Raytracing was merged into Dev-Rendering!

I was just checking Dev-Rendering, as I do regularly, and I was surprised!

Raytracing was merged! If I’d have a RTX GPU I’d test it, but I don’t have one.

Here’s the main commit: https://github.com/EpicGames/UnrealE…b3591e5fc2fe6c

It seems Ray-Traced reflections (RayTracingReflections.usf) and Ray-Traced Ambient Occlusion (RayTracingAmbientOcclusionRGS.usf) are the two most interesting things that are added. Especially Ray-Traced Ambient Occlusion I find very interesting, looking very much forward to supporting that in my game.

Hello, I have a RTX graphics card. I downloaded and built the latest version of Unreal engine branch. The version number of the engine has been changed to 4.22.0, but I haven’t found anything related to RTX inside?! Is RTX still in the code or is it packaged as a function? Maybe my system version is 1803, so there is no such function?

how could you install 4.22 if it’s not released yet?

GitHub… Engine source in development is shared on GitHub.

mm very interesting I didnt know that , thank you . I HAVE 2070 RTX , will I be able to test RTX with that version ?

You need to build the dev-rendering branch, I assume when you say you “built the latest version of Unreal engine branch” you actually built the master branch, not dev-rendering.

Maybe so? I built the engine in the link you posted, and the version number was 4.22.0 after the build. There were ray tracing commands in the console, but I didn’t find any other relevant options. So what I need to build is the dev-rendering version? Not your link? Then in the dev-rendering branch, can I find the relevant functions of RTX and actually test them? Do you have to add RTX graphics card to 1809 system to run the test? I don’t know the main branch of the engine very well. Thank you for telling me that.

It’s not RTX, it’s DXR

Thank you for your reminder. Maybe we have received too much publicity from NVIDIA to forget the part of DXR. With regard to DXR, may I ask if the DXR we obtained on 4.22 includes complete ray tracing shadows, reflections, AO and GI? Will it even contain DLSS or Ansel RTX? Or will these features be rolled out gradually after 4.22?

  • 1 for that question , Do you prepare full DXR/RTX support Unreal Engine in 4.22 ?
    or in other words when expect FULL raytrace implementation in UE ?
    you have been very good in UE roadmapping , is something changed ?

There are some console variables in place already but Raytracing is still disabled (DynamicRHI.h, line 1128) and there are plenty of empty placeholder interface functions. If you enable raytracing in code, the engine won’t launch anymore.
So no raytracing support in this branch yet.

Listen to this gentleman, you’re indeed able to toy around with… a lot of console variable as well as ticking a ‘raytracing’ box in project’s config ‘rendering’ tab ( after ticking some 'skin cache… ’ box aswell).

If you check DynamicRHI.h as stated by Snafuh you’ll notice a large commented piece of code #WITH_RAYTRACING featuring a lot of empty RHI hooks.

I tried to build a branch of DEV_Rendern and turned on the ray tracing variable in the configuration file (its default property seems to be read-only and can only be modified in the configuration), but back in the engine, nothing changed. All light sources and post-processing settings have no relevant options. Even though RAYTRACING has been set to 1 in the console variables, they still do not start any relevant options and effects of ray tracing. Do they seem to be invalid? I’m sure I’m using RTX 2080TI + WIN 10 1809, which shouldn’t be a problem, but in the branch of DEV_Rendern, ray tracing still can’t be started effectively. Maybe they haven’t really been added to the engine?

There are a few things you need to do to enable DXR preview support:

  • Enable skin cache and ray tracing in project settings
  • Use D3D12 by adding -dx12 command line parameter
  • Opt-in to ray tracing preview feature by adding -raytracing command line parameter
  • Obviously, Windows 10 RS5 (October 2018 Update) + NVIDIA RTX card and recent driver

If those criteria are met, then various ray tracing effects will become enabled by default at run-time and new view modes should be available in the editor. Some new console variables will also be available (r.RayTracing.***).

It must be stressed that DXR support is in a very early stage and is not meant for end-users and content-creators. None of the high-level rendering features (reflections, shadows, AO) are production-ready at this point and are under active development.

Current code in dev-rendering is mostly meant for developers to start looking at how ray tracing will be exposed and how to use the low-level API to implement their own custom features.

That is to say, the ray tracing function we currently use in DEV_Rendern is limited to the exploration of API and development, but does not include any substantive functions, such as shadow, AO, GI, etc., which are not included in the rendering branch at all?

There are basic work-in-progress implementations of the high-level features that you mentioned, but none of them are at performance or quality targets. They are actively being developed. There is currently nothing that you can actually use in production (which should be obvious, since we’re talking about a development branch here :)).

does this mean that the DX12 crash on startup is fixed? :rolleyes:

I am personally not aware of any current crashes at startup when using -dx12 flag. So the answer is “probably?” :wink:

Hi !
When Raytracing full support is planned ? 4.22 ?

Can’t say at this point. We are actively working on it, but there is a mountain of work still to do.