Build: add WITH_OPENVDB_3_ABI_COMPATIBLE option.

Better fix for T54457. It seems Debian compiles OpenVDB without ABI 3
compatibility, while Arch does enable it as is the default in the OpeVDB
CMake build system.

So now there's an option that the distribution can set depending on how
they compile their OpenVDB package.

CMakeLists.txt

@@ -251,6 +251,8 @@ option(WITH_OPENSUBDIV    "Enable OpenSubdiv for surface subdivision" _init_OPEN
 
 option(WITH_OPENVDB       "Enable features relying on OpenVDB" OFF)
 option(WITH_OPENVDB_BLOSC "Enable blosc compression for OpenVDB, only enable if OpenVDB was built with blosc support" OFF)
+option(WITH_OPENVDB_3_ABI_COMPATIBLE "Assume OpenVDB library has been compiled with version 3 ABI compatibility" OFF)
+mark_as_advanced(WITH_OPENVDB_3_ABI_COMPATIBLE)
 
 # GHOST Windowing Library Options
 option(WITH_GHOST_DEBUG   "Enable debugging output for the GHOST library" OFF)

intern/openvdb/CMakeLists.txt

@@ -38,9 +38,14 @@ set(SRC
 if(WITH_OPENVDB)
 	add_definitions(
 		-DWITH_OPENVDB
-		-DOPENVDB_3_ABI_COMPATIBLE
 	)
 
+	if(WITH_OPENVDB_3_ABI_COMPATIBLE)
+		add_definitions(
+			-DOPENVDB_3_ABI_COMPATIBLE
+		)
+	endif()
+
 	list(APPEND INC_SYS
 		${BOOST_INCLUDE_DIR}
 		${TBB_INCLUDE_DIRS}

intern/openvdb/intern/openvdb_writer.cc

@@ -45,7 +45,7 @@ void OpenVDBWriter::insert(const openvdb::GridBase::Ptr &grid)
 
 void OpenVDBWriter::insert(const openvdb::GridBase &grid)
 {
-#if (OPENVDB_LIBRARY_MAJOR_VERSION_NUMBER >= 3)
+#if (OPENVDB_LIBRARY_MAJOR_VERSION_NUMBER <= 3) || defined(OPENVDB_3_ABI_COMPATIBLE)
 	m_grids->push_back(grid.copyGrid());
 #else
 	m_grids->push_back(grid.copyGridWithNewTree());