Index: assimp-5.2.2/samples/SimpleTexturedOpenGL/SimpleTexturedOpenGL/src/model_loading.cpp
===================================================================
--- assimp-5.2.2/samples/SimpleTexturedOpenGL/SimpleTexturedOpenGL/src/model_loading.cpp
+++ assimp-5.2.2/samples/SimpleTexturedOpenGL/SimpleTexturedOpenGL/src/model_loading.cpp	2022-02-26 12:29:59.045701439 +0100
@@ -23,7 +23,7 @@
 #endif // _MSC_VER
 
 #define STB_IMAGE_IMPLEMENTATION
-#include "contrib/stb/stb_image.h"
+#include <stb_image.h>
 
 #ifdef _MSC_VER
 #pragma warning(default: 4100) // Enable warning 'unreferenced formal parameter'
Index: assimp-5.2.2/code/CMakeLists.txt
===================================================================
--- assimp-5.2.2/code/CMakeLists.txt
+++ assimp-5.2.2/code/CMakeLists.txt	2022-02-26 12:29:59.046701438 +0100
@@ -899,12 +899,8 @@
   hunter_add_package(pugixml)
   find_package(pugixml CONFIG REQUIRED)
 ELSE()
-  SET( Pugixml_SRCS
-    ../contrib/pugixml/src/pugiconfig.hpp
-    ../contrib/pugixml/src/pugixml.hpp
-  )
-  INCLUDE_DIRECTORIES("../contrib/pugixml/src")
-  SOURCE_GROUP( Contrib\\Pugixml FILES ${Pugixml_SRCS})
+  find_package(pugixml REQUIRED)
+  include_directories(${pugixml_INCLUDE_DIRS})
 ENDIF()
 
 # utf8
@@ -912,7 +908,7 @@
   hunter_add_package(utf8)
   find_package(utf8cpp CONFIG REQUIRED)
 ELSE()
-  # utf8 is header-only, so Assimp doesn't need to do anything.
+  find_package(utf8cpp)
 ENDIF()
 
 # polyclipping
@@ -920,11 +916,19 @@
   hunter_add_package(polyclipping)
   find_package(polyclipping CONFIG REQUIRED)
 ELSE()
-  SET( Clipper_SRCS
-    ../contrib/clipper/clipper.hpp
-    ../contrib/clipper/clipper.cpp
-  )
-  SOURCE_GROUP( Contrib\\Clipper FILES ${Clipper_SRCS})
+  FIND_LIBRARY(CLIPPER_LIB polyclipping HINTS ${CLIPPER_LIB_PATH})
+  FIND_FILE(CLIPPER_H clipper.hpp PATHS ${CLIPPER_INCLUDE_PATH})
+  IF (CLIPPER_LIB AND CLIPPER_H)
+    MESSAGE(status "Found External clipper")
+    INCLUDE_DIRECTORIES(${CLIPPER_INCLUDE_PATH})
+    SET(Clipper_SRCS "")
+  ELSE()
+    SET( Clipper_SRCS
+      ../contrib/clipper/clipper.hpp
+      ../contrib/clipper/clipper.cpp
+    )
+    SOURCE_GROUP( Contrib\\Clipper FILES ${Clipper_SRCS})
+  ENDIF()
 ENDIF()
 
 # poly2tri
@@ -932,20 +936,14 @@
   hunter_add_package(poly2tri)
   find_package(poly2tri CONFIG REQUIRED)
 ELSE()
-  SET( Poly2Tri_SRCS
-    ../contrib/poly2tri/poly2tri/common/shapes.cc
-    ../contrib/poly2tri/poly2tri/common/shapes.h
-    ../contrib/poly2tri/poly2tri/common/utils.h
-    ../contrib/poly2tri/poly2tri/sweep/advancing_front.h
-    ../contrib/poly2tri/poly2tri/sweep/advancing_front.cc
-    ../contrib/poly2tri/poly2tri/sweep/cdt.cc
-    ../contrib/poly2tri/poly2tri/sweep/cdt.h
-    ../contrib/poly2tri/poly2tri/sweep/sweep.cc
-    ../contrib/poly2tri/poly2tri/sweep/sweep.h
-    ../contrib/poly2tri/poly2tri/sweep/sweep_context.cc
-    ../contrib/poly2tri/poly2tri/sweep/sweep_context.h
-  )
-  SOURCE_GROUP( Contrib\\Poly2Tri FILES ${Poly2Tri_SRCS})
+  FIND_LIBRARY(POLY2TRI_LIB poly2tri)
+  FIND_FILE(POLY2TRI_H poly2tri/poly2tri.h)
+  IF (POLY2TRI_LIB AND POLY2TRI_H)
+    MESSAGE(status "Found External poly2tri")
+    INCLUDE_DIRECTORIES(${POLY2TRI_INCLUDE_PATH})
+    SET(Poly2Tri_SRCS "")
+    SET(SYSTEM_LIBS "${SYSTEM_LIBS} ${POLY2TRI_LIB}")
+  ENDIF()
 ENDIF()
 
