VTKHDF PartitionedDataSetCollection (PDC) file not working in Paraview

Support
1

I’m trying to create a VTKHDF file that has multiple blocks in it but I’ve not managed to do so yet. My initial question was here where I was pointed towards the documentation and given a working example file. Rather than re-opening that discussion I’m creating this as a new troubleshooting thread.

I’ve been testing things this morning but despite following the structure in the provided example from that thread, I cannot get my version to load in Paraview.

Here’s the example file that works:
test_composite.hdf (27.1 KB)

and here’s my test case with 4 random PolyData blocks:
hdf_multiblock_test.vtkhdf (2.4 MB)

When I try to open my version Paraview just immediately crashes without displaying any warnings, just closes. I can’t see anything immediately wrong like the missing Index that I previously had so I guess I must be doing something else incorrect.

I’m using Paraview 5.13 which I just installed last week and seems to be ok for everything else. I’m writing my files from a python code using h5py. Normal VTKHDF files written with h5py are displayed without issue.

2

Hello @jpmorr,

thanks for opening another thread, your data is almost correct you miss one last thing: the link creation order.

From the documentation : VTK File Formats - VTK documentation

The Assembly group and its children need to track creation order to be able to keep subtrees ordered. For this, you need to set H5G properties H5P_CRT_ORDER_TRACKED and H5P_CRT_ORDER_INDEXED on each group when writing the Assembly.

if you check your data you’ll see that you miss for VTKHDF, Assembly and Assembly’s subgroups this tag:

image
image968×281 36.7 KB

With h5py, when creating a new group you can enforce this tag like this:

import h5py as h5

f = h5.File('your_data.vtkhdf', 'w')

# VTKHDF, Assembly need to be tagged with the track_order
root = f.create_group('VTKHDF', track_order=True)
assembly = root.create_group('Assembly', track_order=True)
3

@lgivord Thanks for checking this. I thought it might be something like that but I’m now a little confused. In the test file that works, the creation order is not tracked, as you can see from the screenshot below.

image
image1146×1032 28.6 KB

I’m going to try re-writing my files with the creation order tracked (will report back shortly). In this case, I presume the Index needs to match the creation order?

4

@lgivord Thanks for solving this.

My main problem was that I was not tracking the order for the root as in your code:
root = f.create_group('VTKHDF', track_order=True) but I was also attempting to track creation order for the block data which may have been the cause.

I also see the difference between Attribute creation order and Link creation order now.

Everything seems to be working well now.

2 Likes