Support compiling against imath

This change is a revised version of github PR: #1829 - Use Imath's config package (https://github.com/AcademySoftwareFoundation/Imath/blob/main/docs/PortingGuide2-3.md#openexrimath-3x-only) instead of introducing a new FindImath.cmake, this allows for use of modern cmake design. - Attemps to find Imath and if not found, fallbacks to find OpenEXR. - Note on using Alembic plugin: Either OpenEXR or Imath is required depending on which library is used by the Alembic library specified in ALEMBIC_DIR. - Updates pxrConfig.cmake.in to set Imath_DIR accordingly to find the associated import targets which were used for this USD build. Fixes #1591 (Internal change: 2247708)
PixarAnimationStudios · Sep 2, 2022 · 2818017 · 2818017
1 parent 0789ed3
commit 2818017
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Showing 6 changed files with 68 additions and 17 deletions.
diff --git a/BUILDING.md b/BUILDING.md
@@ -247,10 +247,14 @@ by specifying the cmake flag ```PXR_BUILD_ALEMBIC_PLUGIN=TRUE``` when invoking c
 
 The additional dependencies that must be supplied when invoking cmake are:
 
-| Dependency Name    | Description                                       |
-| ------------------ |-------------------------------------------------- |
-| ALEMBIC_DIR        | The location of [Alembic](https://https://github.com/alembic/alembic)   | 
-| OPENEXR_LOCATION   | The location of [OpenEXR](http://www.openexr.com) |
+| Dependency Name                   | Description                                       |
+| ----------------------------------|-------------------------------------------------- |
+| ALEMBIC_DIR                       | The location of [Alembic](https://https://github.com/alembic/alembic)   | 
+| OPENEXR_LOCATION                  | The location of [OpenEXR](http://www.openexr.com) |
+| Imath_DIR (If not using OpenEXR)  | Path to the CMake package config of a Imath SDK install. (With OpenEXR 3+, Imath can be used explicitly instead of OpenEXR.)|
+
+Either OpenEXR or Imath is required depending on which library is used by the
+Alembic library specified in ALEMBIC_DIR.
 
 See [3rd Party Library and Application Versions](VERSIONS.md) for version information.
 

diff --git a/cmake/defaults/Packages.cmake b/cmake/defaults/Packages.cmake
@@ -187,7 +187,7 @@ endif()
 if (PXR_BUILD_IMAGING)
     # --OpenImageIO
     if (PXR_BUILD_OPENIMAGEIO_PLUGIN)
-        find_package(OpenEXR REQUIRED)
+        set(REQUIRES_Imath TRUE)
         find_package(OpenImageIO REQUIRED)
         add_definitions(-DPXR_OIIO_PLUGIN_ENABLED)
         if (OIIO_idiff_BINARY)
@@ -215,7 +215,7 @@ if (PXR_BUILD_IMAGING)
     if (PXR_ENABLE_VULKAN_SUPPORT)
         if (EXISTS $ENV{VULKAN_SDK})
             # Prioritize the VULKAN_SDK includes and packages before any system
-            # installed headers. This is to prevent linking against older SDKs 
+            # installed headers. This is to prevent linking against older SDKs
             # that may be installed by the OS.
             # XXX This is fixed in cmake 3.18+
             include_directories(BEFORE SYSTEM $ENV{VULKAN_SDK} $ENV{VULKAN_SDK}/include $ENV{VULKAN_SDK}/lib)
@@ -256,7 +256,7 @@ if (PXR_BUILD_IMAGING)
     endif()
     # --OpenVDB
     if (PXR_ENABLE_OPENVDB_SUPPORT)
-        find_package(OpenEXR REQUIRED)
+        set(REQUIRES_Imath TRUE)
         find_package(OpenVDB REQUIRED)
         add_definitions(-DPXR_OPENVDB_SUPPORT_ENABLED)
     endif()
@@ -285,7 +285,7 @@ endif()
 
 if (PXR_BUILD_ALEMBIC_PLUGIN)
     find_package(Alembic REQUIRED)
-    find_package(OpenEXR REQUIRED)
+    set(REQUIRES_Imath TRUE)
     if (PXR_ENABLE_HDF5_SUPPORT)
         find_package(HDF5 REQUIRED
             COMPONENTS
@@ -306,10 +306,21 @@ endif()
 
 if(PXR_ENABLE_OSL_SUPPORT)
     find_package(OSL REQUIRED)
-    find_package(OpenEXR REQUIRED)
+    set(REQUIRES_Imath TRUE)
     add_definitions(-DPXR_OSL_SUPPORT_ENABLED)
 endif()
 
 # ----------------------------------------------
 
+# Try and find Imath or fallback to OpenEXR
+# Use ImathConfig.cmake, 
+# Refer: https://github.com/AcademySoftwareFoundation/Imath/blob/main/docs/PortingGuide2-3.md#openexrimath-3x-only
+if(REQUIRES_Imath)
+    find_package(Imath CONFIG)
+    if (NOT Imath_FOUND)
+        MESSAGE(STATUS "Imath not found. Looking for OpenEXR instead.")
+        find_package(OpenEXR REQUIRED)
+    endif()
+endif()
+
 set(BUILD_SHARED_LIBS "${build_shared_libs}")
diff --git a/pxr/imaging/hioOpenVDB/CMakeLists.txt b/pxr/imaging/hioOpenVDB/CMakeLists.txt
@@ -13,14 +13,21 @@ if (WIN32)
     add_definitions(-D_USE_MATH_DEFINES)
 endif()
 
