Optionally include CUDA DLLs in open3d-package

CHANGELOG.md

@@ -1,4 +1,5 @@
 ## Main
+-   Allow bundling CUDA-DLLs into the pip-package on Windows with BUNDLE_CUDA_SHARED_LIBS.
 -   Corrected documentation for Link Open3D in C++ projects (broken links).
 -   Fix DLLs not being found in Python-package. Also prevent PATH from being searched for DLLs, except CUDA (PR #7108)
 -   Fix MSAA sample count not being copied when FilamentView is copied

CMakeLists.txt

@@ -146,6 +146,7 @@ option(BUILD_AZURE_KINECT         "Build support for Azure Kinect sensor"    OFF
 option(BUILD_TENSORFLOW_OPS       "Build ops for TensorFlow"                 OFF)
 option(BUILD_PYTORCH_OPS          "Build ops for PyTorch"                    OFF)
 option(BUNDLE_OPEN3D_ML           "Includes the Open3D-ML repo in the wheel" OFF)
+option(BUNDLE_CUDA_SHARED_LIBS    "Includes CUDA-DLLs in the wheel (win only)" OFF)
 
 # Release build options
 option(DEVELOPER_BUILD      "Add +commit_hash to the project version number" ON )

cpp/pybind/CMakeLists.txt

@@ -127,6 +127,15 @@ install_name_tool -change $libomp_library @rpath/$(basename $libomp_library) \
         COMMAND bash update_pybind_libomp.sh
         COMMENT "Updating pybind to use packaged libomp")
 endif()
+if (WIN32 AND BUILD_CUDA_MODULE AND BUNDLE_CUDA_SHARED_LIBS)
+	# Just bundle all DLLs from CUDA to avoid having to update
+	# an explicit listing of required DLLs.
+	# Only bundling required DLLs would decrease the package size,
+	# but not by much, as cublas, cusparse and cusolver alone
+	# need about 1GB.
+	file(GLOB CUDA_DLLS "${CUDAToolkit_BIN_DIR}/*.dll")
+	list(APPEND PYTHON_EXTRA_LIBRARIES ${CUDA_DLLS})
+endif()
 
 # Use `make python-package` to create the python package in the build directory
 # The python package will be created at PYTHON_PACKAGE_DST_DIR. It contains:

python/open3d/__init__.py

@@ -44,10 +44,12 @@
             ImportWarning,
         )
     try:
-        if sys.platform == "win32" and sys.version_info >= (3, 8):
+        if sys.platform == "win32" and sys.version_info >= (3, 8) and not _build_config["BUNDLE_CUDA_SHARED_LIBS"]:
             # Since Python 3.8, the PATH environment variable is not used to find DLLs anymore.
             # To allow Windows users to use Open3D with CUDA without running into dependency-problems,
             # look for the CUDA bin directory in PATH and explicitly add it to the DLL search path.
+            # Only do this if the CUDA shared libraries are not bundled with Open3D to prevent conflicts
+            # beteween bundled and system libraries.
             cuda_bin_path = None
             for path in os.environ['PATH'].split(';'):
                 # search heuristic: look for a path containing "cuda" and "bin" in this order.