Minutes from 101st OpenVDB TSC meeting, Aug 3rd, 2021, (EDT)

Attendees: *Ken* M., *Nick* A., *Dan* B., *Andre* P.

Additional Attendees: Richard Jones (DNEG), J. T. Nelson (Blender),
Bruce Cherniak (Intel)

Regrets: *Jeff* L.

1) Confirm quorum
2) Secretary
3) Distributed Workflow in OpenVDB
4) OpenVDB 9.0 release date
5) OpenEXR 3
6) NanoVDB
7) Open Source Day 2021
8) Next meeting

1) Confirm quorum

Quorum is present.

2) Secretary

Secretary was Andre Pradhana.

3) Distributed Workflow in OpenVDB 

Since Andre brought up his intention to put in work in the
GAS_NetSliceVDBExchange DOP node, Ken brought up the topic of OpenVDB's support
for distributed computation workflow.

DNEG has an implementation of distributed simulation using OpenVDB.
According to Nick, the implementation of distributed sim at DNEG uses MPI.
Dan thinks that we need to loop Jeff Lait into the conversation because SideFX's
implementation depends on TCP/IP protocol. Ken thinks that we need to have a wrapper
for the communication protocal and have a default implementation that is based
on MPI. Nick thinks that it is a big scale project.

Dan thinks that it is useful to have a high-level simulation example that uses
OpenVDB where we can demonstrate that the distributed framework works.

Ken thinks that if we can agree on having an API for distributed communication,
then we can start there, e.g. to have  a wrapper for a communication manager and
to have a tool here is a way to exchange data in halo regions. Then we can support
more tools.

Nick was working on an approval from DNEG to get their implementation to be
open-sourced. Richard Jones will try to follow up with DNEG on whether they can
open source the distributed code.

4) OpenVDB 9.0 relese date

VFX Reference Platform agrees with the release of OpenVDB 9.0 by November 1st 2021.

5) OpenEXR 3

OpenVDB has not updated our version of OpenEXR 3. Unless we update our OpenEXR
dependency to OpenEXR 3, they need to revert back the OpenEXR version in the VFX
Reference Platform to version 2.5. Dan and Nick think that we need to get this
done for OpenVDB 9.0. We need to upgrade our embedded half into the one that comes
from OpenEXR 3.0. We need to do this in a backward-compatible way. JT says that
the OpenEXR team will no longer spend time on the 2.x versions.

Dan says that he will communicate with OpenEXR people that we want
their help to upgrade OpenVDB's compatibility with OpenEXR 3.0. If
no one has completed this task by October, then Dan will do this
task.

6) NanoVDB

Ken created a PR for nanovdb.Remove nanovdb viewer for now. This is PR-1139.

7) Open Source Day 2021

Dan wants to continue to move some functionalities from tree to tools.
Dan wants to look into the instantiation compile time. Dan wants to
continue working on fast VDB points merging.

Nick can talk on OpenVDB AX. Nick will talk about point-statistics and
rasterization PR. What about the distribution support? Ken will talk about
the read-only out-of-core grid. Ken will also talk about the sharpening PR
from Peter Cucka. On a side note, this PR is blocked because of dependency
on boost::multi_array.

We also talk about highlights from the change logs. Ken and JT think that
we can improve on recording the highlights on the change logs. Some
highlights include:
 - Releases: 7.1, 7.2, 8.0, 8.1.
 - Morphology improvement: erode and dilate performance improvement and also
adding 18 and 26 neighbors support on erotion.
 - OpenVDB AX is added to the repository.
 - We reduce some boost dependencies.
 - Significant improvement on volume on AX.
 - Added support for tiles in tools, such as filter.
 - Better Windows support.
 - Make OpenEXR dependency to be optional for the core library.
 - Added Fast Sweeping tools.
 - Houdini SOPs: VDB Merge (new), Extrapolate (new), Activate (faster),
   Smooth (tile support).

We will start with high-lights and then roadmap. We will continue talking
about this through emails.

8) Next meeting

Next meeting is August 17th, 2021. 12pm-1pm EST (GMT-5).