+# Use the import targets set by Imath's package config
+if (Imath_FOUND)
+    LIST(APPEND __VDB_IMATH_LIBS "Imath::Imath")
+else()
+    LIST(APPEND __VDB_IMATH_LIBS ${OPENEXR_Half_LIBRARY})
+endif()
+
 pxr_library(hioOpenVDB
     LIBRARIES
         ar
         gf
         hio
         tf
         usd
-        ${OPENEXR_Half_LIBRARY}
+        ${__VDB_IMATH_LIBS}
         ${OPENVDB_LIBRARY}
 
     INCLUDE_DIRS

diff --git a/pxr/imaging/plugin/hioOiio/CMakeLists.txt b/pxr/imaging/plugin/hioOiio/CMakeLists.txt
@@ -7,6 +7,14 @@ if (NOT ${PXR_BUILD_GPU_SUPPORT})
     return()
 endif()
 
+# Use the import targets set by Imath's package config
+if (Imath_FOUND)
+    set(__OIIO_IMATH_LIBS "Imath::Imath")
+else()
+    set(__OIIO_IMATH_INCLUDE ${OPENEXR_INCLUDE_DIRS})
+    set(__OIIO_IMATH_LIBS ${OPENEXR_LIBRARIES})
+endif()
+
 pxr_plugin(hioOiio
     LIBRARIES
         ar
@@ -15,11 +23,11 @@ pxr_plugin(hioOiio
         hio
         tf
         ${OIIO_LIBRARIES}
-        ${OPENEXR_LIBRARIES}
+        ${__OIIO_IMATH_LIBS}
 
     INCLUDE_DIRS
         ${OIIO_INCLUDE_DIRS}
-        ${OPENEXR_INCLUDE_DIRS}
+        ${__OIIO_IMATH_INCLUDE}
 
     CPPFILES
         oiioImage.cpp

diff --git a/pxr/pxrConfig.cmake.in b/pxr/pxrConfig.cmake.in
@@ -27,6 +27,18 @@ if(@PXR_ENABLE_MATERIALX_SUPPORT@)
     find_package(MaterialX REQUIRED)
 endif()
 
+# Similar to MaterialX above, we are using Imath's cmake package config, so set
+# the Imath_DIR accordingly to find the associated import targets which were
+# used for this USD build. 
+# Note that we only need to do this, when it is determined by Imath is being
+# used instead of OpenExr (refer Packages.cmake)
+if(@REQUIRES_Imath@)
+    if (NOT DEFINED Imath_DIR)
+        set(Imath_DIR "@Imath_DIR@")
+    endif()
+    find_package(Imath REQUIRED)
+endif()
+
 include("${PXR_CMAKE_DIR}/cmake/pxrTargets.cmake")
 set(libs "@PXR_ALL_LIBS@")
 set(PXR_LIBRARIES "")

diff --git a/pxr/usd/plugin/usdAbc/CMakeLists.txt b/pxr/usd/plugin/usdAbc/CMakeLists.txt
@@ -15,6 +15,18 @@ if (PXR_ENABLE_HDF5_SUPPORT)
    list(APPEND optionalIncludeDirs ${HDF5_INCLUDE_DIRS})
 endif()
 
+# Use the import targets set by Imath's package config
+if (Imath_FOUND)
+    set(__ALEMBIC_IMATH_LIBS "Imath::Imath")
+else()
+    set(__ALEMBIC_IMATH_INCLUDES ${OPENEXR_INCLUDE_DIRS})
+    LIST(APPEND __ALEMBIC_IMATH_LIBS ${OPENEXR_Half_LIBRARY})
+    LIST(APPEND __ALEMBIC_IMATH_LIBS ${OPENEXR_Imath_LIBRARY})
+    LIST(APPEND __ALEMBIC_IMATH_LIBS ${OPENEXR_Iex_LIBRARY})
+    LIST(APPEND __ALEMBIC_IMATH_LIBS ${OPENEXR_IexMath_LIBRARY})
+endif()
+
+
 pxr_plugin(usdAbc
     LIBRARIES
         tf
@@ -23,15 +35,12 @@ pxr_plugin(usdAbc
         usd
         usdGeom
         ${ALEMBIC_LIBRARIES}
-        ${OPENEXR_Half_LIBRARY} 
-        ${OPENEXR_Imath_LIBRARY} 
-        ${OPENEXR_Iex_LIBRARY} 
-        ${OPENEXR_IexMath_LIBRARY}
+        ${__ALEMBIC_IMATH_LIBS}
         ${optionalLibs}
 
     INCLUDE_DIRS
         ${ALEMBIC_INCLUDE_DIR}
-        ${OPENEXR_INCLUDE_DIRS}
+        ${__ALEMBIC_IMATH_INCLUDES}
         ${optionalIncludeDirs}
 
     PRIVATE_CLASSES