cmake: fix Windows Houdini build — auto-detect openvdb_sesi and set search paths

On Windows, Houdini ships its OpenVDB library as openvdb_sesi.lib/dll
rather than openvdb.lib/dll (the name used on Linux/macOS). FindOpenVDB
searches only for the component name verbatim, so Windows Houdini builds
have always required the manual cmake flag:

  -DOpenVDB_openvdb_LIBRARY=<HFS>/custom/houdini/dsolib/openvdb_sesi.lib

Fix this by adding an OpenVDB section to OpenVDBHoudiniSetup.cmake that:
  - Sets OPENVDB_LIBRARYDIR/OPENVDB_INCLUDEDIR to Houdini's toolkit paths
    so FindOpenVDB knows where to look without extra hints.
  - On Windows, pre-sets OpenVDB_openvdb_LIBRARY by searching for both
    openvdb_sesi and openvdb names in Houdini's dsolib directory,
    eliminating the need for a manual command-line override.

Tested with Houdini 20.5.613 (OpenVDB 11.0.0, ABI 11) on Windows 11.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Signed-off-by: KAMAL <m.kamalvfx@gmail.com>

Author: KamalTD

cmake/OpenVDBHoudiniSetup.cmake

@@ -317,6 +317,27 @@ elseif(WIN32)
   list(APPEND CMAKE_FIND_LIBRARY_SUFFIXES "_sidefx.lib")
 endif()
 
+# OpenVDB - point FindOpenVDB at Houdini's installation
+
+if(NOT OPENVDB_LIBRARYDIR)
+  set(OPENVDB_LIBRARYDIR ${HOUDINI_LIB_DIR})
+endif()
+if(NOT OPENVDB_INCLUDEDIR)
+  set(OPENVDB_INCLUDEDIR ${HOUDINI_INCLUDE_DIR})
+endif()
+
+# On Windows, Houdini ships its OpenVDB library as openvdb_sesi.lib/dll
+# rather than openvdb.lib/dll. FindOpenVDB only searches for the component
+# name verbatim, so pre-set the cache variable here so it resolves correctly
+# without requiring -DOpenVDB_openvdb_LIBRARY on the command line.
+if(WIN32 AND NOT OpenVDB_openvdb_LIBRARY)
+  find_library(OpenVDB_openvdb_LIBRARY
+    NAMES openvdb_sesi openvdb
+    PATHS ${HOUDINI_LIB_DIR}
+    NO_DEFAULT_PATH
+  )
+endif()
+
 # ------------------------------------------------------------------------
 #  Configure OpenVDB ABI
 # ------------------------------------------------------------------------