Move to Ubuntu 22.04, build shared libraries by default, simplified (smaller) python package. (#7516)

- This PR simplifies how Open3D is built and packaged: libOpen3D is now a shared library by default, and Python ships a single open3d.pybind DLL instead of separate cpu/cuda variants. __init__.py is much simplified.
- BUILD_SHARED_LIBS now defaults to ON
- Device strings accept a bare type name (e.g. Device("cuda"), "cpu"), defaulting id to 0, alongside the existing "CUDA:0" form.
- 2 stage build: build-lib -> package -> build-wheel. Reduces total builds.

Author: ssheorey

.github/workflows/README.md

@@ -134,7 +134,7 @@ either due to lack of resources or GPU quota exhaustion.
 
 The custom VM image has NVIDIA drivers, `nvidia-container-toolkit` and `docker`
 installed. It contains today's date in the name and the image family is set to
-`ubuntu-os-docker-gpu-2004-lts`. The latest image from this family is
+`ubuntu-os-docker-gpu-2204-lts`. The latest image from this family is
 used for running CI.
 
 #### Step 3: GitHub

.github/workflows/macos.yml

@@ -26,7 +26,7 @@ env:
   BUILD_CUDA_MODULE: OFF
 
 jobs:
-  MacOS:
+  build-lib:
     permissions:
       contents: write  # upload
       id-token: write
@@ -66,19 +66,30 @@ jobs:
 
       - name: Install dependencies
         run: |
-          brew install ccache glslang spirv-cross
-          # Fix gfortran not found issue. 
-          brew install gcc
+          brew install ccache glslang spirv-cross gcc
           ln -s $(brew --prefix gcc)/bin/gfortran-* /usr/local/bin/gfortran
 
           ccache -M 2G  # See .github/workflows/readme.md for ccache strategy.
       - name: Config and build
         run: |
           PATH=/usr/local/var/homebrew/linked/ccache/libexec:$PATH
           ccache -s
+          export BUILD_PYTHON_MODULE=OFF
           ./util/run_ci.sh
           DEVEL_PKG_NAME="$(basename build/package/open3d-devel-*.tar.xz)"
           echo "DEVEL_PKG_NAME=$DEVEL_PKG_NAME" >> $GITHUB_ENV
+          
+          # Compress build directory for reuse (exclude some large potentially unnecessary files if needed)
+          # We need 'build' directory.
+          tar -caf build.tar.xz build
+
+      - name: Upload build artifact
+        if: ${{ matrix.CONFIG == 'OFF' }}
+        uses: actions/upload-artifact@v4
+        with:
+          name: open3d-build-${{ matrix.os }}
+          path: build.tar.xz
+          retention-days: 1
       - name: Build Open3D viewer app
         if: ${{ env.BUILD_SHARED_LIBS == 'OFF' }}
         run: |
@@ -130,6 +141,7 @@ jobs:
           fi
 
   build-wheel:
+    needs: build-lib
     name: Build wheel
     permissions:
       contents: write  # upload
@@ -172,6 +184,14 @@ jobs:
           ref: main
           path: ${{ env.OPEN3D_ML_ROOT }}
 
+      - name: Download build artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: open3d-build-${{ matrix.os }}
+      
+      - name: Unpack build artifact
+        run: tar -xf build.tar.xz
+
       - name: Setup cache
         uses: actions/cache@v4
         with:
@@ -183,8 +203,7 @@ jobs:
           # Restore any ccache cache entry, if none for
           # ${{ runner.os }}-${{ runner.arch }}-ccache-${{ github.sha }} exists.
           # Common prefix will be used so that ccache can be used across commits.
-          restore-keys: |
-            ${{ runner.os }}-${{ runner.arch }}-ccache
+          restore-keys: ${{ runner.os }}-${{ runner.arch }}-ccache
 
       - name: Set up Python
         uses: actions/setup-python@v5
@@ -202,13 +221,10 @@ jobs:
           source util/ci_utils.sh
           install_python_dependencies
 
-          # Fix macos-14 arm64 runner image issues, see comments in MacOS job.
-          # brew install gcc is required so that `brew --prefix gcc` resolves;
-          brew install gcc
-          ln -s $(brew --prefix gcc)/bin/gfortran-* /usr/local/bin/gfortran
-
-          brew install ccache glslang spirv-cross 
+          brew install ccache glslang spirv-cross gcc
           ccache -M 2G  # See .github/workflows/readme.md for ccache strategy.
+          # Fix gfortran not found issue
+          ln -s $(brew --prefix gcc)/bin/gfortran-* /usr/local/bin/gfortran
 
