Simplify cmake cuda setup (#201)

This PR streamlines the CMake CUDA setup by:

* Disabling CUDA builds by default.
* Set CUDA architecture to native if not specified. Avoid poking into the internal of the Scalable CCD.
* Bump cmake minimum version to 3.24 to support `CMAKE_CUDA_ARCHITECTURES="native"`

Since CUDA code is sensitive to environment changes (i.e., IPC fails to build on CUDA 13.0+), enabling it implicitly can create surprises for its consumer. As a library, the CUDA build should be guarded behind a CMake option.

Also, ipc-toolkit currently inherits the CUDA architecture from Scalable CCD, which defaults to `"native"` if not defined. Instead, we should handle this explicitly.

Author: iiiian

.github/workflows/cuda.yml

@@ -70,6 +70,7 @@ jobs:
           cd build
           cmake .. \
             -DIPC_TOOLKIT_WITH_CUDA=ON \
+            -DCMAKE_CUDA_ARCHITECTURES=75 \
             -DSCALABLE_CCD_CUDA_ARCHITECTURES=75 \
             -DIPC_TOOLKIT_BUILD_TESTS=ON \
             -DIPC_TOOLKIT_BUILD_PYTHON=ON \

CMakeLists.txt

@@ -7,7 +7,7 @@ else()
 endif()
 
 # Check required CMake version
-set(REQUIRED_CMAKE_VERSION "3.18.0")
+set(REQUIRED_CMAKE_VERSION "3.24.0")
 if(IPC_TOOLKIT_TOPLEVEL_PROJECT)
   cmake_minimum_required(VERSION ${REQUIRED_CMAKE_VERSION})
 else()
@@ -64,9 +64,6 @@ project(IPCToolkit
         LANGUAGES CXX
         VERSION "1.5.0")
 
-include(CheckLanguage)
-check_language(CUDA)
-
 if(IPC_TOOLKIT_TOPLEVEL_PROJECT)
   option(IPC_TOOLKIT_BUILD_TESTS  "Build unit-tests"       ON)
   option(IPC_TOOLKIT_BUILD_PYTHON "Build Python bindings" OFF)
@@ -77,11 +74,7 @@ else()
   set(IPC_TOOLKIT_BUILD_PYTHON OFF CACHE BOOL "Build Python bindings" FORCE)
 endif()
 
-if(CMAKE_CUDA_COMPILER)
-  option(IPC_TOOLKIT_WITH_CUDA "Enable CUDA CCD" ON)
-else()
-  option(IPC_TOOLKIT_WITH_CUDA "Enable CUDA CCD" OFF)
-endif()
+option(IPC_TOOLKIT_WITH_CUDA                  "Enable CUDA CCD"                               OFF)
 option(IPC_TOOLKIT_WITH_RATIONAL_INTERSECTION "Use rational edge-triangle intersection check" OFF)
 option(IPC_TOOLKIT_WITH_ROBIN_MAP             "Use Tessil's robin-map rather than std maps"    ON)
 option(IPC_TOOLKIT_WITH_ABSEIL                "Use Abseil's hash functions"                    ON)
@@ -245,9 +238,14 @@ target_compile_features(ipc_toolkit PUBLIC cxx_std_17)
 ################################################################################
 
 if(IPC_TOOLKIT_WITH_CUDA)
-  if(NOT CMAKE_CUDA_COMPILER)
-    message(FATAL_ERROR "CUDA support requested but no CUDA compiler found!")
+  # If CMAKE_CUDA_ARCHITECTURES was not specified, set it to native.
+  if(DEFINED CMAKE_CUDA_ARCHITECTURES)
+    message(STATUS "CMAKE_CUDA_ARCHITECTURES was specified, skipping auto-detection")
+  else()
+    message(STATUS "CMAKE_CUDA_ARCHITECTURES was not specified, set it to native")
+    set(CMAKE_CUDA_ARCHITECTURES "native")
   endif()
+  message(STATUS "Targeting CUDA_ARCHITECTURES \"${CMAKE_CUDA_ARCHITECTURES}\"")
 
   # Enable CUDA support
   enable_language(CUDA)
@@ -256,10 +254,6 @@ if(IPC_TOOLKIT_WITH_CUDA)
   # library to be built with -dc as the member functions could be called by
   # other libraries and executables.
   set_target_properties(ipc_toolkit PROPERTIES CUDA_SEPARABLE_COMPILATION ON)
-
-  # Use the same CUDA architectures Scalable CCD
-  get_target_property(CMAKE_CUDA_ARCHITECTURES scalable_ccd CUDA_ARCHITECTURES)
-  set_target_properties(ipc_toolkit PROPERTIES CUDA_ARCHITECTURES "${CMAKE_CUDA_ARCHITECTURES}")
 endif()
 
 ################################################################################
@@ -311,4 +305,4 @@ if (CMAKE_GENERATOR STREQUAL "Xcode")
   if(IPC_TOOLKIT_BUILD_PYTHON)
     set_target_properties(ipctk PROPERTIES XCODE_GENERATE_SCHEME ON)
   endif()
-endif()
+endif()

