Threshold of Vertex Data

ParaView Support
1

I have a PolyVertex dataset that has an integer as a value on each vertex. For a simplified test case, here is a file that demonstrates my issue:

# vtk DataFile Version 1.0
Cube example
ASCII

DATASET POLYDATA
POINTS 8 float
0.0 0.0 0.0
1.0 0.0 0.0
1.0 1.0 0.0
0.0 1.0 0.0
0.0 0.0 1.0
1.0 0.0 1.0
1.0 1.0 1.0
0.0 1.0 1.0
POLYGONS 6 30
4 0 1 2 3
4 4 5 6 7
4 0 1 5 4
4 2 3 7 6
4 0 4 7 3
4 1 2 6 5

POINT_DATA 8
SCALARS my_scalars int
LOOKUP_TABLE custom_table
1
1
1
1
2
2
3
3
LOOKUP_TABLE custom_table 8
0.0 0.0 0.0 1.0
1.0 0.0 0.0 1.0
0.0 1.0 0.0 1.0
1.0 1.0 0.0 1.0
0.0 0.0 1.0 1.0
1.0 0.0 1.0 1.0
0.0 1.0 1.0 1.0
1.0 1.0 1.0 1.0

I load this into ParaView and see the data. I can hover over the vertices and see the correct values. All is well and good. I apply the “Threshold” filter (via the toolbar button) and select the “my_scalars” and select 3 as the lower and upper bound. Click the apply button. nothing shows up in ParaView. I would have thought that I would have seen 2 vertices showing. I have the vertex size cranked up to 20 and I use “Points” as my representation. If I use 2 as the lower and 3 as the upper I will now see 4 points. So my question is: Why when I use 3 as my upper and lower bound for the threshold do I not see any vertices at all? This is with version 5.10.1 on macOS and Windows.

Thanks
Mike Jackson

2

Hello @Michael_Jackson

the threshold filter extract cells, not vertices. If you use value “1” you’ll get a face of your cube extracted because all points of the first face are in the range [1;1].

In order to filter vertices with the threshold filter, you should convert your points to vertex cells.

Alternatively you can use the Find Data dialog to query points based on their attribute values.

Best,
François