 # minizip/unzip
@@ -953,15 +951,9 @@
   hunter_add_package(minizip)
   find_package(minizip CONFIG REQUIRED)
 ELSE()
-  SET( unzip_SRCS
-    ../contrib/unzip/crypt.c
-    ../contrib/unzip/crypt.h
-    ../contrib/unzip/ioapi.c
-    ../contrib/unzip/ioapi.h
-    ../contrib/unzip/unzip.c
-    ../contrib/unzip/unzip.h
-  )
-  SOURCE_GROUP(Contrib\\unzip FILES ${unzip_SRCS})
+  FIND_PATH(MINIZIP_INCLUDE_DIR_zh NAMES minizip/zip.h PATHS /usr/include)
+  FIND_PATH(MINIZIP_INCLUDE_DIR_unzh NAMES minizip/unzip.h PATHS /usr/include)
+  FIND_LIBRARY(MINIZIP_LIBRARY NAMES minizip)
 ENDIF()
 
 # zip (https://github.com/kuba--/zip)
@@ -1046,6 +1038,7 @@
     ../contrib/Open3DGC/o3dgcVector.h
     ../contrib/Open3DGC/o3dgcVector.inl
   )
+  INCLUDE_DIRECTORIES("../contrib")
   SOURCE_GROUP( Contrib\\open3dgc FILES ${open3dgc_SRCS})
 ENDIF()
 
@@ -1067,6 +1060,8 @@
   hunter_add_package(RapidJSON)
   find_package(RapidJSON CONFIG REQUIRED)
 ELSE()
+  #find_package(RapidJSON REQUIRED)
+  #include_directories(${RapidJSON_INCLUDE_DIRS})
   INCLUDE_DIRECTORIES("../contrib/rapidjson/include")
   ADD_DEFINITIONS( -DRAPIDJSON_HAS_STDSTRING=1)
   option( ASSIMP_RAPIDJSON_NO_MEMBER_ITERATOR "Suppress rapidjson warning on MSVC (NOTE: breaks android build)" ON )
@@ -1079,12 +1074,6 @@
 IF(ASSIMP_HUNTER_ENABLED)
   hunter_add_package(stb)
   find_package(stb CONFIG REQUIRED)
-ELSE()
-  SET( stb_SRCS
-    ../contrib/stb/stb_image.h
-  )
-  INCLUDE_DIRECTORIES("../contrib")
-  SOURCE_GROUP( Contrib\\stb FILES ${stb_SRCS})
 ENDIF()
 
 # VC2010 fixes
@@ -1102,15 +1091,6 @@
   ADD_DEFINITIONS( -D_CRT_SECURE_NO_WARNINGS )
 endif ()
 
-IF(NOT ASSIMP_HUNTER_ENABLED)
-  if (UNZIP_FOUND)
-    SET (unzip_compile_SRCS "")
-  else ()
-    SET (unzip_compile_SRCS ${unzip_SRCS})
-    INCLUDE_DIRECTORIES( "../contrib/unzip/" )
-  endif ()
-ENDIF()
-
 MESSAGE(STATUS "Enabled importer formats:${ASSIMP_IMPORTERS_ENABLED}")
 MESSAGE(STATUS "Disabled importer formats:${ASSIMP_IMPORTERS_DISABLED}")
 
@@ -1138,14 +1118,10 @@
   ${ASSIMP_EXPORTER_SRCS}
 
   # Third-party libraries
-  ${unzip_compile_SRCS}
-  ${Poly2Tri_SRCS}
   ${Clipper_SRCS}
   ${openddl_parser_SRCS}
   ${open3dgc_SRCS}
   ${ziplib_SRCS}
-  ${Pugixml_SRCS}
-  ${stb_SRCS}
   # Necessary to show the headers in the project when using the VC++ generator:
 
