From 201a62d7c9c882f10a0c15f393f613b56ecc7d89 Mon Sep 17 00:00:00 2001
From: Martin Diehl <mail@martin-diehl.net>
Date: Tue, 27 Oct 2020 13:19:53 +0100
Subject: [PATCH] easier visualization if verts have a point-cell

---
 python/damask/_vtk.py                   | 16 ++++++++++++----
 python/tests/reference/VTK/polyData.vtp | 10 +++++-----
 2 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/python/damask/_vtk.py b/python/damask/_vtk.py
index c1fe52f38..546ff4c88 100644
--- a/python/damask/_vtk.py
+++ b/python/damask/_vtk.py
@@ -108,11 +108,18 @@ class VTK:
             Spatial position of the points.
 
         """
+        N = points.shape[0]
         vtk_points = vtk.vtkPoints()
         vtk_points.SetData(np_to_vtk(points))
 
+        vtk_cells = vtk.vtkCellArray()
+        vtk_cells.SetNumberOfCells(N)
+        vtk_cells.SetCells(N,np_to_vtkIdTypeArray(np.stack((np.ones  (N,dtype=np.int64),
+                                                            np.arange(N,dtype=np.int64)),axis=1).ravel(),deep=True))
+
         vtk_data = vtk.vtkPolyData()
         vtk_data.SetPoints(vtk_points)
+        vtk_data.SetVerts(vtk_cells)
 
         return VTK(vtk_data)
 
@@ -164,6 +171,7 @@ class VTK:
 
         return VTK(vtk_data)
 
+
     @staticmethod
     def _write(writer):
         """Wrapper for parallel writing."""
@@ -192,7 +200,7 @@ class VTK:
         default_ext = writer.GetDefaultFileExtension()
         ext = Path(fname).suffix
         if ext and ext != '.'+default_ext:
-            raise ValueError(f'Given extension {ext} does not match default .{default_ext}')
+            raise ValueError(f'Given extension "{ext}" does not match default ".{default_ext}"')
         writer.SetFileName(str(Path(fname).with_suffix('.'+default_ext)))
         if compress:
             writer.SetCompressorTypeToZLib()
@@ -238,10 +246,10 @@ class VTK:
                       else data).reshape(N_data,-1),deep=True)                               # avoid large files
             d.SetName(label)
 
-            if   N_data == N_cells:
-                self.vtk_data.GetCellData().AddArray(d)
-            elif N_data == N_points:
+            if   N_data == N_points:
                 self.vtk_data.GetPointData().AddArray(d)
+            elif N_data == N_cells:
+                self.vtk_data.GetCellData().AddArray(d)
             else:
                 raise ValueError(f'Cell / point count ({N_cells} / {N_points}) differs from data ({N_data}).')
         elif isinstance(data,pd.DataFrame):
diff --git a/python/tests/reference/VTK/polyData.vtp b/python/tests/reference/VTK/polyData.vtp
index 6ed05f67f..dc4b5f149 100644
--- a/python/tests/reference/VTK/polyData.vtp
+++ b/python/tests/reference/VTK/polyData.vtp
@@ -1,7 +1,7 @@
 <?xml version="1.0"?>
 <VTKFile type="PolyData" version="0.1" byte_order="LittleEndian" header_type="UInt32" compressor="vtkZLibDataCompressor">
   <PolyData>
-    <Piece NumberOfPoints="10" NumberOfVerts="0" NumberOfLines="0" NumberOfStrips="0" NumberOfPolys="0">
+    <Piece NumberOfPoints="10" NumberOfVerts="10" NumberOfLines="0" NumberOfStrips="0" NumberOfPolys="0">
       <PointData>
         <DataArray type="Float32" Name="coordinates" NumberOfComponents="3" format="binary" RangeMin="0.7453560147132696" RangeMax="2.449489742783178">
           AQAAAACAAAB4AAAAVgAAAA==eF5jYICBhv2WfY9tLfuS7Ypk3PeDaCDf7okF3/7Vq1bZrV6lZQ+k94HEgHL2QHovUM7+iUUfiG0LlQdhkH77Ipnj9iB5qFp7kBjQDiBmcADRANsaLXM=
@@ -31,11 +31,11 @@
         </DataArray>
       </Points>
       <Verts>
-        <DataArray type="Int64" Name="connectivity" format="binary" RangeMin="1e+299" RangeMax="-1e+299">
-          AAAAAACAAAAAAAAA
+        <DataArray type="Int64" Name="connectivity" format="binary" RangeMin="0" RangeMax="9">
+          AQAAAACAAABQAAAAIgAAAA==eF4txbcBACAIADAsiP7/sAPJkog2PL28nT4uXz9/BXgALg==
         </DataArray>
-        <DataArray type="Int64" Name="offsets" format="binary" RangeMin="1e+299" RangeMax="-1e+299">
-          AAAAAACAAAAAAAAA
+        <DataArray type="Int64" Name="offsets" format="binary" RangeMin="1" RangeMax="10">
+          AQAAAACAAABQAAAAIgAAAA==eF4txbcBACAIADA76v8HM5As6a0MTy9vH4evn78TBzAAOA==
         </DataArray>
       </Verts>
       <Lines>