Merge pull request AcademySoftwareFoundation#1232 from apradhana/Fix_…

…Building_NanoVDB_From_Root_Without_OpenVDB

Fix installing nanovdb from the root openvdb build directory.

CMakeLists.txt

@@ -552,8 +552,19 @@ if(USE_STATIC_DEPENDENCIES)
 endif()
 
 # Configure OpenVDB Library and ABI versions
+set(NEEDS_OPENVDB OFF)
+
+if(OPENVDB_BUILD_AX OR
+   OPENVDB_BUILD_BINARIES OR
+   OPENVDB_BUILD_UNITTESTS OR
+   OPENVDB_BUILD_HOUDINI_PLUGIN OR
+   OPENVDB_BUILD_MAYA_PLUGIN OR
+   OPENVDB_BUILD_PYTHON_MODULE OR
+   OPENVDB_BUILD_HOUDINI_ABITESTS)
+  set(NEEDS_OPENVDB ON)
+endif()
 
-if(NOT OPENVDB_BUILD_CORE)
+if(NOT OPENVDB_BUILD_CORE AND NEEDS_OPENVDB)
   # Find VDB installation and determine lib/abi versions. This resets the
   # version and ABI numbers
   find_package(OpenVDB REQUIRED)

README.md

@@ -101,3 +101,49 @@ cd build
 cmake -DCMAKE_TOOLCHAIN_FILE=<PATH_TO_VCPKG>\scripts\buildsystems\vcpkg.cmake -DVCPKG_TARGET_TRIPLET=x64-windows -A x64 ..
 cmake --build . --parallel 4 --config Release --target install
 ```
+
+#### Building NanoVDB
+
+**First example: building NanoVDB and OpenVDB core**
+
+NanoVDB is now a module of the larger OpenVDB project. A user can build both libraries together. This will build the OpenVDB core library, install the NanoVDB header files, and build the NanoVDB command-line tools in the `build/nanovdb/cmd` directory. From the 'root' OpenVDB project directory (change the dependency paths to match your environment):
+  ```console
+  foo@bar:~$ mkdir build
+  foo@bar:~$ cd build
+  foo@bar:~$ cmake .. -DUSE_NANOVDB=ON -DTBB_ROOT=/path/to/tbb -DBOOST_ROOT=/path/to/boost -DBLOSC_ROOT=/path/to/blosc -DCMAKE_INSTALL_PREFIX=/install/path
+  foo@bar:~$ make -j 4 && make install
+  ```
+Note that the default value of `NANOVDB_USE_OPENVDB` is linked to `OPENVDB_BUILD_CORE` option and can be overriden by passing on `-DNANOVDB_USE_OPENVDB=OFF`. The `Boost` library is included because it is a requirement for building OpenVDB.
+
+In general, CMake will try to find every optional dependency when a user opts to add an additional dependency. Be sure to check the CMake log to see what dependencies were **not** found.
+
+**Second example: NanoVDB with no dependencies**
+
+From the 'root' OpenVDB project directory:
+  ```console
+  foo@bar:~$ mkdir build
+  foo@bar:~$ cd build
+  foo@bar:~$ cmake .. -DUSE_NANOVDB=ON -DOPENVDB_BUILD_CORE=OFF -DOPENVDB_BUILD_BINARIES=OFF -DNANOVDB_USE_TBB=OFF -DNANOVDB_USE_BLOSC=OFF -DNANOVDB_USE_ZLIB=OFF -DCMAKE_INSTALL_PREFIX=/install/path
+  foo@bar:~$ make -j 4 && make install
+  ```
+
+Another option is to build it from the NanoVDB directory itself, which is much simpler:
+  ```console
+  foo@bar:~$ cd nanovdb/nanovdb
+  foo@bar:~$ mkdir build
+  foo@bar:~$ cd build
+  foo@bar:~$ cmake .. -DCMAKE_INSTALL_PREFIX=/install/path
+  foo@bar:~$ make -j 4 && make install
+  ```
+Both options will install the NanoVDB header files to the `/install/path` as well as building `nanovdb_print` and `nanovdb_validate` executable. The path where these executables are installed will be different: in the first option they will be under `build/nanovdb/cmd` directory; whilst in the second option they will be under the `build/cmd/` directory.
+
