Platform: Windows 10
Houdini: 18.0.499

I used a Connectivity SOP set to Primitive connectivity type and Attribute set to “piece” to define the connected pieces of my geometry. The “piece” attribute ends up with a range of values from 0 to 2, which indicates three connected pieces of geometry. And when I hook up a Color SOP set to Random From Attribute “piece”, I see the three pieces of connected geometry in different colors.

However, when I connect a Measure SOP to this, set to Measure Area, Primitive Element Type, Accumulate By Piece, Piece Attribute “piece”, it creates four area values, not three. One of the three pieces is treated as two pieces and given two area measurements.

How can this happen, and how can I get the Measure SOP to only calculate and assign three area values?

Thanks.

(I've attached an example model that exhibits this phenomenon.)

Has anyone else been able to at least confirm the behavior I'm seeing (using the test geo I provided)?

your geometry is nonmanifold, so you can expect all kinds of problems

after you load you object you can try using Poly Doctor, set Primitives/Ill-Formed to Ignore and Topology/Non-Manifold to Repair, you can also check Visualize Repaired Points to see which area was causing the issue

then your Connectivity and Measure should work

you can still submit it as a bug for Measure SOP as in theory nonmanifold geo shouldn't trip area computation, especially not for poys

Thank you for the help! Much appreciated.