       - name: Config and build wheel
         run: |

.github/workflows/ubuntu-cuda.yml

@@ -57,14 +57,13 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - CI_CONFIG: 2-jammy
-          - CI_CONFIG: 3-ml-shared-jammy
-          - CI_CONFIG: 5-ml-noble
+          - CI_CONFIG: 2-noble
+          - CI_CONFIG: 3-ml-shared-noble
     env:
       # Export everything from matrix to be easily used.
       # Docker tag and ccache names must be consistent with docker_build.sh
       CI_CONFIG          : ${{ matrix.CI_CONFIG }}
-      BUILD_PACKAGE      : ${{ contains(fromJson('["3-ml-shared-jammy"]'), matrix.CI_CONFIG) }}
+      BUILD_PACKAGE      : ${{ contains(fromJson('["3-ml-shared-noble"]'), matrix.CI_CONFIG) }}
       GCE_INSTANCE_PREFIX: open3d-ci-${{ matrix.CI_CONFIG }}
       DOCKER_TAG         : open3d-ci:${{ matrix.CI_CONFIG }}
       CCACHE_TAR_NAME    : open3d-ci-${{ matrix.CI_CONFIG }}

.github/workflows/ubuntu-openblas.yml

@@ -34,13 +34,48 @@ jobs:
       - name: Docker test
         run: docker/docker_test.sh openblas-amd64-py312-dev
 
-  openblas-arm64:
+  build-lib-arm64:
+    name: Build Lib ARM64
     permissions:
       contents: write  # Release upload
       id-token: write
       attestations: write
       artifact-metadata: write
     runs-on: ubuntu-24.04-arm   # latest
+    env:
+      DEVELOPER_BUILD: 'ON'
+      OPEN3D_CPU_RENDERING: true
+    steps:
+      - name: Checkout source code
+        uses: actions/checkout@v4
+      - name: Maximize build space
+        run: |
+          source util/ci_utils.sh
+          maximize_ubuntu_github_actions_build_space
+
+      - name: Docker build lib
+        run: |
+          # Use py310 as dummy
+          docker/docker_build.sh openblas-arm64-py310-dev build-lib
+          # Image name open3d-ci:openblas-arm64-py310-dev (check valid tag in script)
+          docker tag open3d-ci:openblas-arm64-py310-dev open3d-lib-arm64:latest
+          docker save open3d-lib-arm64:latest | gzip > open3d-lib-arm64.tar.gz
+
+      - name: Upload Lib Image
+        uses: actions/upload-artifact@v4
+        with:
+          name: open3d-lib-arm64
+          path: open3d-lib-arm64.tar.gz
+          retention-days: 1
+
+  build-wheel-arm64:
+    name: Build Wheel ARM64
+    permissions:
+      contents: write  # Release upload
+      id-token: write
+      attestations: write
+    runs-on: ubuntu-24.04-arm
+    needs: build-lib-arm64
     strategy:
       fail-fast: false
       matrix:
@@ -68,6 +103,15 @@ jobs:
           source util/ci_utils.sh
           maximize_ubuntu_github_actions_build_space
 
+      - name: Download Lib Image
+        uses: actions/download-artifact@v4
+        with:
+          name: open3d-lib-arm64
+          path: .
+      
+      - name: Load Lib Image
+        run: docker load -i open3d-lib-arm64.tar.gz  # Restore open3d-lib-arm64:latest
+
       - name: Compute Docker tag for this matrix entry
         run: |
           # Strip the dot: 3.12 ➜ 312, 3.14 ➜ 314 …
@@ -78,6 +122,7 @@ jobs:
 
       - name: Docker build
         run: |
+          export BASE_IMAGE=open3d-lib-arm64:latest
           docker/docker_build.sh "${DOCKER_TAG}"
           shopt -s failglob
           PIP_PKG_NAME="$(basename ${GITHUB_WORKSPACE}/open3d-[0-9]*.whl)"

