[VTK] Various fix

panel/pane/vtk/synchronizable_serializer.py

@@ -744,6 +744,7 @@ def lookupTableSerializer(parent, lookupTable, lookupTableId, context, depth):
         'properties': {
             'numberOfColors': lookupTable.GetNumberOfColors(),
             'valueRange': lookupTableRange,
+            'range': lookupTableRange,
             'hueRange': lookupTableHueRange,
             # 'alphaRange': lutAlphaRange,  # Causes weird rendering artifacts on client
             'saturationRange': lutSatRange,

panel/pane/vtk/vtk.py

@@ -218,7 +218,7 @@ def __init__(self, object, **params):
 
     @classmethod
     def applies(cls, obj, **kwargs):
-        if 'vtk' not in sys.modules:
+        if 'vtk' not in sys.modules and 'vtkmodules' not in sys.modules:
             return False
         else:
             import vtk
@@ -230,25 +230,36 @@ def get_renderer(self):
         """
         return list(self.object.GetRenderers())[0]
 
-    def get_color_mappers(self):
-        cmaps = []
-        for view_prop in self.get_renderer().GetViewProps():
-            if view_prop.IsA('vtkScalarBarActor'):
-                rgba_arr = np.frombuffer(
-                    memoryview(view_prop.GetLookupTable().GetTable()), 
-                    dtype=np.uint8
-                ).reshape((-1, 4))
-                palette = [self._rgb2hex(*rgb) for rgb in rgba_arr[:,:3]]
-                low, high = view_prop.GetLookupTable().GetTableRange()
-                name = view_prop.GetTitle()
-                cmaps.append(
-                    LinearColorMapper(low=low, high=high, name=name, palette=palette)
-                )
+    def _vtklut2bkcmap(self, lut, name):
+        table = lut.GetTable()
+        low, high = lut.GetTableRange()
+        rgba_arr =  np.frombuffer(memoryview(table),  dtype=np.uint8).reshape((-1, 4))
+        palette = [self._rgb2hex(*rgb) for rgb in rgba_arr[:,:3]]
+        return LinearColorMapper(low=low, high=high, name=name, palette=palette)
+
+    def get_color_mappers(self, infer=False):
+        if not infer:
+            cmaps = []
+            for view_prop in self.get_renderer().GetViewProps():
+                if view_prop.IsA('vtkScalarBarActor'):
+                    name = view_prop.GetTitle()
+                    lut = view_prop.GetLookupTable()
+                    cmaps.append(self._vtklut2bkcmap(lut, name))
+        else:
+            infered_cmaps = {}
+            for actor in self.get_renderer().GetActors():
+                mapper = actor.GetMapper()
+                cmap_name = mapper.GetArrayName()
+                if cmap_name and cmap_name not in infered_cmaps:
+                    lut = mapper.GetLookupTable()
+                    infered_cmaps[cmap_name] = self._vtklut2bkcmap(lut, cmap_name)
+            cmaps = infered_cmaps.values()
         return cmaps
 
     @param.depends('color_mappers')
-    def _construct_colorbars(self):
-        color_mappers = self.color_mappers
+    def _construct_colorbars(self, color_mappers=None):
+        if not color_mappers:
+            color_mappers = self.color_mappers
         from bokeh.models import Plot, ColorBar, FixedTicker
         cbs = []
         for color_mapper in color_mappers:
@@ -264,8 +275,13 @@ def _construct_colorbars(self):
         [plot.add_layout(cb, 'below') for cb in cbs]
         return plot
 
-    def construct_colorbars(self):
-        return Pane(self._construct_colorbars)
+    def construct_colorbars(self, infer=True):
+        if infer:
+            color_mappers = self.get_color_mappers(infer)
+            return Pane(self._construct_colorbars(color_mappers))
+        else:
+            return Pane(self._construct_colorbars)
+
 
     def export_scene(self, filename='vtk_scene'):
         if '.' not in filename:
@@ -306,6 +322,7 @@ def _serialize_ren_win(self, ren_win, context, binary=False, compression=True, e
         import panel.pane.vtk.synchronizable_serializer as rws
         if exclude_arrays is None:
             exclude_arrays = []
+        store_offscreen_rendering = ren_win.GetOffScreenRendering()
         ren_win.OffScreenRenderingOn() # to not pop a vtk windows
         ren_win.Modified()
         ren_win.Render()
@@ -314,6 +331,8 @@ def _serialize_ren_win(self, ren_win, context, binary=False, compression=True, e
         arrays = {name: context.getCachedDataArray(name, binary=binary, compression=compression)
                     for name in context.dataArrayCache.keys() 
                     if name not in exclude_arrays}
+        ren_win.Finalize()
+        ren_win.SetOffScreenRendering(store_offscreen_rendering)
         return scene, arrays
 
     @staticmethod

panel/tests/pane/test_vtk.py

@@ -262,9 +262,14 @@ def test_vtk_pane_more_complex(document, comm, tmp_path):
     assert isinstance(model, VTKSynchronizedPlot)
     assert pane._models[model.ref['id']][0] is model
 
-    colorbars = pane.construct_colorbars().object()
-    assert len(colorbars.below) == 3
-    assert all(isinstance(cb, ColorBar) for cb in colorbars.below)
+    colorbars_infered = pane.construct_colorbars().object
+
+    assert len(colorbars_infered.below) == 2 # infer only actor color bars
+    assert all(isinstance(cb, ColorBar) for cb in colorbars_infered.below)
+
+    colorbars_in_scene = pane.construct_colorbars(infer=False).object()
+    assert len(colorbars_in_scene.below) == 3
+    assert all(isinstance(cb, ColorBar) for cb in colorbars_in_scene.below)
     # add axes
     pane.axes = dict(
         origin = [-5, 5, -2],