[postprocessing] Add pvpython script to export 2d screenshots

bin/postprocessing/exportscreenshot2d.py

+#### TODO:
+# - different colors for legend
+# - read-in pvds with time outputs
+# - read-in multiple vtus, e.g. for multidomain
+# - rendering method 2d and 3d
+
+# parse arguments
+import argparse
+import os
+import sys
+
+bool = ['True','False']
+parameterType = ['CELLS','POINTS']
+legendOrientation = ['Horizontal','Vertical']
+parser = argparse.ArgumentParser(
+  prog='\033[1m\033[94m' + 'pvbatch' + '\033[0m' + ' ' + sys.argv[0],
+  description='Export a screenshot of a standard 2D plot. To change the color palette, change the default in the paraview GUI.'
+)
+# on/off-type features
+feature_parser = parser.add_mutually_exclusive_group(required=False)
+feature_parser.add_argument('--offscreen', dest='offscreen', action='store_true', help='Enable offscreen rendering (large pixel size)')
+feature_parser.add_argument('--no-offscreen', dest='offscreen', action='store_false', help='Disable offscreen rendering (low pixel sizes)')
+parser.set_defaults(offscreen=False)
+feature_parser.add_argument('--showAxesGrid', dest='showAxesGrid', action='store_true', help='Show the axes grid for the domain')
+feature_parser.add_argument('--no-showAxesGrid', dest='showAxesGrid', action='store_false', help='Do not show the axes grid for the domain')
+parser.set_defaults(showAxesGrid=False)
+feature_parser.add_argument('--showLegend', dest='showLegend', action='store_true', help='Show the parameter legend/range')
+feature_parser.add_argument('--no-showLegend', dest='showLegend', action='store_false', help='Do not show the parameter legend/range')
+parser.set_defaults(showLegend=True)
+feature_parser.add_argument('--showOrientationAxes', dest='showOrientationAxes', action='store_true', help='Show the orientation axis')
+feature_parser.add_argument('--no-showOrientationAxes', dest='showOrientationAxes', action='store_false', help='Do not the orientation axis')
+parser.set_defaults(showOrientationAxes=False)
+# more complicated features
+parser.add_argument('-f', '--files', nargs='+', required=True, help="vtu files to be processed")
+parser.add_argument('-o', '--outputDirectory', default='', help="Directory to which the pcitures are written")
+parser.add_argument('-of', '--outFile', default='', help="Basename of the written png file")
+parser.add_argument('-p', '--parameter', default='', help='The name of the parameter to be plotted')
+parser.add_argument('-pc', '--parameterComponent', type=int, default=-1, help='Plot only a specific component of a vector (default: magnitude=-1)')
+parser.add_argument('-pr', '--parameterRange', type=float, nargs=2, default=[0, 0], help='Adjustment of the color rane (default: min/max)')
+parser.add_argument('-pt', '--parameterType', choices=parameterType, default='CELLS', help='The type of the data field (CELLS or POINTS)')
+parser.add_argument('-lo', '--legendOrientation', choices=legendOrientation, default='Horizontal', help='The name of the parameter to be plotted')
+parser.add_argument('-lp', '--legendPosition', type=float, nargs=2, default=[0.25, 0.0], help='The position of the legend')
+parser.add_argument('-lz', '--legendZoom', type=float, nargs=2, default=[0.5, 0.5], help='The zoom of the legend')
+parser.add_argument('--size', type=int, nargs=2, default=[600, 400], help="The pixel size of the png file (default: 600x400)")
+parser.add_argument('--scale', type=float, nargs=3, default=[1.0, 1.0, 1.0], help="Scaling factors in each direction")
+parser.add_argument('-v', '--verbosity', type=int, default=2, help='Verbosity of the output')
+args = vars(parser.parse_args())
+
+try:
+    from paraview.simple import *
+except ImportError:
+    print("`paraview.simple` not found. Make sure using pvbatch.")
