--- /dev/null
+Index: Field3D-1.7.3/export/StdMathLib.h
+===================================================================
+--- Field3D-1.7.3.orig/export/StdMathLib.h
++++ Field3D-1.7.3/export/StdMathLib.h
+@@ -38,18 +38,41 @@
+ #ifndef _INCLUDED_Field3D_StdMathLib_H_
+ #define _INCLUDED_Field3D_StdMathLib_H_
+
+-#include <OpenEXR/ImathBox.h>
+-#include <OpenEXR/ImathBoxAlgo.h>
+-#include <OpenEXR/ImathColor.h>
+-#include <OpenEXR/ImathHalfLimits.h>
+-#include <OpenEXR/ImathMatrix.h>
+-#include <OpenEXR/ImathMatrixAlgo.h>
+-#include <OpenEXR/ImathPlane.h>
+-#include <OpenEXR/ImathRandom.h>
+-#include <OpenEXR/ImathRoots.h>
+-#include <OpenEXR/ImathVec.h>
+-#include <OpenEXR/half.h>
++// The version can reliably be found in this header file from OpenEXR,
++// for both 2.x and 3.x:
++#include <OpenEXR/OpenEXRConfig.h>
++#define COMBINED_OPENEXR_VERSION ((10000*OPENEXR_VERSION_MAJOR) + \
++ (100*OPENEXR_VERSION_MINOR) + \
++ OPENEXR_VERSION_PATCH)
+
++// There's just no easy way to have an `#include` that works in both
++// cases, so we use the version to switch which set of include files we
++// use.
++#if COMBINED_OPENEXR_VERSION >= 20599 /* 2.5.99: pre-3.0 */
++# include <Imath/ImathBox.h>
++# include <Imath/ImathBoxAlgo.h>
++# include <Imath/ImathColor.h>
++# include <Imath/ImathMatrix.h>
++# include <Imath/ImathMatrixAlgo.h>
++# include <Imath/ImathPlane.h>
++# include <Imath/ImathRandom.h>
++# include <Imath/ImathRoots.h>
++# include <Imath/ImathVec.h>
++# include <Imath/half.h>
++#else
++ // OpenEXR 2.x, use the old locations
++# include <OpenEXR/ImathBox.h>
++# include <OpenEXR/ImathBoxAlgo.h>
++# include <OpenEXR/ImathColor.h>
++# include <OpenEXR/ImathHalfLimits.h>
++# include <OpenEXR/ImathMatrix.h>
++# include <OpenEXR/ImathMatrixAlgo.h>
++# include <OpenEXR/ImathPlane.h>
++# include <OpenEXR/ImathRandom.h>
++# include <OpenEXR/ImathRoots.h>
++# include <OpenEXR/ImathVec.h>
++# include <OpenEXR/half.h>
++#endif
+ //----------------------------------------------------------------------------//
+
+ #include "ns.h"
+Index: Field3D-1.7.3/export/Curve.h
+===================================================================
+--- Field3D-1.7.3.orig/export/Curve.h
++++ Field3D-1.7.3/export/Curve.h
+@@ -53,8 +53,25 @@
+
+ #include <boost/lexical_cast.hpp>
+
+-#include <OpenEXR/ImathFun.h>
+-#include <OpenEXR/ImathMatrix.h>
++// The version can reliably be found in this header file from OpenEXR,
++// for both 2.x and 3.x:
++#include <OpenEXR/OpenEXRConfig.h>
++#define COMBINED_OPENEXR_VERSION ((10000*OPENEXR_VERSION_MAJOR) + \
++ (100*OPENEXR_VERSION_MINOR) + \
++ OPENEXR_VERSION_PATCH)
++
++// There's just no easy way to have an `#include` that works in both
++// cases, so we use the version to switch which set of include files we
++// use.