.github/workflows/ubuntu-sycl.yml

@@ -23,7 +23,8 @@ env:
   DEVELOPER_BUILD: ${{ github.event.inputs.developer_build || 'ON' }}
 
 jobs:
-  ubuntu-sycl:
+  build-lib:
+    name: Build Lib
     permissions:
       contents: write  # Release upload
       id-token: write
@@ -41,39 +42,37 @@ jobs:
         run: |
           source util/ci_utils.sh
           maximize_ubuntu_github_actions_build_space
-      - name: Docker build
+      - name: Docker build lib
         run: |
+          # Use py310 as dummy
           if [ "${{ matrix.BUILD_SHARED_LIBS }}" = "ON" ]; then
-            docker/docker_build.sh sycl-shared
+            docker/docker_build.sh sycl-shared build-lib
+            docker tag open3d-ci:sycl-shared open3d-lib-sycl-shared:latest
+            docker save open3d-lib-sycl-shared:latest -o open3d-lib-sycl-shared.tar
+            xz open3d-lib-sycl-shared.tar
+            ls -lhs open3d-lib-sycl-shared.tar.xz
           else
-            docker/docker_build.sh sycl-static
-          fi
-      - name: Docker test
-        run: |
-          du -hs $PWD
-          if [ "${{ matrix.BUILD_SHARED_LIBS }}" = "ON" ]; then
-            docker/docker_test.sh sycl-shared
-          else
-            docker/docker_test.sh sycl-static
+            docker/docker_build.sh sycl-static build-lib
+            # Static build usually doesn't produce wheels or shared libs for python
+            # But we might need artifacts. For now keep simple.
           fi
 
-      - name: Generate artifact attestation
+      - name: Upload Lib Image
         if: ${{ matrix.BUILD_SHARED_LIBS == 'ON' }}
-        uses: actions/attest@v4
+        uses: actions/upload-artifact@v4
         with:
-          subject-path: |
-            ${{ github.workspace }}/open3d*.whl
-            ${{ github.workspace }}/open3d-devel-*.tar.xz
+          name: open3d-lib-sycl-shared
+          path: open3d-lib-sycl-shared.tar.xz
+          retention-days: 1
 
-      - name: Upload Python wheel and C++ binary package to GitHub artifacts
+      - name: Upload C++ binary package to GitHub artifacts
         if: ${{ matrix.BUILD_SHARED_LIBS == 'ON' }}
         uses: actions/upload-artifact@v4
         with:
-          name: open3d-sycl-linux-wheel-and-binary
-          path: |
-            open3d*.whl
-            open3d-devel-*.tar.xz
+          name: open3d-devel-sycl
+          path: open3d-devel-*.tar.xz
           if-no-files-found: error
+
       - name: Update devel release
         if: ${{ github.ref == 'refs/heads/main' && matrix.BUILD_SHARED_LIBS == 'ON' }}
         env:
@@ -97,3 +96,73 @@ jobs:
         if: ${{ github.ref == 'refs/heads/main' }}
         run: |
           gsutil cp ${GITHUB_WORKSPACE}/open3d-ci-sycl.tar.gz gs://open3d-ci-cache/ || true
+
+  build-wheel:
+    name: Build Wheel
+    permissions:
+      contents: write  # Release upload
+      id-token: write
+      attestations: write
+      artifact-metadata: write
+    runs-on: ubuntu-latest
+    needs: build-lib
+    strategy:
+      fail-fast: false
+      matrix:
+        python_version: ['3.10', '3.11', '3.12', '3.13']
+        is_main:
+          - ${{ github.ref == 'refs/heads/main' }}
+        exclude:
+          - is_main: false
+            python_version: '3.10'
+          - is_main: false
+            python_version: '3.11'
+          - is_main: false
+            python_version: '3.12'
+    env:
+      PYTHON_VERSION: ${{ matrix.python_version }}
+    steps:
+      - name: Checkout source code
+        uses: actions/checkout@v4
+      - name: Maximize build space
+        run: |
+          source util/ci_utils.sh
+          maximize_ubuntu_github_actions_build_space
+
+      - name: Download Lib Image
+        uses: actions/download-artifact@v4
+        with:
+          name: open3d-lib-sycl-shared
+          path: .
+      
+      - name: Load Lib Image
+        run: docker load -i open3d-lib-sycl-shared.tar.xz 
+
+      - name: Docker build
+        run: |
+          export BASE_IMAGE=open3d-lib-sycl-shared:latest
+          
+          # We execute docker buildscript with python version argument.
+          docker/docker_build.sh sycl-shared py${{ matrix.python_version }}
+
+      - name: Generate artifact attestation
+        uses: actions/attest@v4
+        with:
+          subject-path: |
+            ${{ github.workspace }}/open3d*.whl
+
+      - name: Upload wheel to GitHub artifacts
+        uses: actions/upload-artifact@v4
+        with:
+          name: open3d-sycl-wheel-py${{ matrix.python_version }}
+          path: open3d*.whl
+          if-no-files-found: error
+
+      - name: Update devel release
+        if: ${{ github.ref == 'refs/heads/main' }}
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          gh release upload main-devel open3d-*.whl --clobber
+          gh release view main-devel
+