def SetDrawingDefaults(drawingData):
    """Add required items into data['drawing'] array if not present. This does not add
    all the items in SetupDrawingData, but it seems that this is not a problem. Perhaps the
    two routines could be combined?
    """
    defaultDrawing = {'viewPoint': [[0.5, 0.5, 0.5], []], 'showHydrogen': 
        True, 'backColor': [0, 0, 0], 'depthFog': False, 'Zclip': 50.0,
        'cameraPos': 50.0, 'Zstep': 0.5, 'radiusFactor': 0.85,
        'contourLevel': 1.0, 'bondRadius': 0.1, 'ballScale': 0.33,
        'vdwScale': 0.67, 'ellipseProb': 50, 'sizeH': 0.5, 'unitCellBox': 
        True, 'showABC': True, 'selectedAtoms': [], 'Atoms': [], 'oldxy': [
        ], 'magMult': 1.0, 'bondList': {}, 'viewDir': [1, 0, 0], 'Plane': [
        [0, 0, 1], False, False, 0.0, [255, 255, 0]]}
    for key in defaultDrawing:
        if key not in drawingData:
            drawingData[key] = defaultDrawing[key]
