Improvements to NanoVDB by kmuseth · Pull Request #2108 · AcademySoftwareFoundation/openvdb

kmuseth · 2025-10-14T05:01:51Z

Major rewrite of nanovdb::NanoToOpenVDB, which now allows nanovdb::IndexGrids and blind (or side-car) data to be converted into an openvdb grid.
Added stand-alone function nanovd::writeUncompressedGrid that allows nanovdb::IndexGrids and blind (or side-car) data to be written directly to a stream.
Extended nanovdb::GridBlindDataSemantic with nanovdb::GridClass types to support conversion between IndexGrids and regular grids.
nanovdb_print now (optionally) prints the blind data count per grid.
Removed nanovdb::ValueIndexMask and nanovdb::ValueOnIndexMask since they are no longer used by fVDB (or elsewhere).
NanoVDB version is now 32.9.0, so the ABI of the grid is preserved but not the API. However, the API changes are very minor!

Signed-off-by: Ken Museth <ken.museth@gmail.com>

Signed-off-by: Ken <ken.museth@gmail.com>

Signed-off-by: Ken Museth <ken.museth@gmail.com>

Signed-off-by: Ken <ken.museth@gmail.com>

Signed-off-by: Ken Museth <ken.museth@gmail.com>

Signed-off-by: Ken <ken.museth@gmail.com>

matthewdcong · 2025-10-19T20:05:34Z

+- Added Mat classes and other math types to NanoVDB
+- Improvements to mGPU grid building and introduction of a separate test executable for mGPU tests
+- Major rewrite of nanovdb::NanoToOpenVDB, which now allows nanovdb::IndexGrids and blind (or side-car) data to be converted into an openvdb grid.
+- Added stand-alone function nanovd::writeUncompressedGrid that allows nanovdb::IndexGrids and blind (or side-car) data to be written directly to a stream.


matthewdcong · 2025-10-19T20:08:27Z

+
+    if constexpr(!BuildTraits<NanoBuildT>::is_special) {
+        const auto* src = trait::mapPtr(srcLeaf->data()->mValues);// doesn't work for compressed data, bool or ValueMask
+        for (auto *dst = dstLeaf->buffer().data(), *end = dst + 512; dst != end; dst += 4, src += 4) {


Is this loop needed? It seems like this could be a memcpy or std::copy.

looking at the documentation for std::copy it looks like it performs a pretty naive for-loop without loop-un-rolling. So, I'm convinced it will actually outperform my code ...

switched to std::copy but kept the old implementation just in case it was in fact faster

matthewdcong · 2025-10-19T20:09:10Z

+    if constexpr(!BuildTraits<NanoValueT>::is_special) {
+        if constexpr(util::is_same_v<NanoIndexT, ValueIndex>) {
+            const auto* src = trait::mapPtr(sideCar + srcLeaf->data()->mOffset);
+            for (auto *dst = dstLeaf->buffer().data(), *end = dst + 512; dst != end; dst += 4, src += 4) {


same as above

Signed-off-by: Ken <ken.museth@gmail.com>

Signed-off-by: Andrew Reidmeyer <areidmeyer@nvidia.com>

…xmask

Signed-off-by: Ken Museth <ken.museth@gmail.com>

matthewdcong

Looks good, thanks for the changes.

Signed-off-by: Ken <ken.museth@gmail.com>

sifakis

Looks great, just minor and highly optional comments

sifakis · 2025-10-21T18:21:45Z

+Improvements:
+- Added nanovdb/tools/cuda/DilateGrid.cuh, which performs topology dilation on the GPU.
+- Added nanovdb/tools/cuda/MergeGrids.cuh, which merges the topology of two grids on the GPU.
+- Added nanovdb/tools/cuda/CoarsenGrid.cuh, which performs topological coarsening of grids on the GPU.


(Optional) Additional features to mention, if useful:

Added nanovdb/tools/cuda/PruneGrid.cuh which prunes the topology of a grid using a sidecar mask on the GPU.

Added nanovdb/util/cuda/Injection.cuh which facilitates sidecar data copying - on the GPU - in the overlap of two grids with different topology.

sifakis · 2025-10-21T20:50:57Z

+        } else {
+            const auto* src = trait::mapPtr(sideCar);
+            auto *dst = dstLeaf->buffer().data();
+            for (int i = 0; i < 512; i += 4) {


Somewhat related to @matthewdcong 's comment above ... a possible optimization might be

auto offset = srcLeaf->firstOffset(); for (int w = 0; w < 8; ++w) { auto word = srcLeaf->valueMask().words()[w]; for (int bit = 0; bit < 64; ++bit, word >>= 1) *dst++ = src[(word&0x1UL)?offset++:0]; }

in order to avoid calls to popCnt; although those might vectorize on AVX512.
At any rate, this is not essential as leaf node allocation is likely the key contributor to runtime in this tool

Signed-off-by: Ken <ken.museth@gmail.com>

sifakis

Looks good to me!

Signed-off-by: Ken <ken.museth@gmail.com>

apradhana · 2025-10-23T00:48:57Z

+- Major rewrite of nanovdb::NanoToOpenVDB, which now allows nanovdb::IndexGrids and blind (or sidecar) data to be converted into an openvdb grid.
+
+Improvements:
+- Improvements to mGPU grid building and introduction of a separate test executable for mGPU tests


(Optional). Consider mentioning:

Added support for LevelSet, FogVolume, and Staggered grid semantic. Added toGridClass and toSemantic to map Grid Blind data semantic to Grid class and vice versa.

apradhana

One nitpick comment regarding the Change Notes. Looks good to me!