+
+# import locations
+commonOutDirectory = False
+outDirectory = args['outputDirectory']
+if not outDirectory == '':
+    outDirectory += '/'
+    commonOutDirectory = True
+    if not os.path.exists(outDirectory):
+        os.makedirs(outDirectory)
+
+# loop over all vtu files
+counter = 1
+for curFile in args['files']:
+    # print progress to command line
+    fileWithoutPath = os.path.basename(curFile)
+    if not commonOutDirectory:
+        abspath = os.path.abspath(curFile)
+        outDirectory = os.path.dirname(abspath) + '/'
+    basename = os.path.splitext(fileWithoutPath)[0]
+    if args['verbosity'] == 1:
+        print("Processing file ({}/{}): {}".format(counter, len(args['files']), fileWithoutPath))
+    counter += 1
+
+    # read vtu file and print available parameters
+    vtuFile = XMLUnstructuredGridReader(FileName=curFile)
+    if args['parameter'] == '':
+        print "\nNo parameter was specified, use '-p PARAMETER' to specify it. Available parameters are:"
+        print vtuFile.CellArrayStatus
+        args['parameter'] = raw_input('Parameter: ')
+
+    # get active view
+    renderView1 = GetActiveView()
+    if not renderView1:
+        # When using the ParaView UI, the View will be present, not otherwise.
+        renderView1 = CreateRenderView()
+
+    # print additional help message for large picture sizes
+    if (args['size'][0] > 1024 or args['size'][1] > 1024) and args['offscreen'] == False:
+        print "\nIt seems like you want to export a picture greater then your actual screen size. Use:"
+        print "pvbatch --use-offscreen-rendering SCRIPT OPTIONS --offscreen"
+        exit(2)
+    renderView1.ViewSize = args['size']
+
+    if args['showOrientationAxes'] == False:
+        renderView1.OrientationAxesVisibility = 0
+
+    if args['showAxesGrid'] == True:
+        renderView1.AxesGrid.Visibility = 1
+
+    # show data in view
+    vtuFileDisplay = Show(vtuFile, renderView1)
+    vtuFileDisplay.Scale = args['scale']
+
+    # reset view to fit data
+    renderView1.ResetCamera()
+
+    # set scalar coloring
+    ColorBy(vtuFileDisplay, (args['parameterType'], args['parameter']))
+
+    # show color bar/color legend
+    if args['showLegend'] == True:
+        vtuFileDisplay.SetScalarBarVisibility(renderView1, True)
+
+    # get color transfer function/color map for the parameter
+    parameterLUT = GetColorTransferFunction(args['parameter'])
+
+    # plot only a specific vector component
+    if args['parameterComponent'] != -1:
+        parameterLUT.VectorMode = 'Component'
+        parameterLUT.VectorComponent = args['parameterComponent']
+        #if args['parameterRange'][0] == 0 and args['parameterRange'][1] == 0:
+            #vtuFileDisplay.RescaleTransferFunctionToDataRange(False)
+        if args['showLegend'] == True:
+            velocityLUTColorBar = GetScalarBar(parameterLUT, renderView1)
+            velocityLUTColorBar.Title = args['parameter']
+            velocityLUTColorBar.ComponentTitle = str(args['parameterComponent'])
+
+    # adjust the range of the legend
+    if args['parameterRange'][0] != 0 or args['parameterRange'][1] != 0:
+        mean = (args['parameterRange'][0] + args['parameterRange'][1]) / 2
+        parameterLUT.RGBPoints = [args['parameterRange'][0], 0.231373, 0.298039, 0.752941,
+                                  mean, 0.865003, 0.865003, 0.865003,
+                                  args['parameterRange'][1], 0.705882, 0.0156863, 0.14902]
+    if args['parameterRange'][0] == 0 and args['parameterRange'][1] == 0:
+        vtuFileDisplay.RescaleTransferFunctionToDataRange(False)
+
+    # the placement and size of the legend
+    legend = GetScalarBar(parameterLUT, renderView1)
+    legend.Position = args['legendPosition']
+    legend.Position2 = args['legendZoom']
+    legend.Orientation = args['legendOrientation']
+
+    # current camera placement for renderView1
+    renderView1.InteractionMode = '2D'
+    #renderView1.CameraPosition = [5.0, 0.12345, 0.0]
+    #renderView1.CameraFocalPoint = [5.0, 0.12345, 0.0]
+
+    # uncomment the following to render all views
+    RenderAllViews()
+    UseOffscreenRenderingForScreenshots = 1
+
+    # save screenshot
+    if not args['outFile'] == '':
+        basename = args['outFile']
+    SaveScreenshot(outDirectory + basename + '.png')