Merge pull request #1514 from danrbailey/notes_18_10

Add meeting notes for 18 Oct

tsc/meetings/2022-10-18.md

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+Minutes from 151st OpenVDB TSC meeting, October 18th, 2022
+
+Attendees: *Jeff* L., *Andre* P, *Dan* B., *Rich* J., *Ken* M., *Nick* A.
+
+Additional Attendees: Greg Hurst (United Therapeutics), Sebastian Gaida, Barry Dempsey
+
+Agenda:
+
+1) Confirm quorum
+2) Secretary
+3) VDB Mathematica Link
+4) AX
+5) Houdini LZMA
+6) ValueAccessor Performance Improvements
+7) CMake VDB Tool
+8) Next Release
+9) Next meeting
+
+------------
+
+1) Confirm quorum
+
+Quorum is present.
+
+2) Secretary
+
+Secretary is Dan Bailey.
+
+3) VDB Mathematica Link
+
+Almost ready for this PR to be merged. Documentation still to be finialized. This plugin will not be
+built through CI, still waiting for progress there. Question about licensing. One of the 3rd party
+dependencies is LTemplate which uses a different license to VDB. MIT License is compatible and does
+not do copy left so no further action needed.
+
+4) AX
+
+Nick has looked at LLVM 15, but significant work is needed to support this so this version will
+explicitly not be supported in VDB 10.0.
+
+Weekly CI is still failing with a Blosc 1.17 error, if all checks are green seems that we can
+disable this error now.
+
+In LLVM 14, a new FMA option which was previously off by default has now been enabled. This is done
+at the IR level so will be hard to work around. This is exposed using the fpcontract compiler
+flag.
+
+5) Houdini LZMA
+
+Jeff has looked into the LZMA issue in Houdini and confirms the problem that CentOS7 now uses a
+different patch version of LZMA to the one that Houdini ships with as a result of the dependency on
+boost::iostreams. There are some options, including to extend the LZMA shipped with Houdini to
+include the new symbols from the updated CentOS7 version. This issue will go away as users
+transition away from CentOS7.
+
+For the CI where this is a problem, we can circumvent this issue by disabling delayed loading which
+means boost::iostreams is not used. This is the route we will go for the VDB 10 release to switch
+back on the Houdini plugin builds.
+
+6) ValueAccessor Performance Improvements
+
+In addition to the performance improvements, this PR fixes a couple of bugs with adding leaf nodes
+through the ValueAccessor. Jeff highlights that some of these changes were proposed in PR1282. Nick
+to look over this PR and compare his implementation. One component included in this old PR which is
+not present in the new one is the change to fix for adding tiles through the ValueAccessor.
+
+7) CMake VDB Tool
+
+The CMake build for the vdb_tool uses inconsistent names for the CMake variables and does not use
+targets for compile options and definitions which risks creating confusing behavior when switching
+on this tool as these options will apply to all the subsequent components. Andre to look into
+addressing both of these issues before VDB10.
+
+8) Next Release
+
+Continue to look at resolving all the Weekly CI issues and the VDB10 release will be started next
+week.
+
+There is a hesitancy to do more frequent releases because the release process is perceived to be
+slow. This is something the TSC should re-evaluate based on the ease of doing the VDB10 release.
+Only two releases in the 9.x series. Ideally, the next minor release should follow in under six
+months.
+
+Dan commits to look at the PointReplicate PR soon after the VDB 10 release.
+
+9) Next meeting
+
+Next meeting is on October 25th, 2022. 2pm-3pm EDT (GMT-4).