Do not build ziplib when 3MF exporter is disabled.

code/CMakeLists.txt

@@ -934,24 +934,26 @@ ELSE()
 ENDIF()
 
 # zip (https://github.com/kuba--/zip)
-IF(ASSIMP_HUNTER_ENABLED)
-  hunter_add_package(zip)
-  find_package(zip CONFIG REQUIRED)
-ELSE()
-  SET( ziplib_SRCS
-    ../contrib/zip/src/miniz.h
-    ../contrib/zip/src/zip.c
-    ../contrib/zip/src/zip.h
-  )
+IF(3MF IN_LIST ASSIMP_EXPORTERS_ENABLED)
+  IF(ASSIMP_HUNTER_ENABLED)
+    hunter_add_package(zip)
+    find_package(zip CONFIG REQUIRED)
+  ELSE()
+    SET( ziplib_SRCS
+      ../contrib/zip/src/miniz.h
+      ../contrib/zip/src/zip.c
+      ../contrib/zip/src/zip.h
+    )
 
-  # TODO if cmake required version has been updated to >3.12.0, collapse this to the second case only
-  if(${CMAKE_VERSION} VERSION_LESS "3.12.0")
-  	add_definitions(-DMINIZ_USE_UNALIGNED_LOADS_AND_STORES=0)
-  else()
-  	add_compile_definitions(MINIZ_USE_UNALIGNED_LOADS_AND_STORES=0)
-  endif()
+    # TODO if cmake required version has been updated to >3.12.0, collapse this to the second case only
+    if(${CMAKE_VERSION} VERSION_LESS "3.12.0")
+      add_definitions(-DMINIZ_USE_UNALIGNED_LOADS_AND_STORES=0)
+    else()
+      add_compile_definitions(MINIZ_USE_UNALIGNED_LOADS_AND_STORES=0)
+    endif()
 
-  SOURCE_GROUP( ziplib FILES ${ziplib_SRCS} )
+    SOURCE_GROUP( ziplib FILES ${ziplib_SRCS} )
+  ENDIF()
 ENDIF()
 
 # openddlparser
@@ -1153,10 +1155,12 @@ IF(ASSIMP_HUNTER_ENABLED)
       ZLIB::zlib
       RapidJSON::rapidjson
       utf8cpp
-      zip::zip
       pugixml
   )
-  
+  if(TARGET zip::zip)
+    target_link_libraries(assimp PUBLIC zip::zip)
+  endif()
+
   if (ASSIMP_BUILD_DRACO)
     target_link_libraries(assimp PUBLIC ${draco_LIBRARIES})
   endif()