make SDF to USD a separate component of sdformat

.github/ci/before_cmake.sh

@@ -0,0 +1,58 @@
+#!/bin/sh -l
+
+set -x
+
+BUILD_DIR=`pwd`
+
+cd /tmp
+
+# check that we can compile USD from sources (only Focal)
+mkdir cmake_test
+cd cmake_test
+
+echo "cmake_minimum_required(VERSION 3.12)" > CMakeLists.txt
+
+return_code=0
+cmake . || return_code=$(($return_code + $?))
+if [ $return_code -eq 0 ]
+then
+  # compile USD from sources
+  cd /tmp
+  mkdir usd_binaries
+  cd usd_binaries
+
+  apt-get install libboost-all-dev libtbb-dev p7zip-full -y
+
+  wget https://github.com/PixarAnimationStudios/USD/archive/refs/tags/v21.11.zip
+  unzip v21.11.zip
+  sed -i '2059 i \ \ \ \ requiredDependencies.remove(BOOST)' USD-21.11/build_scripts/build_usd.py
+  cd USD-21.11
+  mkdir build
+  cd build
+
+  cmake -DCMAKE_INSTALL_PREFIX="/tmp/USD" -DCMAKE_PREFIX_PATH="/tmp/USD" \
+    -DCMAKE_BUILD_TYPE=Release \
+    -DPXR_PREFER_SAFETY_OVER_SPEED=ON \
+    -DPXR_ENABLE_PYTHON_SUPPORT=OFF \
+    -DBUILD_SHARED_LIBS=ON  \
+    -DTBB_USE_DEBUG_BUILD=OFF  \
+    -DPXR_BUILD_DOCUMENTATION=OFF  \
+    -DPXR_BUILD_TESTS=OFF  \
+    -DPXR_BUILD_EXAMPLES=OFF  \
+    -DPXR_BUILD_TUTORIALS=OFF  \
+    -DPXR_BUILD_USD_TOOLS=OFF  \
+    -DPXR_BUILD_IMAGING=OFF  \
+    -DPXR_BUILD_USD_IMAGING=OFF  \
+    -DPXR_BUILD_USDVIEW=OFF  \
+    -DPXR_BUILD_ALEMBIC_PLUGIN=OFF  \
+    -DPXR_BUILD_DRACO_PLUGIN=OFF  \
+    -DPXR_ENABLE_MATERIALX_SUPPORT=OFF  \
+    -DBoost_NO_BOOST_CMAKE=On  \
+    -DBoost_INCLUDE_DIR=/usr/include  \
+    -DBoost_NO_BOOST_CMAKE=FALSE \
+    ..
+
+  make -j$(nproc) install
+fi
+
+cd $BUILD_DIR

.github/ci/packages.apt

@@ -1,7 +1,9 @@
+libignition-common4-dev
 libignition-cmake2-dev
 libignition-math6-dev
 libignition-tools-dev
 libignition-utils1-dev
+libignition-utils1-cli-dev
 libtinyxml2-dev
 liburdfdom-dev
 libxml2-utils

.github/workflows/ci.yml

@@ -18,6 +18,11 @@ jobs:
     runs-on: ubuntu-latest
     name: Ubuntu Focal CI
     steps:
+      - name: Set env
+        run: |
+          echo "PATH=$PATH:/tmp/USD/bin" >> $GITHUB_ENV
+          echo "LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/tmp/USD/lib" >> $GITHUB_ENV
+          echo "CMAKE_PREFIX_PATH=$CMAKE_PREFIX_PATH:/tmp/USD" >> $GITHUB_ENV
       - name: Checkout
         uses: actions/checkout@v2
       - name: Compile and test

CMakeLists.txt

@@ -109,8 +109,18 @@ if (BUILD_SDF)
   ign_find_package(ignition-utils1 VERSION REQUIRED)
   set(IGN_UTILS_VER ${ignition-utils1_VERSION_MAJOR})
 
+  ########################################
+  # Find ignition common
+  ign_find_package(ignition-common4 COMPONENTS graphics REQUIRED_BY usd)
+  set(IGN_COMMON_VER ${ignition-common4_VERSION_MAJOR})
+
+  ########################################
+  # Find PXR
+  ign_find_package(pxr QUIET REQUIRED_BY usd PKGCONFIG pxr)
+
+  ign_configure_build(HIDE_SYMBOLS_BY_DEFAULT QUIT_IF_BUILD_ERRORS
+    COMPONENTS usd)
 
