Minutes from 65th OpenVDB TSC meeting, Oct 13th, 2020, (EDT)

Attendees: *Nick* A., *Jeff* L., *Ken* M., *Dan* B.

Additional Attendees: Johannes Meng (Intel), JT Nelson (Blender),
Andre Pradhana (DW), Bruce Cherniak (Intel)

Regrets: *Peter* C.

Agenda:

1) Confirm quorum
2) Secretary
3) Forum
4) AX Follow-up
5) Filter Tile Support
6) Paged Array Segfault
7) USD Support
8) Next Meeting

1) Quorum was confirmed.

2) Secretary was Dan Bailey

3) Forum

One question on the forum about using Visual Studio and CMake. No-one in the TSC
has much experience in this area. Still might be useful to post that we don't
know the answer and encourage others in the community to comment. D&I group are
looking at how to improve onboarding. Many people who use OpenVDB through
Windows use vcpkg rather than compiling from source.

4) AX Follow-up

Nick to review all feedback. Will take a while to get through everything,
priority is the core library at the moment. SOP feedback will follow.

Int conversion is proving tricky. No JIT compilation based on the type in VEX.
In AX, there is a separate accessor per-type, so hard to resolve integer issues.
Most likely route forward is to introduce explicit integer types for bindings
and then in future turn these into an alias to make them all int. That would
avoid backwards compatibility issues.

Looking for alternatives to running over inactive values, however Nick relies on
this mechanism heavily. Jeff prefers the ability to provide an optional stencil
mask as an optimization.

Don't use VEX language editor, not only will it highlight syntax incorrectly,
but it will reference the VEX documentation. Currently no hooks to introduce a
custom language editor in Houdini. Easiest route is likely to incorporate this
into VDB then let SideFX introduce a new language editor when natively
integrating AX into Houdini.

5) Filter Tile Support

Nick has submitted a PR to add tile support to the filter methods. It eliminates
tile artefacts in smoothing.

6) Paged Array Segfault

Nick has reported a number of sporadic segfaults related to the PagedArray data
structure. Last instance of a segfault in PagedArray was fixed by switching from
vector to deque. May be related to a standard library implementation offering a
deque implementation that is not thread-safe. However, there does not appear to
be any pattern in compiler, standard library or platform.

Nick to provide Ken with a bit more data to help try and track down the root
problem.

7) USD Support

All agreed that it could use some work as the current VDB integration is fairly
basic.

8) Next Meeting

Next meeting is October 20th, 2020. 1pm-2pm EDT (GMT-4). Dan to present PR785
for discussion and review.
