Back at GDC 2019, Unity announced Havok Physics would be coming soon. Yesterday, Havok for Unity was released as a preview package in the Unity Package manager. The Havok physics implementation is built on the DOTS framework therefore you will require Unity 2019.1 for higher to run it.
Details of the Havok preview from the Unity blog:
When we first set out to define what the future of physics would look like with our Data-Oriented Technology Stack (DOTS), we sought a partner that shared the same core concepts and values as us. Through our partnership with Havok, we were able to leverage DOTS to deliver the highly optimized, stateless, entirely C#, and performant Unity Physics. We also knew that some of you would have more complex simulation requirements, needing a stateful physics system. For that reason, we knew Havok would be the perfect solution to integrate into Unity for those high-end simulation needs.
Some of you might be asking, “Ok, but why did you make two systems instead of just one?” We know that our users have a plethora of different use cases, and we wanted to give everyone a choice based on what their needs are. For some, Unity Physics will suffice, while others will want the benefits and enhanced workflows of Havok Physics. Ultimately, there is no right or wrong choice, as we illustrate later in this blog post. You can switch between either solver without having to reauthor all of your content completely.
An obvious question you may have is, why should I choose Havok over the new Unity physics engine? This is explained in the Havok documentation:
Higher simulation performance : Havok Physics is a stateful engine, which makes it more performant than Unity.Physics for scenes with significant numbers of rigid bodies, due to automatic sleeping of inactive rigid bodies and other advanced caching techniques (typically 2x or more faster).
Higher simulation quality : Havok Physics is a mature engine which is robust to many use cases. In particular, it offers stable stacking and a solution for smoothing out contact points when rigid bodies slide quickly over each other (known as "welding").
Deep profiling and debugging of physics simulations using the Havok "Visual Debugger" standalone application (available on Windows only).
You can learn more about the Havok preview in the video below. In addition to an overview of what Havok physics is all about, it also covers the installation process and illustrates how to configure and run the Havok Visual Debugger. The example repository used in the video is available here.