++#if COMBINED_OPENEXR_VERSION >= 20599 /* 2.5.99: pre-3.0 */
++# include <Imath/ImathFun.h>
++# include <Imath/ImathMatrix.h>
++#else
++ // OpenEXR 2.x, use the old locations
++# include <OpenEXR/ImathFun.h>
++# include <OpenEXR/ImathMatrix.h>
++#endif
++
+
+ //----------------------------------------------------------------------------//
+
+Index: Field3D-1.7.3/include/OgUtil.h
+===================================================================
+--- Field3D-1.7.3.orig/include/OgUtil.h
++++ Field3D-1.7.3/include/OgUtil.h
+@@ -10,7 +10,22 @@
+ #include <iostream>
+ #include <string>
+
+-#include <OpenEXR/ImathVec.h>
++// The version can reliably be found in this header file from OpenEXR,
++// for both 2.x and 3.x:
++#include <OpenEXR/OpenEXRConfig.h>
++#define COMBINED_OPENEXR_VERSION ((10000*OPENEXR_VERSION_MAJOR) + \
++ (100*OPENEXR_VERSION_MINOR) + \
++ OPENEXR_VERSION_PATCH)
++
++// There's just no easy way to have an `#include` that works in both
++// cases, so we use the version to switch which set of include files we
++// use.
++#if COMBINED_OPENEXR_VERSION >= 20599 /* 2.5.99: pre-3.0 */
++# include <Imath/ImathVec.h>
++#else
++ // OpenEXR 2.x, use the old locations
++# include <OpenEXR/ImathVec.h>
++#endif
+
+ #include "All.h"
+ #include "UtilFoundation.h"
+Index: Field3D-1.7.3/include/UtilFoundation.h
+===================================================================
+--- Field3D-1.7.3.orig/include/UtilFoundation.h
++++ Field3D-1.7.3/include/UtilFoundation.h
+@@ -68,7 +68,22 @@
+
+ #include <memory>
+
+-#include <half.h>
++// The version can reliably be found in this header file from OpenEXR,
++// for both 2.x and 3.x:
++#include <OpenEXR/OpenEXRConfig.h>
++#define COMBINED_OPENEXR_VERSION ((10000*OPENEXR_VERSION_MAJOR) + \
++ (100*OPENEXR_VERSION_MINOR) + \
++ OPENEXR_VERSION_PATCH)
++
++// There's just no easy way to have an `#include` that works in both
++// cases, so we use the version to switch which set of include files we
++// use.
++#if COMBINED_OPENEXR_VERSION >= 20599 /* 2.5.99: pre-3.0 */
++# include <Imath/half.h>
++#else
++ // OpenEXR 2.x, use the old locations
++# include <OpenEXR/half.h>
++#endif
+
+ #include <iomanip>
+ #include <iostream>
+Index: Field3D-1.7.3/include/OgIAttribute.h
+===================================================================
+--- Field3D-1.7.3.orig/include/OgIAttribute.h
++++ Field3D-1.7.3/include/OgIAttribute.h
+@@ -9,7 +9,22 @@
+
+ #include "OgUtil.h"
+
+-#include <OpenEXR/ImathMatrix.h>
++// The version can reliably be found in this header file from OpenEXR,
++// for both 2.x and 3.x:
++#include <OpenEXR/OpenEXRConfig.h>
++#define COMBINED_OPENEXR_VERSION ((10000*OPENEXR_VERSION_MAJOR) + \
++ (100*OPENEXR_VERSION_MINOR) + \
++ OPENEXR_VERSION_PATCH)
++
++// There's just no easy way to have an `#include` that works in both
++// cases, so we use the version to switch which set of include files we
++// use.
