoother gradient transition around these
internal boundaries.
1f8030a6e Add non-const version of DataSet::Get methods
69226803c Make PointTransform actually transform the points
Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Robert Maynard <robert.maynard@kitware.com>
Merge-request: !1803
Once #377 is implemented we won't need this, but for now we have to
use the serial connectivity tables while validating the OrientNormals
output. Ensure that the serial device can be used during the validation
stage.
The primary (likely only) use of PointTransform is to perform affine
transform on the position of the mesh. However, PointTransform did not
actually move the mesh. Rather, it just created a new field with the
transformed points.
Now, the output has its coordinate system replaced with the transformed
one generated (in addition to be added as a field). This can be turned
off (but defaults to on).
Also changed the constructor to turn on UseCoordinateSystemAsField so
that by default the filter operates on the existing coordinate system
and replaces it with the new coordinate system.
Also removed the template parameter on the filter. That added an
unnecessary complication to using it.
3eb91af96 Use ArrayGetValue where possible in worklets.
Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Robert Maynard <robert.maynard@kitware.com>
Merge-request: !1799
Replace code such as `myArray.GetPortalControl().Get(0)` with
`vtkm::cont::ArrayGetValue(0, myArray)`, which will just retrieve
the single value without transferring the entire contents of
`myArray` to the host. This should prevent memory thrashing.
Also did some general style clean-ups and fixed loops that called
`GetPortalControl` in the loop body.
709b12c5b Add checks for size of contour worklet outputs
a3131d4e1 Fix bad normals in contour test
Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Li-Ta Lo <ollie@lanl.gov>
Merge-request: !1794
The contour worklet test was experiencing normals that were set to NaN
due to problems with computing the gradient of the original field. It
was determined that the problem was caused by the clip filter creating
degenerate cells because the clip plane exactly intersected the points
of the mesh. Although a problem, we found that this behavior also exists
in existing tools like ParaView and VisIt. Thus, it sounds like a
problem to be pushed off to a later day. Instead, just move the plane a
little bit to get it into general position.
Perhaps a better title for this change would be "Make the Threshold
filter not totally useless."
A long standing issue with the Threshold filter is that its output
CellSet was stored in a CellSetPermutation. This made Threshold hyper-
efficient because it required hardly any data movement to implement.
However, the problem was that any other unit that had to use the CellSet
failed. To have VTK-m handle that output correctly in other filters and
writers, they all would have to check for the existance of
CellSetPermutation. And CellSetPermutation is templated on the CellSet
type it is permuting, so all units would have to compile special cases
for all these combinations. This is not likely to be feasible in any
static solution.
The simple solution, implemented here, is to deep copy the cells to a
CellSetExplicit, which is a known type that is already used everywhere
in VTK-m. The solution is a bit disappointing since it requires more
memory and time to build. But it is on par with solutions in other
libraries (like VTK). And it really does not matter how efficient the
old solution was if it was useless.
The gradient is malformed at the apex of a pyramid. To get around this,
steal a trick from the VTK source where in this case interpolate some
values a little bit into the interior of the cell.
Also expand the gradient worklet tests to include all cell types.