-  ign_configure_build(HIDE_SYMBOLS_BY_DEFAULT QUIT_IF_BUILD_ERRORS)
   ign_create_packages()
 
   add_subdirectory(sdf)

examples/usdConverter/README.md

@@ -0,0 +1,63 @@
+# Converting between SDF and USD
+
+This example shows how a world in a SDF file can be converted to [USD](https://graphics.pixar.com/usd/release/index.html).
+
+## Requirements
+
+You will need all of the dependencies for sdformat, along with the following additional dependencies:
+* USD: [installation instructions](https://github.com/PixarAnimationStudios/USD/blob/release/README.md#getting-and-building-the-code)
+* [ignition-common4](https://github.com/ignitionrobotics/ign-common)
+* [ignition-utils1 (including the CLI component)](https://github.com/ignitionrobotics/ign-utils)
+
+## Setup
+
+Build sdformat. The steps below follow a traditional cmake build, but sdformat
+can also be built with [colcon](https://colcon.readthedocs.io/en/released/index.html):
+```bash
+git clone https://github.com/ignitionrobotics/sdformat.git
+cd sdformat
+mkdir build
+cd build
+cmake ..
+make
+```
+
+You should now have an executable named `sdf2usd` in the `sdformat/build/bin` directory.
+This executable can be used to convert a SDF world file to a USD file.
+To see how the executable works, run the following command from the `sdformat/build/bin` directory:
+```bash
+./sdf2usd -h
+```
+
+To convert [shapes_world.sdf](https://github.com/ignitionrobotics/sdformat/blob/sdf12/test/sdf/shapes_world.sdf) to its USD representation as a file called `shapes.usd`, run the following commands:
+
+```bash
+wget https://raw.githubusercontent.com/ignitionrobotics/sdformat/sdf12/test/sdf/shapes_world.sdf
+./sdf2usd shapes_world.sdf shapes.usd
+```
+
+You can now view the contents of the generated USD file with `usdcat` (this should have been installed when setting up the USD dependency):
+```bash
+usdcat shapes.usd
+```
+
+To see the visual representation of the USD world, run `usdview` (this should have also been installed when setting up the USD dependency):
+```bash
+usdview shapes.usd
+```
+
+### Note about building with colcon
+You may need to add the USD library path to your `LD_LIBRARY_PATH` environment variable after sourcing the colcon workspace.
+If the USD library path is not a part of `LD_LIBRARY_PATH`, you will probably see the following error when running the `sdf2usd` executable:
+```bash
+sdf2usd: error while loading shared libraries: libusd_usd.so: cannot open shared object file: No such file or directory
+```
+The typical USD library path is `<usd_installation_path>/lib`.
+So, if you installed USD at `/usr/local/USD`, the following command on Linux properly updates the `LD_LIBRARY_PATH` environment variable:
+```bash
+export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/USD/lib
+```
+
+Another thing to note if building with colcon is that after sourcing the workspace with sdformat,
+the `sdf2usd` executable can be run without having to go to the `sdformat/build/bin` directory.
+So, instead of going to that directory and running `./sdf2usd ...`, you should be able to run `sdf2usd ...` from anywhere.

test/test_utils.hh

@@ -18,7 +18,10 @@
 #define SDF_TEST_UTILS_HH_
 
 #include <ostream>
+#include <string>
+
 #include "sdf/Console.hh"
+#include "sdf/Root.hh"
 
 namespace sdf
 {
@@ -104,6 +107,25 @@ class RedirectConsoleStream
   private: sdf::Console::ConsoleStream oldStream;
 };
 
+/// \brief Load an SDF file into a sdf::Root object
+/// \param[in] _fileName The name of the file to load
+/// \param[in] _root The sdf::Root object to load the file into
+/// \return True if a file named _fileName was successfully loaded into
+/// _root. False otherwise
+bool LoadSdfFile(const std::string &_fileName, sdf::Root &_root)
+{
+  auto errors = _root.Load(_fileName);
+  if (!errors.empty())
+  {
+    std::cerr << "Errors encountered:\n";
+    for (const auto &e : errors)
+      std::cerr << e << "\n";
+    return false;
+  }
+
+  return true;
+}
+
 } // namespace testing
 } // namespace sdf
 

usd/include/sdf/CMakeLists.txt

@@ -0,0 +1 @@
+ign_install_all_headers(COMPONENT usd)