+**Third example: build 'everything' in NanoVDB along with OpenVDB core**
+
+From the root OpenVDB directory:
+  ```console
+  foo@bar:~$ mkdir build
+  foo@bar:~$ cd build
+  foo@bar:~$ cmake .. -DUSE_NANOVDB=ON -DNANOVDB_BUILD_UNITTESTS=ON -DNANOVDB_BUILD_EXAMPLES=ON -DNANOVDB_BUILD_BENCHMARK=ON -DNANOVDB_USE_INTRINSICS=ON -DNANOVDB_USE_CUDA=ON -DNANOVDB_CUDA_KEEP_PTX=ON -DTBB_ROOT=/path/to/tbb -DBOOST_ROOT=/path/to/boost -DBLOSC_ROOT=/path/to/blosc -DGTEST_ROOT=/path/to/gtest -DCMAKE_INSTALL_PREFIX=/install/path
+  foo@bar:~$ make -j 4 && make install
+  ```
+Note that if you already have the correct version of OpenVDB pre-installed, you can configure CMake to link against that library by passing the arguments `-DOPENVDB_BUILD_CORE=OFF -DOPENVDB_BUILD_BINARIES=OFF -DOPENVDB_ROOT=/path/to/openvdb` when invoking `cmake`.

doc/nanovdb/HowToBuild.md

@@ -25,15 +25,23 @@ In general, CMake will try to find every optional dependency when a user opts to
 
 ## Second example: NanoVDB with no dependencies
 
-The simplest way is to build it from the NanoVDB directory itself:
+From the 'root' OpenVDB project directory:
+  ```console
+  foo@bar:~$ mkdir build
+  foo@bar:~$ cd build
+  foo@bar:~$ cmake .. -DUSE_NANOVDB=ON -DOPENVDB_BUILD_CORE=OFF -DOPENVDB_BUILD_BINARIES=OFF -DNANOVDB_USE_TBB=OFF -DNANOVDB_USE_BLOSC=OFF -DNANOVDB_USE_ZLIB=OFF -DCMAKE_INSTALL_PREFIX=/install/path
+  foo@bar:~$ make -j 4 && make install
+  ```
+
+Another option is to build it from the NanoVDB directory itself, which is much simpler:
   ```console
   foo@bar:~$ cd nanovdb/nanovdb
   foo@bar:~$ mkdir build
   foo@bar:~$ cd build
   foo@bar:~$ cmake .. -DCMAKE_INSTALL_PREFIX=/install/path
   foo@bar:~$ make -j 4 && make install
   ```
-This will install the NanoVDB header files to the `/install/path` as well as building `nanovdb_print` and `nanovdb_validate` executable.
+Both options will install the NanoVDB header files to the `/install/path` as well as building `nanovdb_print` and `nanovdb_validate` executable. The path where these executables are installed will be different: in the first option they will be under `build/nanovdb/cmd` directory; whilst in the second option they will be under the `build/cmd/` directory.
 
 ## Third example: build 'everything' in NanoVDB along with OpenVDB core
 
@@ -44,4 +52,4 @@ From the root OpenVDB directory:
   foo@bar:~$ cmake .. -DUSE_NANOVDB=ON -DNANOVDB_BUILD_UNITTESTS=ON -DNANOVDB_BUILD_EXAMPLES=ON -DNANOVDB_BUILD_BENCHMARK=ON -DNANOVDB_USE_INTRINSICS=ON -DNANOVDB_USE_CUDA=ON -DNANOVDB_CUDA_KEEP_PTX=ON -DTBB_ROOT=/path/to/tbb -DBOOST_ROOT=/path/to/boost -DBLOSC_ROOT=/path/to/blosc -DGTEST_ROOT=/path/to/gtest -DCMAKE_INSTALL_PREFIX=/install/path
   foo@bar:~$ make -j 4 && make install
   ```
-Note that if you already have the correct version of OpenVDB pre-installed, you can configure CMake to link against that library by passing the arguments `-DOPENVDB_BUILD_CORE=OFF -DOPENVDB_BUILD_UNITTESTS=OFF -DOPENVDB_ROOT=/path/to/openvdb` when invoking `cmake`.
+Note that if you already have the correct version of OpenVDB pre-installed, you can configure CMake to link against that library by passing the arguments `-DOPENVDB_BUILD_CORE=OFF -DOPENVDB_BUILD_BINARIES=OFF -DOPENVDB_ROOT=/path/to/openvdb` when invoking `cmake`.