Historically, UE has supported hardware tessellation for certain RHIs, however many platforms, including consoles, never supported it. The reasoning behind that decision is that tessellation for any RHI requires regular maintenance, especially when optimizing for performance. In particular, on consoles, we found that the performance limitations of the hardware did not justify the engineering effort of maintaining hardware tessellation and all of the rendering features that rely on it.
It is sometimes important to decide what is worth investing in and not investing in.
With Nanite’s ability to handle really high poly meshes we saw there was less of a need for HW tessellation considering what it is commonly used for.
To better support that path we are right now working on some ways to more conveniently and with higher quality pre-tessellate and displace static meshes.
While some of those use cases can be well covered by Nanite or virtual heightfield terrain it is well understood the power of dynamic displacement mapping. Honestly that was on my mind since the early days of Nanite development as something I wanted to eventually support in Nanite, albeit is no easy task. Research is in progress on that now, ie proprietary Nanite tessellation and displacement mapping. The hope is to create something far superior to what HW tessellation can do. That research is WIP so I can’t really say much more about it or promise anything really (research in inherently risk taking and sometimes fails) but I’ll say I am personally very excited about it and the direction its going.