   ${PUBLIC_HEADERS}
@@ -1212,7 +1188,8 @@
     target_link_libraries(assimp PUBLIC ${draco_LIBRARIES})
   endif()
 ELSE()
-  TARGET_LINK_LIBRARIES(assimp ${ZLIB_LIBRARIES} ${OPENDDL_PARSER_LIBRARIES})
+  TARGET_LINK_LIBRARIES(assimp ${ZLIB_LIBRARIES} ${OPENDDL_PARSER_LIBRARIES}
+      poly2tri minizip pugixml stbi)
   if (ASSIMP_BUILD_DRACO)
     target_link_libraries(assimp ${draco_LIBRARIES})
   endif()
Index: assimp-5.2.2/code/AssetLib/Blender/BlenderTessellator.h
===================================================================
--- assimp-5.2.2/code/AssetLib/Blender/BlenderTessellator.h
+++ assimp-5.2.2/code/AssetLib/Blender/BlenderTessellator.h	2022-02-26 12:29:59.047701437 +0100
@@ -144,11 +144,7 @@
 
 #if ASSIMP_BLEND_WITH_POLY_2_TRI
 
-#ifdef ASSIMP_USE_HUNTER
-#  include <poly2tri/poly2tri.h>
-#else
-#  include "../contrib/poly2tri/poly2tri/poly2tri.h"
-#endif
+#include <poly2tri/poly2tri.h>
 
 namespace Assimp
 {
Index: assimp-5.2.2/code/AssetLib/MMD/MMDPmxParser.cpp
===================================================================
--- assimp-5.2.2/code/AssetLib/MMD/MMDPmxParser.cpp
+++ assimp-5.2.2/code/AssetLib/MMD/MMDPmxParser.cpp	2022-02-26 12:29:59.047701437 +0100
@@ -42,11 +42,7 @@
 #include <utility>
 #include "MMDPmxParser.h"
 #include <assimp/StringUtils.h>
-#ifdef ASSIMP_USE_HUNTER
-#  include <utf8.h>
-#else
-#  include "../contrib/utf8cpp/source/utf8.h"
-#endif
+#include <utf8.h>
 #include <assimp/Exceptional.h>
 
 namespace pmx
Index: assimp-5.2.2/code/AssetLib/IFC/IFCGeometry.cpp
===================================================================
--- assimp-5.2.2/code/AssetLib/IFC/IFCGeometry.cpp
+++ assimp-5.2.2/code/AssetLib/IFC/IFCGeometry.cpp	2022-02-26 12:29:59.048701436 +0100
@@ -49,13 +49,8 @@
 #include "Common/PolyTools.h"
 #include "PostProcessing/ProcessHelper.h"
 
-#ifdef ASSIMP_USE_HUNTER
-#  include <poly2tri/poly2tri.h>
-#  include <polyclipping/clipper.hpp>
-#else
-#  include "../contrib/poly2tri/poly2tri/poly2tri.h"
-#  include "../contrib/clipper/clipper.hpp"
-#endif
+#include <poly2tri/poly2tri.h>
+#include <../contrib/clipper/clipper.hpp>
 
 #include <memory>
 #include <iterator>
Index: assimp-5.2.2/code/AssetLib/IFC/IFCLoader.cpp
===================================================================
--- assimp-5.2.2/code/AssetLib/IFC/IFCLoader.cpp
+++ assimp-5.2.2/code/AssetLib/IFC/IFCLoader.cpp	2022-02-26 12:29:59.048701436 +0100
@@ -51,11 +51,7 @@
 #include <tuple>
 
 #ifndef ASSIMP_BUILD_NO_COMPRESSED_IFC
-#ifdef ASSIMP_USE_HUNTER
 #include <minizip/unzip.h>
-#else
-#include <unzip.h>
-#endif
 #endif
 
 #include "../STEPParser/STEPFileReader.h"
Index: assimp-5.2.2/code/AssetLib/IFC/IFCOpenings.cpp
===================================================================
--- assimp-5.2.2/code/AssetLib/IFC/IFCOpenings.cpp
+++ assimp-5.2.2/code/AssetLib/IFC/IFCOpenings.cpp	2022-02-26 12:29:59.049701435 +0100
@@ -49,13 +49,8 @@
 #include "Common/PolyTools.h"
 #include "PostProcessing/ProcessHelper.h"
 
-#ifdef ASSIMP_USE_HUNTER
-#  include <poly2tri/poly2tri.h>
-#  include <polyclipping/clipper.hpp>
-#else
-#  include "../contrib/poly2tri/poly2tri/poly2tri.h"
-#  include "../contrib/clipper/clipper.hpp"
-#endif
+#include <poly2tri/poly2tri.h>
+#include <../contrib/clipper/clipper.hpp>
 
