[vtkusers] vtkWeb - sending data to the client

[Sebastien Jourdain]

Thinks serialization... And don't assume any specific efficiency. Think on
what you want to get on the JavaScript side.

On Tue, Oct 11, 2016 at 11:03 AM, Dan Lipsa <dan.lipsa at kitware.com> wrote:

> Thanks Seb,
> So I'll have to make regular arrays out of the numpy arrays and send those
> over?
> What about multi-dimensional numpy arrays? (2D, 3D) Do I have to flatten
> them on the server and then get them into the right format on the client?
>
> What about the numpy masked arrays? This have missing values, similar with
> VTK blanking.
>
> How efficient is this?
>
> Thanks,
> Dan
>
>
> On Fri, Oct 7, 2016 at 5:27 PM, Sebastien Jourdain <
> sebastien.jourdain at kitware.com> wrote:
>
>> We do that all the time, so yes, vtk/paraview web can handle it.
>>
>> Just need to create a new RPC method that will build the structure the
>> client expect based on its request.
>>
>> Here is a ParaView example which should apply to VTK if you ignore the
>> ParaView proxy magic (self.reader.GetClientSideObject())
>>
>>     @exportRpc("my.super.app.get.table")
>>     def getTable(self):
>>         from vtk.util.numpy_support import vtk_to_numpy
>>         returnValue = {}
>>         dataTable = self.reader.GetClientSideObjec
>> t().GetOutputDataObject(0)
>>         count = dataTable.GetNumberOfColumns()
>>         for idx in range(count):
>>             array = dataTable.GetColumn(idx)
>>             if SUPPORTED_TYPES[VTK_DATA_TYPES[array.GetDataType()]]:
>>                 npArray = vtk_to_numpy(array)
>>                 returnValue[array.GetName()] = [ i.item() for i in
>> npArray ]
>>             else:
>>                 returnValue[array.GetName()] = [ array.GetValue(i) for i
>> in xrange(array.GetNumberOfValues()) ]
>>         return returnValue
>>
>> with that for our constant settings for filtering arrays we don't want to
>> get on the client side.
>>
>> VTK_DATA_TYPES = [ 'void',            # 0
>>                    'bit',             # 1
>>                    'char',            # 2
>>                    'unsigned_char',   # 3
>>                    'short',           # 4
>>                    'unsigned_short',  # 5
>>                    'int',             # 6
>>                    'unsigned_int',    # 7
>>                    'long',            # 8
>>                    'unsigned_long',   # 9
>>                    'float',           # 10
>>                    'double',          # 11
>>                    'id_type',         # 12
>>                    'unspecified',     # 13
>>                    'unspecified',     # 14
>>                    'signed_char' ]    # 15
>>
>> SUPPORTED_TYPES = { 'void': False,
>>                    'bit': False,
>>                    'char': True,
>>                    'unsigned_char': True,
>>                    'short': True,
>>                    'unsigned_short': True,
>>                    'int': True,
>>                    'unsigned_int': True,
>>                    'long': True,
>>                    'unsigned_long': True,
>>                    'float': True,
>>                    'double': True,
>>                    'id_type': True,
>>                    'unspecified': False,
>>                    'unspecified': False,
>>                    'signed_char': True }
>>
>> On Fri, Oct 7, 2016 at 3:09 PM, Dan Lipsa <dan.lipsa at kitware.com> wrote:
>>
>>> Hi Seb and all,
>>> One of the features we want to implement in our application is the
>>> ability to render plots on the client (in certain cases) using alternate
>>> means such as plotly.
>>>
>>> For this we need to send data = a numpy or numpy masked array = to the
>>> client. Is there any capability in vtkWeb or do you have any advise on how
>>> to do that?
>>>
>>> Thanks,
>>> Dan
>>>
>>>
>>
>
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