++#if COMBINED_OPENEXR_VERSION >= 20599 /* 2.5.99: pre-3.0 */
++# include <Imath/ImathMatrix.h>
++#else
++ // OpenEXR 2.x, use the old locations
++# include <OpenEXR/ImathMatrix.h>
++#endif
+
+ //----------------------------------------------------------------------------//
+
+Index: Field3D-1.7.3/CMakeLists.txt
+===================================================================
+--- Field3D-1.7.3.orig/CMakeLists.txt
++++ Field3D-1.7.3/CMakeLists.txt
+@@ -38,7 +38,6 @@
+ set( CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${PROJECT_SOURCE_DIR}/cmake )
+
+ FIND_PACKAGE (Doxygen)
+-FIND_PACKAGE (HDF5 COMPONENTS C)
+ IF ( CMAKE_HOST_WIN32 )
+ # f3dinfo relies on program_options but don't include it, since
+ # for some reason, unlike all the other boost components, a link is
+@@ -49,7 +49,14 @@ FIND_PACKAGE (Boost COMPONENTS regex thr
+ FIND_PACKAGE (MPI)
+ ENDIF ()
+
+-FIND_PACKAGE (ILMBase)
++# First, try to find just the right config files
++find_package(Imath CONFIG)
++if (NOT TARGET Imath::Imath)
++ # Couldn't find Imath::Imath, maybe it's older and has IlmBase?
++ find_package(IlmBase CONFIG)
++endif ()
++find_package(OpenEXR CONFIG)
++find_package(HDF5 COMPONENTS C)
+
+ # Allow the developer to select if Dynamic or Static libraries are built
+ OPTION (BUILD_SHARED_LIBS "Build Shared Libraries" ON)
+@@ -146,9 +152,20 @@ IF ( CMAKE_HOST_UNIX )
+ LIST ( APPEND Field3D_Libraries_Shared
+ ${MPI_LIBRARIES} )
+ ENDIF ( MPI_FOUND )
+- LIST ( APPEND Field3D_Libraries_Shared
+- Iex Half IlmThread Imath
+- pthread dl z )
++ if(TARGET Imath::Imath)
++ list(APPEND Field3D_Libraries_Shared
++ # For OpenEXR/Imath 3.x:
++ $<$<TARGET_EXISTS:OpenEXR::OpenEXR>:OpenEXR::OpenEXR>
++ $<$<TARGET_EXISTS:Imath::Imath>:Imath::Imath>
++ $<$<TARGET_EXISTS:Imath::Half>:Imath::Half>
++ pthread
++ dl
++ z)
++ else()
++ LIST ( APPEND Field3D_Libraries_Shared
++ Iex Half IlmThread Imath
++ pthread dl z )
++ endif()
+ SET ( Field3D_DSO_Libraries ${Field3D_Libraries_Shared} )
+ SET ( Field3D_BIN_Libraries Field3D ${Field3D_Libraries_Shared}
+ ${Boost_LIBRARIES} )
+Index: Field3D-1.7.3/test/unit_tests/UnitTest.cpp
+===================================================================
+--- Field3D-1.7.3.orig/test/unit_tests/UnitTest.cpp
++++ Field3D-1.7.3/test/unit_tests/UnitTest.cpp
+@@ -44,7 +44,22 @@
+ #include <boost/thread/thread.hpp>
+ #include <boost/thread/mutex.hpp>
+
+-#include <OpenEXR/ImathFrustum.h>
++// The version can reliably be found in this header file from OpenEXR,
++// for both 2.x and 3.x:
++#include <OpenEXR/OpenEXRConfig.h>
++#define COMBINED_OPENEXR_VERSION ((10000*OPENEXR_VERSION_MAJOR) + \
++ (100*OPENEXR_VERSION_MINOR) + \
++ OPENEXR_VERSION_PATCH)
++
++// There's just no easy way to have an `#include` that works in both
++// cases, so we use the version to switch which set of include files we
++// use.
++#if COMBINED_OPENEXR_VERSION >= 20599 /* 2.5.99: pre-3.0 */
++# include <Imath/ImathFrustum.h>
++#else
++ // OpenEXR 2.x, use the old locations
++# include <OpenEXR/ImathFrustum.h>
++#endif
+
+ #include "Field3D/DenseField.h"
+ #include "Field3D/EmptyField.h"