Problem with clip in Paraview 5.8.0

Naeeme.dmo · September 17, 2020, 9:51am

Hi,

I have a script with a simple clip “Box” definition in pvpython which works fine on paraview 5.5. I have written compatibility commands on top of my script as defined below:
paraview.compatibility.major = 5
paraview.compatibility.minor = 5

The scripts works fine for paraview 5.6, too. When I use paraview 5.8.0, it runs with no error but produces no results.
The reason for it is that I have defined “.Bounds” attribute for my clip, which somehow does not work on this version of paraview. If for any reason I change the size of my bounding box array, I would get an error that it needs to have 6 entries, which makes me think paraview reads the bounds array correctly. But after reading, it does not apply it. When I checked the file in interactive mode on Paraview, I see that the clip definition is completely wrong. I changed the bounds to .Position+.Length definitions, and the script works perfectly.

I thought by defining compatibility commands on top of my python scripts, It would be possible to use them for newer versions of paraview. Am I missing out on something or is this a bug in this version (5.8) ?

Cheers,
Naeeme

mwestphal · September 17, 2020, 11:48am

It may be possible the retro compatibility got broken.

Did you try doing this manually in ParaView and using the trace ?

Naeeme.dmo · September 17, 2020, 5:23pm

Yes, indeed. But the clip box is somehow broken. It does not have any attribute in the trace and when I click on it the Position is [1e299 1e299 1e299] and the length is [1 1 1].

mwestphal · September 18, 2020, 7:37am

I just tried with 5.8.1 and it works great, I see this in the trace after applying :

# Properties modified on clip1.ClipType

clip1.ClipType.Length = [12.523610213744012, 20.0, 20.0]

# update the view to ensure updated data information

renderView1.Update()

Naeeme.dmo · September 22, 2020, 3:15pm

So I tried everything out and I still don’t get the same answer. Unfortunately I cannot share my codes, because they are confidential. As a simple test I wrote this script and ran it with Paraview5.5.0-RC3 and Paraview5.8.1. The result of the later are not correct.

#! /usr/bin/env python

import sys, math, time, os
paraview.compatibility.major = 5
paraview.compatibility.minor = 5
paraview.simple._DisableFirstRenderCameraReset()
case = Box()
RenderView = GetActiveViewOrCreate('RenderView')
ClipDef = Clip(Input=case, ClipType = 'Box')
ClipDef.ClipType.Position= [0.0, 0.0, 0.0]
ClipDef.ClipType.Bounds = [-100.,0.,-100.,100.,-100.,100.]
clippedcase = ClipDef
caseDisplay = GetDisplayProperties(clippedcase, view=RenderView) #Show Data in View

In my other codes, I also wrote out the trace for both paraview versions. And I see that the one for Paraview 5.8.1 is not correct. However, I can not explain why the definitions end up being interpreted so differently. I share with you the part of the trace related to the clipping. Please note that the input for both runs are identical. The only different is in python scripts: the later has python version 3.7 instead of 2.7 and has compatibility commands defined on top of all the files.

Paraview.5.5.0-RC3 (correct results):

clip1 = Clip(Input=groupDatasets1)
clip1.ClipType = 'Box'
clip1.Scalars = [None, '']
clip2 = Clip(Input=groupDatasets2)
clip2.ClipType = 'Box'
clip2.Scalars = [None, '']
clip2Display = Show(clip2, renderView1)
clip2Display.Representation = 'Surface'
clip2Display.ColorArrayName = [None, '']
clip2Display.DiffuseColor = [0.0, 0.0, 0.0]
clip2Display.BackfaceDiffuseColor = [0.0, 0.0, 0.0]
clip2Display.OSPRayScaleArray = 'VelocityP'
clip2Display.OSPRayScaleFunction = 'PiecewiseFunction'
clip2Display.SelectOrientationVectors = 'None'
clip2Display.ScaleFactor = 4.352999877929688
clip2Display.SelectScaleArray = 'None'
clip2Display.GlyphType = 'Arrow'
clip2Display.GlyphTableIndexArray = 'None'
clip2Display.GaussianRadius = 0.21764999389648437
clip2Display.SetScaleArray = ['POINTS', 'VelocityP']
clip2Display.ScaleTransferFunction = 'PiecewiseFunction'
clip2Display.OpacityArray = ['POINTS', 'VelocityP']
clip2Display.OpacityTransferFunction = 'PiecewiseFunction'
clip2Display.DataAxesGrid = 'GridAxesRepresentation'
clip2Display.SelectionCellLabelFontFile = ''
clip2Display.SelectionPointLabelFontFile = ''
clip2Display.PolarAxes = 'PolarAxesRepresentation'
clip2Display.ScalarOpacityUnitDistance = 0.23948920075608798
clip2Display.ScaleTransferFunction.Points = [-38.81049346923828, 0.0, 0.5, 0.0, 47.40387725830078, 1.0, 0.5, 0.0]
clip2Display.OpacityTransferFunction.Points = [-38.81049346923828, 0.0, 0.5, 0.0, 47.40387725830078, 1.0, 0.5, 0.0]
clip2Display.DataAxesGrid.XTitleFontFile = ''
clip2Display.DataAxesGrid.YTitleFontFile = ''
clip2Display.DataAxesGrid.ZTitleFontFile = ''
clip2Display.DataAxesGrid.XLabelFontFile = ''
clip2Display.DataAxesGrid.YLabelFontFile = ''
clip2Display.DataAxesGrid.ZLabelFontFile = ''
clip2Display.PolarAxes.PolarAxisTitleFontFile = ''
clip2Display.PolarAxes.PolarAxisLabelFontFile = ''
clip2Display.PolarAxes.LastRadialAxisTextFontFile = ''
clip2Display.PolarAxes.SecondaryRadialAxesTextFontFile = ''

