PhysX Goes Open Source Under BSD License

With some more news after the TITAN RTX launch, NVIDIA has decided to release its physics modeling SDK, PhysX, under an open source BSD license, released on GitHub. This isn’t just the CPU engine, but also the GPU acceleration aspect as well. NVIDIA’s reasoning for this relates to its push for AI, robotics, computer vision, and autonomous vehicles.

It’s strange to think that PhysX is the most widely used physics SDK used in games, despite the fact you rarely see the splash screen for it anymore. PhysX was one of those technologies that NVIDIA bought up many years ago from AGEIA, and then promptly integrated into hardware on its GPUs.

GPU accelerated physics became a bit of a buzz technology for a while, but quickly died off in popularity as it was only used sparingly on select titles. PhysX didn’t disappear though, but was instead relegated to CPU only workloads, much like its competitor, Havok, which was bought by AMD and then sold on to Intel a few years later. The two most popular game engines, Unreal and Unity, both use PhysX under the hood for physics calculations – it’s just that pretty much no games make use of the hardware accelerated version of it anymore.

So with that in mind, it’s not too surprising to see NVIDIA releasing it under an open source license. What will have been a tipping point, is the surge in artificial intelligence and deep learning that NVIDIA has done now for the last couple of years. From its research into robotics training with Isaac, and autonomous vehicles, a simulation of real world interactions is required, i.e. physics calculations.

Since NVIDIA already has a working physics SDK, getting developers to use it and bundle with the various deep learning suites likely required a change of license, not just for NVIDIA, but for its hundreds of partners. There was likely very little in the way of licensing fees remaining, considering PhysX was bundled with popular game engines, so it’s not as if NVIDIA will be losing money with this change of license. The switch to an open source license was likely to alleviate some of the licensing pressures of the rest of the software stack used in AI and deep learning. It now means that third-party researchers can extend the capabilities of PhysX unimpeded too.

Does this mean we’ll see AMD picking up hardware support for PhysX? Not likely, considering how few games made use of the hardware enabled version of it. The software/CPU based version of PhysX has worked fine for years, so we’re unlikely to see any changes in games going forward, especially since 8-core CPUs are now becoming a lot more common.