usd/include/sdf/usd/World.hh

@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2022 Open Source Robotics Foundation
+ *
+ * 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
+ *
+ *     http://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.
+ *
+*/
+
+#ifndef SDF_USD_WORLD_HH_
+#define SDF_USD_WORLD_HH_
+
+#include <string>
+
+#pragma push_macro ("__DEPRECATED")
+#undef __DEPRECATED
+#include <pxr/usd/usd/stage.h>
+#pragma pop_macro ("__DEPRECATED")
+
+#include "sdf/config.hh"
+#include "sdf/system_util.hh"
+#include "sdf/World.hh"
+
+namespace sdf
+{
+  // Inline bracke to help doxygen filtering.
+  inline namespace SDF_VERSION_NAMESPACE {
+  //
+  namespace usd
+  {
+    /// \brief Parse an SDF world into a USD stage.
+    /// \param[in] _world The SDF world to parse.
+    /// \param[in] _stage The stage that should contain the USD representation
+    /// of _world. It must be initialized first
+    /// \param[in] _path The USD path of the parsed world in _stage, which must be
+    /// a valid USD path.
+    /// \return Errors, which is a vector of Error objects. Each Error includes
+    /// an error code and message. An empty vector indicates no error.
+    sdf::Errors SDFORMAT_VISIBLE ParseSdfWorld(const sdf::World &_world,
+        pxr::UsdStageRefPtr &_stage, const std::string &_path);
+  }
+  }
+}
+
+#endif

usd/src/CMakeLists.txt

@@ -0,0 +1,26 @@
+# Collect source files into the "sources" variable and unit test files into the
+# "gtest_sources" variable.
+ign_get_libsources_and_unittests(sources gtest_sources)
+
+ign_add_component(usd SOURCES ${sources} GET_TARGET_NAME usd_target)
+
+target_include_directories(${usd_target}
+  PUBLIC
+    ${PXR_INCLUDE_DIRS}
+)
+
+target_link_libraries(${usd_target}
+  PUBLIC
+    ignition-common${IGN_COMMON_VER}::ignition-common${IGN_COMMON_VER}
+    ${PXR_LIBRARIES}
+)
+
+# Build the unit tests
+ign_build_tests(
+  TYPE UNIT
+  SOURCES ${gtest_sources}
+  LIB_DEPS ${usd_target} ignition-cmake${IGN_CMAKE_VER}::utilities
+  INCLUDE_DIRS ${PROJECT_SOURCE_DIR}/test
+)
+
+add_subdirectory(cmd)

usd/src/World.cc

@@ -0,0 +1,73 @@
+/*
+ * Copyright (C) 2022 Open Source Robotics Foundation
+ *
+ * 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
+ *
+ *     http://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.
+ *
+*/
+
+#include "sdf/usd/World.hh"
+
+#include <iostream>
+#include <string>
+
+#include <pxr/base/gf/vec3f.h>
+#include <pxr/usd/sdf/path.h>
+#include <pxr/usd/usd/prim.h>
+#pragma push_macro ("__DEPRECATED")
+#undef __DEPRECATED
+#include <pxr/usd/usd/stage.h>
+#pragma pop_macro ("__DEPRECATED")
+#include <pxr/usd/usdGeom/tokens.h>
+#include <pxr/usd/usdPhysics/scene.h>
+
+#include "sdf/World.hh"
+
+namespace sdf
+{
+// Inline bracke to help doxygen filtering.
+inline namespace SDF_VERSION_NAMESPACE {
+//
+namespace usd
+{
+  sdf::Errors ParseSdfWorld(const sdf::World &_world, pxr::UsdStageRefPtr &_stage,
+      const std::string &_path)
+  {
+    sdf::Errors errors;
+    _stage->SetMetadata(pxr::UsdGeomTokens->upAxis, pxr::UsdGeomTokens->z);
+    _stage->SetEndTimeCode(100);
+    _stage->SetMetadata(pxr::TfToken("metersPerUnit"), 1.0);
+    _stage->SetStartTimeCode(0);
+    _stage->SetTimeCodesPerSecond(24);
+
+    const pxr::SdfPath worldPrimPath(_path);
+    auto usdWorldPrim = _stage->DefinePrim(worldPrimPath);
+
+    auto usdPhysics = pxr::UsdPhysicsScene::Define(_stage,
+        pxr::SdfPath(_path + "/physics"));
+    const auto &sdfWorldGravity = _world.Gravity();
+    const auto normalizedGravity = sdfWorldGravity.Normalized();
+    usdPhysics.CreateGravityDirectionAttr().Set(pxr::GfVec3f(
+          normalizedGravity.X(), normalizedGravity.Y(), normalizedGravity.Z()));
+    usdPhysics.CreateGravityMagnitudeAttr().Set(
+        static_cast<float>(sdfWorldGravity.Length()));
+
+    // TODO(ahcorde) Add parser
+    std::cerr << "Parser for a sdf world only parses physics information at "
+              << "the moment. Models and lights that are children of the world "
+              << "are currently being ignored.\n";
+
+    return errors;
+  }
+}
+}
+}