Paraview-5.8.1 (wrong results):

clip1 = Clip(Input=groupDatasets1)
clip1.ClipType = 'Box'
clip1.HyperTreeGridClipper = 'Plane'
clip1.Scalars = [None, '']
clip1.ClipType.Position = [1e+299, 1e+299, 1e+299]
clip2 = Clip(Input=groupDatasets2)
clip2.ClipType = 'Box'
clip2.HyperTreeGridClipper = 'Plane'
clip2.Scalars = [None, '']
clip2.ClipType.Position = [1e+299, 1e+299, 1e+299]
clip2Display = Show(clip2, renderView1, 'UnstructuredGridRepresentation')
clip2Display.Representation = 'Surface'
clip2Display.ColorArrayName = [None, '']
clip2Display.OSPRayScaleFunction = 'PiecewiseFunction'
clip2Display.SelectOrientationVectors = 'None'
clip2Display.ScaleFactor = -2.0000000000000002e+298
clip2Display.SelectScaleArray = 'None'
clip2Display.GlyphType = 'Arrow'
clip2Display.GlyphTableIndexArray = 'None'
clip2Display.GaussianRadius = -1e+297
clip2Display.SetScaleArray = [None, '']
clip2Display.ScaleTransferFunction = 'PiecewiseFunction'
clip2Display.OpacityArray = [None, '']
clip2Display.OpacityTransferFunction = 'PiecewiseFunction'
clip2Display.DataAxesGrid = 'GridAxesRepresentation'
clip2Display.PolarAxes = 'PolarAxesRepresentation'
clip2Display.ExtractedBlockIndex = 2
clip2Display.OSPRayScaleFunction.Points = [0.0, 0.0, 0.5, 0.0, 21.0, 1.0, 0.5, 0.0]

Could you elaborate what the reason for these differences are?
Thank you very much for your support

Naeeme.dmo · September 22, 2020, 3:23pm

sorry, I forgot to post the result of the simple clip on the box.
Left: Paraview5.8.1 right: 5.5.0-RC3

mwestphal · September 23, 2020, 11:16am

I’m confused, can you try to reproduce your issue with a simple test, as I tried to do ?

Naeeme.dmo · September 23, 2020, 3:24pm

Sorry for the confusion.
So I ran this code on both versions of paraview (5.5.0 and 5.8.1):

paraview.compatibility.major = 5
paraview.compatibility.minor = 5

box = Box()

clip = Clip(Input=box, ClipType = 'Box')
clip.ClipType.Position= [0.0, 0.0, 0.0]
clip.ClipType.Bounds = [-1.,0.,-1.,1.,-1.,1.]

RenderView = GetActiveViewOrCreate('RenderView')
boxdisplay = GetDisplayProperties(clip, view=RenderView)

The code is supposed to make a zero centered unit cube and clip it on the yz axis.

The code works fine with paraview 5.5.0, I get the expected result, i.e half a box.

Whereas for paraview 5.8.1, the clip somehow cuts of a corner of the cube, which makes no sense to me, see the following screenshot

steps to reproduce

open paraview gui
click View > Python shell
paste the code in the Python shell
Press Enter

I am working on centos 8. I have paraview 5.5.0 (binaries) and paraview 5.8.1 (binaries). I load the different versions through a module management system.
Thanks for your help.

Naeeme.dmo · September 23, 2020, 5:47pm

I think there is a bug in backwards compatibility.
when I add the following line in the code, it works fine for paraview version 5.8.1:

 clip.ClipType.UseReferenceBounds = 1

So it seems like it has to be manually enabled. Unfortunately, this attribute does not exist in paraview-5.5.0. So I was not able to write a backward compatible script.

Observed behavior (Paraview 5.8.1)

Setting attribute ClipType.Bounds results in unexpected clip.

Expected behavior

Setting the attribute ClipType.Bounds automatically sets .UseReferenceBounds to true, which would result in a correct clip.

mwestphal · September 24, 2020, 12:44pm

FYI : @cory.quammen

mwestphal · September 28, 2020, 1:31pm

@Naeeme.dmo: You may want to open an issue : https://gitlab.kitware.com/paraview/paraview/-/issues

Naeeme.dmo · September 29, 2020, 11:37am

Ok, i did it:
https://gitlab.kitware.com/paraview/paraview/-/issues/20237