VTK polishing

avoid segmentation fault (also allows testing)

python/damask/__init__.py

@@ -21,8 +21,8 @@ from ._rotation        import Rotation         # noqa
 from ._crystal         import Crystal          # noqa
 from ._orientation     import Orientation      # noqa
 from ._table           import Table            # noqa
-from ._vtk             import VTK              # noqa
 from ._colormap        import Colormap         # noqa
+from ._vtk             import VTK              # noqa
 from ._config          import Config           # noqa
 from ._configmaterial  import ConfigMaterial   # noqa
 from ._grid            import Grid             # noqa

python/damask/_grid.py

@@ -674,7 +674,7 @@ class Grid:
 
     def show(self) -> None:
         """Show on screen."""
-        VTK.from_rectilinear_grid(self.cells,self.size,self.origin).show()
+        VTK.from_image_data(self.cells,self.size,self.origin).show()
 
 
     def add_primitive(self,

python/damask/_vtk.py

@@ -442,22 +442,24 @@ class VTK:
 
         mapper = vtk.vtkDataSetMapper()
         mapper.SetInputData(self.vtk_data)
+
         actor = vtk.vtkActor()
         actor.SetMapper(mapper)
+        actor.GetProperty().SetColor(230/255,150/255,68/255)
 
         ren = vtk.vtkRenderer()
+        ren.AddActor(actor)
+        ren.SetBackground(67/255,128/255,208/255)
 
         window = vtk.vtkRenderWindow()
         window.AddRenderer(ren)
-
-        ren.AddActor(actor)
-        ren.SetBackground(0.2,0.2,0.2)
-
         window.SetSize(width,height)
+        window.SetWindowName(util.execution_stamp('VTK','show'))
 
         iren = vtk.vtkRenderWindowInteractor()
         iren.SetRenderWindow(window)
-
-        iren.Initialize()
+        if os.name == 'posix' and 'DISPLAY' not in os.environ:
+            print('Found no rendering device')
+        else:
             window.Render()
             iren.Start()

python/tests/test_VTK.py

@@ -28,6 +28,10 @@ class TestVTK:
     def _patch_execution_stamp(self, patch_execution_stamp):
         print('patched damask.util.execution_stamp')
 
+    def test_show(sef,default,monkeypatch):
+        monkeypatch.delenv('DISPLAY',raising=False)
+        default.show()
+
     def test_rectilinearGrid(self,tmp_path):
         cells  = np.random.randint(5,10,3)*2
         size   = np.random.random(3) + 1.0