Signed-off-by: Ken <ken.museth@gmail.com>

major improvements to NanoToOpenVDB

4033830

Signed-off-by: Ken Museth <ken.museth@gmail.com>

kmuseth requested review from Idclip, apradhana, danrbailey, jmlait and richhones as code owners October 14, 2025 05:01

kmuseth added 10 commits October 14, 2025 09:54

fixed CI issues

6ded13c

Signed-off-by: Ken <ken.museth@gmail.com>

fixed issues in GridBlindMetaData::isValid

4d09cc4

Signed-off-by: Ken Museth <ken.museth@gmail.com>

added improvements to nanovdb_print

ecace3a

Signed-off-by: Ken Museth <ken.museth@gmail.com>

Merge remote-tracking branch 'origin/master' into GridIndex_to_OpenVDB

dc39f07

improved change notes

b7c5a67

Signed-off-by: Ken Museth <ken.museth@gmail.com>

fixed build issues

9fa2e95

Signed-off-by: Ken Museth <ken.museth@gmail.com>

fixed compiler warning on Windows

d992d50

Signed-off-by: Ken Museth <ken.museth@gmail.com>

fixed compiler warning on Windows

3394708

Signed-off-by: Ken Museth <ken.museth@gmail.com>

fixed compiler warning on Windows

dc4ff93

Signed-off-by: Ken Museth <ken.museth@gmail.com>

fixed compiler warning on Windows

fbf715a

Signed-off-by: Ken Museth <ken.museth@gmail.com>

swahtz mentioned this pull request Oct 16, 2025

Switch NanoVDB tests to using macos 14 runners #2111

Merged

kmuseth added 13 commits October 16, 2025 10:40

Merge remote-tracking branch 'upstream/master' into GridIndex_to_OpenVDB

1ccece9

changes to examples

f03e90e

Signed-off-by: Ken <ken.museth@gmail.com>

improved API in NanoToOpenVDB

699e0e8

Signed-off-by: Ken <ken.museth@gmail.com>

trying a fix for Windows

88df235

Signed-off-by: Ken <ken.museth@gmail.com>

replaced std::emable_if with util::enable_if

ff49dff

Signed-off-by: Ken <ken.museth@gmail.com>

snapshot

cb9965f

Signed-off-by: Ken <ken.museth@gmail.com>

added nanovdb::util::enable_if_t and simplified code

8517a5b

Signed-off-by: Ken <ken.museth@gmail.com>

cleanup

4033ce2

Signed-off-by: Ken Museth <ken.museth@gmail.com>

major cleanup

1e1752a

Signed-off-by: Ken <ken.museth@gmail.com>

removed whitespace

e2860dd

Signed-off-by: Ken <ken.museth@gmail.com>

minor improvements and new patch version number

397b66d

Signed-off-by: Ken <ken.museth@gmail.com>

removed nanovdb::ValueIndexMask and nanovdb::ValueOnIndexMask

028792d

Signed-off-by: Ken <ken.museth@gmail.com>

removed ValueIndexMask in python module

2ca8e8b

Signed-off-by: Ken <ken.museth@gmail.com>

matthewdcong reviewed Oct 19, 2025

View reviewed changes

kmuseth and others added 4 commits October 19, 2025 15:01

addressed review comments

bc4068c

Signed-off-by: Ken <ken.museth@gmail.com>

PNanoVDB remove indexmask grid types.

eb1a8be

Signed-off-by: Andrew Reidmeyer <areidmeyer@nvidia.com>

Merge pull request #6 from areidmeyer/areidmeyer/pnanovdb_remove_inde…

26f2b1a

…xmask

fixed spelling

984fda4

Signed-off-by: Ken Museth <ken.museth@gmail.com>

kmuseth added the ax label Oct 20, 2025

kmuseth changed the title ~~major improvements to NanoToOpenVDB~~ Improvements to NanoVDB Oct 20, 2025

kmuseth requested a review from matthewdcong October 20, 2025 18:47

matthewdcong approved these changes Oct 20, 2025

View reviewed changes

kmuseth added 2 commits October 21, 2025 11:07

Merge remote-tracking branch 'upstream/master' into GridIndex_to_OpenVDB

a3a3dff

updated change notes

ea6e8ee

Signed-off-by: Ken <ken.museth@gmail.com>

danrbailey mentioned this pull request Oct 21, 2025

Fix minor spelling issues in Convex tools #2112

Merged

sifakis reviewed Oct 21, 2025

View reviewed changes

kmuseth added 4 commits October 21, 2025 20:19

Merge remote-tracking branch 'upstream/master' into GridIndex_to_OpenVDB

c1fb6bb

Merge remote-tracking branch 'upstream/master' into GridIndex_to_OpenVDB

898ca1d

improved documentation

f2a4b92

Signed-off-by: Ken <ken.museth@gmail.com>

removed whitespace

c79c869

Signed-off-by: Ken <ken.museth@gmail.com>

sifakis approved these changes Oct 22, 2025

View reviewed changes

improved pending changes

10ac740

Signed-off-by: Ken <ken.museth@gmail.com>

apradhana reviewed Oct 23, 2025

View reviewed changes

apradhana approved these changes Oct 23, 2025

View reviewed changes

addressed review comment

9ee6928

Signed-off-by: Ken <ken.museth@gmail.com>

kmuseth merged commit a273ab3 into AcademySoftwareFoundation:master Oct 23, 2025
14 checks passed

kmuseth deleted the GridIndex_to_OpenVDB branch October 23, 2025 02:56

tetov mentioned this pull request Nov 4, 2025

[BUILD] [NanoVDB] PyIO.cc:42:47: error: 'padding' is not a member of 'nanovdb::io::FileMetaData' #2134

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kmuseth commented Oct 14, 2025 •

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