NanoVDB v32.7.0

[kmuseth]

Introducing NanoVDB v32.7.0, which is a major refactoring of v32.6, primarily related to the introduction of new namespaces and an accompanying restructuring of the directory layout of header files. This will likely require changes to client code! To this end I have included a shell script (cmd/updateFiles.sh) that will scan files and make (most) of the required changes.

The motivation for there these changes is twofold: First we want to use the same practice in terms of name spaces as OpenVDB and second the old version (32.6) was getting cluttered and messy. Specifically the main changes are:

1. Virtually everything in NanoVDB is no using nanovdb as a namespace
2. Additionally the following nested namespaces are introduced: math, tools, cuda, io
3. these namespaces are reflected in matching restructures in the directories of header files as well as names of functions, kernels and a classes.

Here are some examples of changes:

nanovdb::CpuTimer -> nanovdb::util::Timer
nanovdb::GpuTimer -> nanovdb::util::cuda::Timer
nanovdb::gridStats -> nanovdb::tools::gridStats
nanovdb::Coord -> nanovdb::math::Coord

[kmuseth]

@apradhana - so other than the fact that the CI is broken you're fine if I merge this into master?

[apradhana]

Hi, @kmuseth, yes, you can merge it to master. These are my reasons:

• As for the CI concerns: (1) I tested building and running the unit tests locally on my Linux and Windows machine, (2) I tested running your PR with a limited CI on my fork to see that the nanovdb-lite and Windows-dynamic CI were passing, (3) I'm working on top of the CI fixes that @Idclip has been working on (PR-1837) to fix the CI issues [see this PR]. As far as I can tell, the problems are not in your PR, but either in the CI runner or in CentOS 7.
• As far as this PR is concerned: the biggest change introduced in this PR is the major restructuring of the APIs to make it conform better with OpenVDB. You bumped the NanoVDB minor version for that and we added updateFiles.sh and updateFiles.py to aid developers make the necessary changes. That should cover all use cases. This also allows fVDB to use the NanoVDB version in the main repository, which should help us to discover any bug we may have missed.

One thing to note after this change is that we need to keep in mind that Util.h should always be at the bottom of the NanoVDB dependency tree, followed by Math.h, followed by NanoVDB.h.

[apradhana]

For completeness, I tested the NanoVDB version that comes from this PR along with the CI work that is currently in progress here and it shows that the failing CIs are the windows-static builds.

[Idclip]

Maybe fix the CI first if you're doing that anyway