3.5 KiB
Minutes from 55th OpenVDB TSC meeting, July 7th, 2020, (GMT)
Attendees: Nick A., Jeff L., Ken M., Dan B.
Additional Attendees: Bruce Cherniak (intel), Johannes Meng (Intel), Andre Pradhana (DW), JT Nelson (Blender), Peter Cheng (DW)
Regrets: Peter C.
Agenda:
-
Quorum was confirmed.
-
Secretary was Jeff Lait
-
Forum
Discussions about debug builds. There is advice on how to improve it, the changes are agreed upon, the question is who will do it. This is to fix multi-target cmake generators on Windows. The default version looks for debug variants, the downstream is supposed select. This is showing up because we finally have a working Windows build. We want to ensure we can still build debug symbols on Linux with an optimized build.
- CI Review
Now builds Houdini from actions cache. Seems to be mostly fine. One PR failed to download so populated an empty cache. Added a check to avoid this. When the download stops failing occasionally we can move from the Azure pipeline.
- Sharpen PR
Lots of stuff has changed. Dan tried to rebuild back at the point it was submitted, which also failed. So tried moving the branch, which was protected. So tried to close and repoen. But this re-did the CLA test so failed. So created a fresh clean PR for this. A few small changes but mostly getting it compiling.
This re-introduced a boost dependency for a multi-array reference on a flat array. We will have to remove this later.
There is now PR to work from. Ken to look at, skim the API, and add some unit tests.
- Fast Sweeping
Ken will go over the review comments today. Dan proposes that you can bucket the slices without sorting. A particular leaf node, for example, has 21 slices on the diagonal. So you don't need a list of indices to each slice. The current system has a hash to slices. Ken is unsure if the details will hold up. We should investigate this sooner after the PR is in.
Andrew Pearce is still proofing the PR from DW. Hopefully done by this week. What is the best way to create a mask grid from a Houdini grid? There is a boolean grid. If we use an SDF as a mask it would be confusing that the center isn't filled. We should copy the VDB tools::clip that uses topology.
Andre is an author on a paper with another approach than fast sweeping, Ken and him will investigate its applicability.
- 7.1
For 7.1, we will aim to have Fast Sweeping complete. Or, put another way, when fast sweeping is in we can release 7.1. We will not stress over vector support, and not add to the SOP. Instead it will be up to the tool to support it if it can.
- PR 747.
We seem to be using the wrong attribute name here. This is a bad merge from the Houdini side.
- Merging Trees together
Originally did level-by-level merge. Now is an operator you pass into a node manager. However, the node manager has a pre-cache so it can't modify during building, but has to keep rebuilding. Proposal to add a for-each top-down dynamic method that builds the cache at each level as you progress down. This means the node manager now has two modes - flat and static, or dynamic. OTOH, it always had a clear method. This is mostly a way to have a non pre-built constructor. Is a node manager a reference to a tree? Or is it just a set of leaf nodes? Maybe a dynamic node manager subclassing that does the auto rebuilding? We note a lot of operations already have to be careful of node managers, suggesting it is already a state machine.
Dan will create a PR and we will look at it.
- Next meeting
Tuesday July 14th 2020, 1pm EDT (GMT-4)