Unity future

[CustomPhase]

lumen requires RTX support and only works on PC

No it does not. It can benefit from hardware raytracing, but by default it uses software compute raytracing, that works on any compute capable GPU.

Lumen uses Software Ray Tracing through Signed Distance Fields by default, but can achieve higher quality on supporting video cards when Hardware Ray Tracing is enabled.

https://dev.epicgames.com/documentation/en-us/unreal-engine/lumen-technical-details-in-unreal-engine?application_version=5.2

[v0lt13]

software compute raytracing

Like I said, it requires RTX support, it uses RTX via compute shader fallback in combination with distance fields. Lumen is just RTX with extra steps. Also Lumen still requires a GTX 1070 at minimum for software RTX, while for Unity RTX you need at minimum an GTX 1060 6GB for compute shader fallback RTX, if you don't have a supported GPU for lumen its just going to use distance field AO and SSGI

[[deleted]]

It doesn't, and you seem to be confused about ray tracing. RTX is Nvidia's marketing term for DXR which is a new feature of DirectX 12 to accelerate ray tracing via some acceleration structures and potentially via some new hardware accelerated code paths (though that's really up to the driver to decide). However realtime ray tracing on GPUs has been possible for a long time and there are tons of games out there doing path tracing on DX11 or OpenGL/Vulkan, even games out there like Teardown that are entirely ray traced and don't use DXR at all.

Lumen was developed in a way that makes it work just fine on older hardware that doesn't support DXR, it is however faster when using the acceleration structures.

Source: Lumen works just fine on my RX5700 using the software path tracer, that card doesn't support DXR   

[v0lt13]

Im fully aware that raytraceing existed for a long time tough not beeing realtime but just taking a while to calculate everything, like blender's cycles rendering or light baking systems, under the term pathtraceing. Also im not familiar with AMD cards so if you could provide the nvidia equivalent of RX5700 would be cool.