Add separate build step for OpenUSD to third_party_deps.

This will fetch and call the build_usd.py build helper for OpenUSD and build within the MuJoCo _deps folder. Simplifying the build process for MuJoCo with USD. Users can still provide their own USD build, but must now do so via pxr_DIR.

PiperOrigin-RevId: 846735578
Change-Id: I0da7eb2da6465e2d518084340e762bf370adb6d5

Author: havess

CMakeLists.txt

@@ -54,25 +54,6 @@ if(EMSCRIPTEN)
   option(MUJOCO_BUILD_TESTS_WASM "Build tests for WASM bindings" ON)
 endif()
 
-# Option to provide a path to an existing USD build directory or to Houdini HFS directory.
-set(USD_DIR "" CACHE PATH "Path to an existing USD build directory.")
-set(HOUDINI_HFS_DIR "" CACHE PATH "Path to Houdini HFS directory to build USD plugins against.")
-if(USD_DIR)
-  if(EXISTS "${USD_DIR}")
-    # If the path is provided, set MUJOCO_WITH_USD to ON and add the path to CMAKE_PREFIX_PATH.
-    set(MUJOCO_WITH_USD ON CACHE BOOL "Build with OpenUSD" FORCE)
-    list(PREPEND CMAKE_PREFIX_PATH "${USD_DIR}")
-    message(STATUS "Using custom USD build directory: ${USD_DIR}")
-  else()
-    message(WARNING "Invalid path provided for USD_DIR: ${USD_DIR}")
-  endif()
-elseif(HOUDINI_HFS_DIR)
-  if(EXISTS "${HOUDINI_HFS_DIR}")
-    set(MUJOCO_WITH_USD ON CACHE BOOL "Build with OpenUSD" FORCE)
-    message(STATUS "Building Mujoco USD against Houdini HFS: ${HOUDINI_HFS_DIR}")
-  endif()
-endif()
-
 if(APPLE AND (MUJOCO_BUILD_EXAMPLES OR MUJOCO_BUILD_SIMULATE))
   enable_language(OBJC)
   enable_language(OBJCXX)
@@ -243,7 +224,24 @@ if(MUJOCO_BUILD_EXAMPLES)
 endif()
 
 if(MUJOCO_WITH_USD)
-  target_compile_definitions(mujoco PUBLIC mjUSEUSD)
+  include(third_party_deps/openusd)
+
+  get_filename_component(USD_INSTALL_ROOT "${pxr_DIR}/lib" ABSOLUTE)
+  install(
+    DIRECTORY ${USD_INSTALL_ROOT}/
+    DESTINATION ${CMAKE_INSTALL_LIBDIR}
+  )
+
+  if(APPLE)
+    set_target_properties(mujoco PROPERTIES
+      BUILD_RPATH "${USD_INSTALL_ROOT}"
+      INSTALL_RPATH "@loader_path")
+  elseif(UNIX)
+    set_target_properties(mujoco PROPERTIES
+      BUILD_RPATH "${USD_INSTALL_ROOT}"
+      INSTALL_RPATH "$ORIGIN")
+  endif()
+
   add_subdirectory(src/experimental/usd)
 endif()
 

cmake/third_party_deps/openusd.cmake

@@ -0,0 +1,38 @@
+# Copyright 2025 DeepMind Technologies Limited
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Find OpenUSD package. The user can either provide pxr_DIR to use their own
+# OpenUSD installation or they can build external_dependencies.
+#
+# We use QUIET here to provide a better error message when pxr is not found.
+find_package(pxr
+  QUIET
+  HINTS "${CMAKE_BINARY_DIR}/_deps/openusd-build"
+)
+
+if(NOT pxr_FOUND)
+    message(FATAL_ERROR
+        "-----------------------------------------------------------\n"
+        "USD Configuration Error:\n${pxr_NOT_FOUND_MESSAGE}\n"
+        "If you have built USD yourself, provide -Dpxr_DIR=your_pxr_install_dir' \n"
+        "Otherwise you can build cmake/third_party_deps/openusd:\n"
+        "cd ~/mujoco\n"
+        "cmake -Bcmake/third_party_deps/openusd/build cmake/third_party_deps/openusd -DBUILD_USD=True\n"
+        "cmake --build cmake/third_party_deps/openusd/build\n"
+        "cmake -Bbuild -S. -DMUJOCO_WITH_USD=True\n"
+        "cmake --build build\n"
+        "cmake --install build"
+        "-----------------------------------------------------------"
+    )
+endif()

cmake/third_party_deps/openusd/CMakeLists.txt

@@ -0,0 +1,54 @@
+# Copyright 2025 DeepMind Technologies Limited
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+cmake_minimum_required(VERSION "3.16")
+
+option(BUILD_USD OFF "Build OpenUSD")
+project(openusd-dependency)
+
+if (BUILD_USD)
+  include(ExternalProject)
+
+  set(DEPS_DIR ${CMAKE_BINARY_DIR}/../../../../build/_deps)
+
+  ExternalProject_Add(openusd
+    GIT_REPOSITORY https://github.com/PixarAnimationStudios/USD.git
+    GIT_TAG v25.11
+    PREFIX openusd
+    BUILD_IN_SOURCE 0
+    UPDATE_COMMAND ""
+    CONFIGURE_COMMAND ""
+    INSTALL_COMMAND ""
+    SOURCE_DIR ${DEPS_DIR}/openusd-src
+    BINARY_DIR ${DEPS_DIR}/openusd-build
+    INSTALL_DIR ${DEPS_DIR}/openusd-build
+    BUILD_COMMAND python3 ${DEPS_DIR}/openusd-src/build_scripts/build_usd.py
+        --build-shared
+        --no-examples
+        --no-tools
+        --no-ptex
+        --no-prman
+        --no-openimageio
+        --no-opencolorio
+        --no-alembic
+        --no-draco
+        --no-materialx
+        --no-tutorials
+        --no-tests
+        --no-docs
+        --no-imaging
+        --no-python
+        --no-usdValidation
+        <INSTALL_DIR>
+  )
+endif()

simulate/CMakeLists.txt

@@ -185,7 +185,7 @@ if(SIMULATE_BUILD_EXECUTABLE)
     target_link_libraries(simulate "-framework CoreVideo")
   endif()
 
-  if (MUJOCO_WITH_USD)
+  if (BUILD_WITH_USD)
     # pxr/usd/tf/hashset.h might include deprecated headers so disable this check
     # when compiling with USD enabled.
     target_compile_options(
@@ -265,8 +265,13 @@ if(SIMULATE_BUILD_EXECUTABLE)
       MUJOCO_ENABLE_RPATH
     )
 
-    if (MUJOCO_WITH_USD)
-      target_compile_definitions(simulate PUBLIC mjUSEUSD)
+    if (BUILD_WITH_USD)
+      # pxr/usd/tf/hashset.h might include deprecated headers so disable this check
+      # when compiling with USD enabled.
+      target_compile_options(
+         simulate
+         PRIVATE -Wno-deprecated
+      )
 
       # Add support to RPATH for the samples.
       target_add_rpath(
@@ -275,10 +280,13 @@ if(SIMULATE_BUILD_EXECUTABLE)
         INSTALL_DIRECTORY
         "${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_BINDIR}"
         LIB_DIRS
-        ${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR}/mujocoUsd ${USD_DIR}/lib
         DEPENDS
         MUJOCO_ENABLE_RPATH
       )
+
+      # Do we need this?
+      #target_link_options(simulate PRIVATE -rpath=${pxr_DIR}/lib)
+
     endif()
 
     if(NOT MUJOCO_SIMULATE_USE_SYSTEM_GLFW)