CMakePresets.json

@@ -2,7 +2,7 @@
   "version": 3,
   "cmakeMinimumRequired": {
     "major": 3,
-    "minor": 18
+    "minor": 24
   },
   "configurePresets": [{
       "name": "release",
@@ -166,4 +166,4 @@
       }
     }
   ]
-}
+}

README.md

@@ -16,19 +16,19 @@ IPC Toolkit is a set of reusable functions to integrate Incremental Potential Co
 
 ### Features
 
-* IPC barrier function and its derivatives and adaptive barrier stiffness algorithm
+* IPC barrier function and its derivatives, and adaptive barrier stiffness algorithm
 * Broad- and narrow-phase continuous collision detection (CCD) of linear and nonlinear trajectories
 * Distance computation and derivatives between edges in 2D and triangles in 3D
 * Distance barrier potential and its derivatives
 * Smooth and lagged dissipative friction potential and its derivatives
 
 ### Limitations
 
-This is not a full simulation library. As such it does not include any physics or solvers. For a full simulation implementation, we recommend [PolyFEM](https://polyfem.github.io/) (a finite element library) or [Rigid IPC](https://github.com/ipc-sim/rigid-ipc) (rigid-body dynamics) both of which utilize the IPC Toolkit.
+This is not a full simulation library. As such, it does not include any physics or solvers. For a full simulation implementation, we recommend [PolyFEM](https://polyfem.github.io/) (a finite element library) or [Rigid IPC](https://github.com/ipc-sim/rigid-ipc) (rigid-body dynamics), both of which utilize the IPC Toolkit.
 
 ## Build
 
-Instruction for building and including the IPC Toolkit in your CMake project can be found on the website [here](https://ipctk.xyz/build.html).
+Instructions for building and including the IPC Toolkit in your CMake project can be found on the website [here](https://ipctk.xyz/build/c++.html).
 
 ### Dependencies
 
@@ -42,7 +42,7 @@ A full list of dependencies can be found on the [dependencies page](https://ipct
 
 We provide Python bindings for functions in the toolkit using [pybind11](https://github.com/pybind/pybind11).
 
-For more information see the [Python documentation](https://ipctk.xyz/python.html).
+For more information, see the [Python documentation](https://ipctk.xyz/python.html).
 
 ## Usage
 
@@ -61,7 +61,7 @@ Simply fork this repository and make a Pull Request! We would appreciate:
 
 ## Citation
 
-IPC Toolkit is created and maintained by academics: citations let us know our work is having impact! Please cite the IPC Toolkit or otherwise give a shout-out if and when it contributes to published works.
+The IPC Toolkit is created and maintained by academics: citations let us know our work is having an impact! Please cite the IPC Toolkit or otherwise give a shout-out if and when it contributes to published works.
 
 ```bibtex
 @software{ipc_toolkit,
@@ -93,4 +93,4 @@ This project is licensed under the MIT License.
 
 You are free to use, modify, and distribute this code in your projects, even commercial ones, as long as you include the original copyright and license notice. A copy of the full license text can be found in the <a href="https://github.com/ipc-sim/ipc-toolkit/blob/main/LICENSE"><code>LICENSE</code></a> file.
 
-If you use this code in a product you distribute to others, you are required to **include a copy of the original copyright and license notice**. This is typically done in the product's documentation, an "About" or "Third-Party Licenses" section, or in a clear open-source software statement.
+If you use this code in a product you distribute to others, you are required to **include a copy of the original copyright and license notice**. This is typically done in the product's documentation, an "About" or "Third-Party Licenses" section, or in a clear open-source software statement.

docs/source/build/c++.rst

@@ -53,6 +53,8 @@ You can build the IPC Toolkit using CMake as you would any other CMake project.
 
 This will build the IPC Toolkit and all of its dependencies. The ``IPC_TOOLKIT_BUILD_TESTS`` option enables building the unit tests, and the ``IPC_TOOLKIT_BUILD_PYTHON`` option enables building the Python bindings.
 
+CUDA support is disabled by default. Enable it by setting CMake option ``IPC_TOOLKIT_WITH_CUDA`` to ON.
+
 .. warning::
    Installing the IPC Toolkit using the ``make install`` has not been tested and is not recommended. The IPC Toolkit is designed to be used as a submodule in your project, and as such does not have a proper install target.
 
@@ -61,4 +63,4 @@ Dependencies
 
 **All required dependencies are downloaded through CMake** depending on the build options, and are built automatically when you build the IPC Toolkit. You do not need to install them separately.
 
-A full list of dependencies can be found on the `dependencies page <https://ipctk.xyz/dependencies.html>`_.
+A full list of dependencies can be found on the `dependencies page <https://ipctk.xyz/dependencies.html>`_.

pyproject.toml

@@ -3,7 +3,7 @@ requires = [
     "setuptools>=42",
     "wheel",
     "ninja",
-    # "cmake>=3.14",
+    # "cmake>=3.24",
 ]
 build-backend = "setuptools.build_meta"