 #include <iterator>
 #include <forward_list>
Index: assimp-5.2.2/code/AssetLib/STEPParser/STEPFileEncoding.cpp
===================================================================
--- assimp-5.2.2/code/AssetLib/STEPParser/STEPFileEncoding.cpp
+++ assimp-5.2.2/code/AssetLib/STEPParser/STEPFileEncoding.cpp	2022-02-26 12:29:59.049701435 +0100
@@ -45,11 +45,7 @@
  */
 #include "STEPFileEncoding.h"
 #include <assimp/fast_atof.h>
-#ifdef ASSIMP_USE_HUNTER
-#  include <utf8.h>
-#else
-#  include <contrib/utf8cpp/source/utf8.h>
-#endif
+#include <utf8.h>
 
 #include <memory>
 
Index: assimp-5.2.2/code/AssetLib/SIB/SIBImporter.cpp
===================================================================
--- assimp-5.2.2/code/AssetLib/SIB/SIBImporter.cpp
+++ assimp-5.2.2/code/AssetLib/SIB/SIBImporter.cpp	2022-02-26 12:29:59.049701435 +0100
@@ -56,11 +56,7 @@
 #include <assimp/ByteSwapper.h>
 #include <assimp/StreamReader.h>
 #include <assimp/TinyFormatter.h>
-#ifdef ASSIMP_USE_HUNTER
 #include <utf8.h>
-#else
-#include "../contrib/utf8cpp/source/utf8.h"
-#endif
 #include <assimp/importerdesc.h>
 #include <assimp/scene.h>
 #include <assimp/DefaultLogger.hpp>
Index: assimp-5.2.2/code/Pbrt/PbrtExporter.cpp
===================================================================
--- assimp-5.2.2/code/Pbrt/PbrtExporter.cpp
+++ assimp-5.2.2/code/Pbrt/PbrtExporter.cpp	2022-02-26 12:29:59.049701435 +0100
@@ -83,7 +83,7 @@
 #include <sstream>
 #include <string>
 
-#include "stb/stb_image.h"
+#include <stb_image.h>
 
 using namespace Assimp;
 
Index: assimp-5.2.2/code/Common/Assimp.cpp
===================================================================
--- assimp-5.2.2/code/Common/Assimp.cpp
+++ assimp-5.2.2/code/Common/Assimp.cpp	2022-02-26 12:29:59.049701435 +0100
@@ -1290,7 +1290,7 @@
 #   endif
 
 #   define STB_IMAGE_IMPLEMENTATION
-#   include "stb/stb_image.h"
+#   include <stb_image.h>
 
 #   if _MSC_VER
 #       pragma warning(pop)
Index: assimp-5.2.2/code/Common/BaseImporter.cpp
===================================================================
--- assimp-5.2.2/code/Common/BaseImporter.cpp
+++ assimp-5.2.2/code/Common/BaseImporter.cpp	2022-02-26 12:29:59.050701434 +0100
@@ -329,11 +329,7 @@
     return false;
 }
 
-#ifdef ASSIMP_USE_HUNTER
 #include <utf8.h>
-#else
-#include "../contrib/utf8cpp/source/utf8.h"
-#endif
 
 // ------------------------------------------------------------------------------------------------
 // Convert to UTF8 data
Index: assimp-5.2.2/code/Common/ZipArchiveIOSystem.cpp
===================================================================
--- assimp-5.2.2/code/Common/ZipArchiveIOSystem.cpp
+++ assimp-5.2.2/code/Common/ZipArchiveIOSystem.cpp	2022-02-26 12:30:37.431665924 +0100
@@ -51,11 +51,7 @@
 #include <map>
 #include <memory>
 
-#ifdef ASSIMP_USE_HUNTER
-#    include <minizip/unzip.h>
-#else
-#    include <unzip.h>
-#endif
+#include <minizip/unzip.h>
 
 namespace Assimp {
 
@@ -196,7 +192,9 @@
     zlib_filefunc_def mapping;
 
     mapping.zopen_file = (open_file_func)open;
+#ifdef ZOPENDISK64
     mapping.zopendisk_file = (opendisk_file_func)opendisk;
+#endif
     mapping.zread_file = (read_file_func)read;
     mapping.zwrite_file = (write_file_func)write;
     mapping.ztell_file = (tell_file_func)tell;