[Paraview] Coloring isocontour by the coordinates outputted from a Transform filter and some other questions

[Shuhao Wu]

Hello Cory,

Thanks for the advice. I will give this a shot. Are there also 
documentations to create custom filters? Not just ProgrammableFilters, 
but full on filters in something like a .py file (or any other language) 
that can be easily reused?

This will allow me to perform the transformation, expose the 
coordinates, and perform the clipping operations all in one step, which 
in theory should reduce the computational time and memory required as 
there would not be excessive amount copying between each stage of the 
pipeline.

I am only asking this because my dataset consists of ~30million nodes 
each time step and paraview runs somewhat slowly on my computer, taking 
about 30-70s to process a single timestamp in order to generate an image.

Thanks,
Shuhao

On 07/09/2017 09:11 PM, Cory Quammen wrote:
> Shuhao,
> 
> Unfortunately, the tooltips for the clip function parameters do not
> appear to be working (I filed bug
> https://gitlab.kitware.com/paraview/paraview/issues/17593 describing
> the problem).
> 
> It turns out the properties for the Box clip type are defined in a way
> that is a bit trickier than I thought. They are relative to the
> bounding box of the input data:
> 
> * Position - center of the box function relative to the center of the
> input dataset bounding box
> * Rotation - Eulerian angles about the X, Y, and Z axes describing the
> rotation of the bounding box
> * Scale - non-uniform scale factor applied in x, y, and z relative to
> the input dataset bounding box
> 
> Given how these items are defined, it will actually really be a pain
> to compute the properties for an arbitrary x-, y-, and z-range.
> 
> The way you described earlier with a cascade of Calculator and
> Threshold filters will work. Another way would be to use a single
> Python Calculator with the expression
> 
> numpy.all((xmin <= inputs[0].Points[:,0], inputs[0].Points[:,0] <=
> xmax, ymin <= inputs[0].Points[:,1], inputs[0].Points[:,1] <= ymax,
> zmin <= inputs[0].Points[:,2], inputs[0].Points[:,2] <= zmax),
> axis=0).astype('int')
> 
> and then Threshold by the result, which will be 0 outside [xmin, xmax,
> ymin, ymax, zmin, zmax] and 1 inside it.
> 
> Thanks,
> Cory
> 
> 
> 
> On Fri, Jul 7, 2017 at 10:51 AM, Shuhao Wu <shuhao at shuhaowu.com> wrote:
>> Is there documentation on how the Box clip type work? I'm not quite sure how
>> to do the math to convert the threshold values to the position/scale values.
>>
>> Thanks,
>> Shuhao
>>
>>
>> On 2017-07-03 10:03 AM, Cory Quammen wrote:
>>>
>>> On Tue, Jun 20, 2017 at 9:33 PM, Shuhao Wu <shuhao at shuhaowu.com> wrote:
>>>
>>>> Hello Cory,
>>>>
>>>> I've been playing around a little bit more and followed your suggestion
>>>> with using the calculator to "expose" the transformed coordinates.
>>>> However,
>>>> my understanding is that this Calculator will duplicate the memory usage
>>>> for that coordinate and be an additional step in the filtering process,
>>>> slowing it down.
>>>
>>>
>>>
>>> Yes, that's true unfortunately. By the way, if you need X, Y, and Z, you
>>> can use one Calculator filter to produce all three with the expression
>>>
>>> iHat*coordsX + jHat*coordsY + kHat*coordsZ
>>>
>>> This produces a 3-component array - you can then color your isosurface by
>>> just one of the components or by the magnitude.
>>>
>>> I have to use the Calculator filter to expose all 3 coordinates before
>>>>
>>>> using a threshold to filter for only a subset region that I want to plt,
>>>> which results in a filtering chain as follows:
>>>>
>>>> ExposeX (Calculator) -> ExposeY (Calculator) -> ExposeZ (Calculator) ->
>>>> ThresholdX (Threshold) -> ThresholdY (Threshold) -> ThresholdZ
>>>> (Threshold).
>>>
>>>
>>>
>>>>
>>> This is 6 filters, which is very slow with my data set (>29M nodes in a
>>>>
>>>> rectlinear grid). Is there a way to speed this up?
>>>>
>>>>
>>> You could instead use a Clip filter with Clip Type set to Box. You have to
>>> do a little math to convert from your threshold values to the box Scale
>>> and
>>> Position properties, but it shouldn't be too bad, and will make your
>>> pipeline simpler and faster.
>>>
>>> Cory
>>>
>>>
>>>> Thanks,
>>>> Shuhao
>>>>
>>>>
>>>> On 2017-06-07 03:29 PM, Cory Quammen wrote:
>>>>
>>>>> Shuhao,
>>>>>
>>>>> Welcome to ParaView!
>>>>>
>>>>> On Sun, Jun 4, 2017 at 6:33 PM, Shuhao Wu <shuhao at shuhaowu.com> wrote:
>>>>>
>>>>>> Hello all,
>>>>>>
>>>>>> Is there a way to color an isocontour via the coordinates outputted
>>>>>> from
>>>>>> a
>>>>>> Transform filter? I'm using the Transform filter to "normalize" my
>>>>>> coordinate systems and I want to display the isocontour colored by the
>>>>>> normalized Y coordinates. Do I have to create yet another Calculator
>>>>>> filter
>>>>>> to recalculate the normalized Y value that is already calculated by the
>>>>>> Transform filter?
>>>>>>
>>>>>
>>>>> There is currently no direct way to color surfaces by coordinate
>>>>> value. You can, however, add a Calculator after the Transform filter
>>>>> and simply set the expression to coordsY - no recomputation of the
>>>>> normalization is needed. This will copy your normalized Y coordinate
>>>>> values to a new array named "Result", and you can then color the
>>>>> isosurface by "Result". "Result" is just the default name - you can
>>>>> change it however you wish.
>>>>>
>>>>> Also: is there a way to turn off one axis on the axis grid (so turn off
>>>>>>
>>>>>> the
>>>>>> Y axis display and leave only X and Z)?
>>>>>>
>>>>>
>>>>> Click the Edit button next to the Axes Grid option. Click the gear
>>>>> icon in the top right of the dialog that appears. Under Face
>>>>> Properties, click on the "Faces to Render" combo box. Turn off the
>>>>> sides you do not wish to see by selecting them in the combo box.
>>>>>
>>>>> What about changing the interval on
>>>>>>
>>>>>> the axis itself (instead of incrementing by 100 as it chooses,
>>>>>> increment
>>>>>> by
>>>>>> 250).
>>>>>>
>>>>>
>>>>> In the same dialog described above, check the "X Axis Use Custom
>>>>> Labels", and you can specify exactly the labels you want. There is no
>>>>> property to directly change the increment.
>>>>>
>>>>> Best,
>>>>> Cory
>>>>>
>>>>> I'm pretty new to Paraview (coming from Tecplot). Please bear with me as
>>>>> I
>>>>>>
>>>>>> likely will have more question.
>>>>>>
>>>>>> Thanks,
>>>>>> Shuhao
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>>>>>
>>>>>
>>>>>
>>>>>
>>>
>>>
>>
> 
> 
>