Raytracing was merged into Dev-Rendering!

[TommyBear]

Thanks Tommy, what about GI?

Everything we are discussing here is based on DXR (DirectX Raytracing API). UE4 raytracing is based on this, with an alternate path using Vulkan(with card OEM extensions). Therefore, if your card does not support the Ray Tracing features of DXR, all this stuff will not work.

I know not everyone is made of money or can afford new HW, but Nvidia's RTX based HW is now selling for as little as $349 US for the 2060, all the way to $1200 US for the 2080 TI. So you have some options if you want to explore ray tracing with UE4.

It makes little to no sense have RT available as a custom CPU/GPU solution for UE4, considering the HW will be widespread within a year (and will be cheaper and faster). Best to buy the HW or wait to see if your GPU vendor supports it as a patch to existing drivers somehow.

Tommy.

[Leo Rakes]

I have found this video at Youtube, shows some translucency material:

Translucency looks great, as we saw in SpeedLight DEMO. If Mask and Foliage and HISM can be supported, Landscape can be supported, then we can start to use DXR technology in 4.22.

[Antidamage]

That's not raytraced translucency. It's a (still very nice) shader sampling a cube render texture: https://i.imgur.com/kvHlUyb.jpg

The real benefit of raytraced translucency is that it'll wipe the slate clean of all of the existing buggy UE translucency stuff. It should look pretty close to what we saw above though.

[ITA333]

I try activate raytraced translucency , with console command, but every time crash system.
(r.RayTracing.Translucency 1).

[kurylo3d]

Aye, agree that baking is practical, but I don't know how the tech will do this faster or better... if someone says to me the once you have previewed in real-time and is satisfied and with a click of a button you will get a fast baked scene with the preview settings and will take 1 min, then that's awesome, but surely for the engine I didn't see this being commented by Epic's staff or that (and anything else) being on road map... would be nice to know thou.

they have rtx videos online during the reveal of the card of lightmap baking happen in unreal engine 4 in real time when u stop moving the light

[NilsonLima]

they have rtx videos online during the reveal of the card of lightmap baking happen in unreal engine 4 in real time when u stop moving the light

Please, feed us with a link! Thanks!

[kurylo3d]

Please, feed us with a link! Thanks!

https://youtu.be/tjf-1BxpR9c?t=411

[NilsonLima]

https://youtu.be/tjf-1BxpR9c?t=411

Hmm. but that is not the implementation we are discussing here. I see that it is running on NVidia's branch for GameWorks... I gotta check that, but I don't think it is released already, there is a long time I don't mess with GameWorks.

Btw, at that specific timeline, we can see several black artifacts in the distant background scene, maybe those are result of a lack of tweaking in the scene, and probably is, but so far I am really looking have some info from Epic staff about the implementation we will use from Epic instead of that one with GameWorks.

Maybe someone watching this thread and messing with GameWorks could confirm this is released to the public already?

Thanks for the link!

[Manoel.Neto]

Aye, agree that baking is practical, but I don't know how the tech will do this faster or better... if someone says to me the once you have previewed in real-time and is satisfied and with a click of a button you will get a fast baked scene with the preview settings and will take 1 min, then that's awesome, but surely for the engine I didn't see this being commented by Epic's staff or that (and anything else) being on road map... would be nice to know thou.

Lightmass baking is pretty much all about tracing a huge amount of rays. The RTX cards have hardware accelerated raytracing. Obviously, a Lightmass implementation using DXR would be, at the very least, 100x faster.

[Antidamage]

Firstly, you wouldn't want RTX results going into a lightmap. They're nice, but at the same time they're not that good and are still just a general estimate of how real light would look. Their entire upsell is in the "realtime" part. So that means you have to run a better looking offline renderer on the GPU. Right now that means path tracing.

For a while I was working on a GPU accelerated path-traced lightmass replacement for UE. Not only was progress difficult, the results weren't all that great unless you spent a week rendering your lighting. That product made it into Unity in a different form where I believe it's still just a viewport renderer.

People underestimate just how much work is done when you bake the lighting for a level. It's hundreds of thousands of times more work than simply raytracing a scene to a viewport, realtime or not. To get a good result from path tracing you either spend more time building the lightmap (even with GPU acceleration) than you ever world running lightmass, or you rely on a denoiser, something that has really only just appeared on the scene. And the denoiser is part of why RTX results aren't worth pushing into an offline lightmap. In the next couple of graphics card generations realtime graphics like this are very quickly going to reach a point where the denoiser is both obvious and the results are not good enough. It is a temporary solution.

Hopefully RTX gives Epic enough tools to write a CUDA version of lightmass, but I'd wait and see what they say about that as it could easily go either way.

[Antidamage]

Hmm. but that is not the implementation we are discussing here. I see that it is running on NVidia's branch for GameWorks... I gotta check that, but I don't think it is released already, there is a long time I don't mess with GameWorks.

Btw, at that specific timeline, we can see several black artifacts in the distant background scene, maybe those are result of a lack of tweaking in the scene, and probably is, but so far I am really looking have some info from Epic staff about the implementation we will use from Epic instead of that one with GameWorks.

Maybe someone watching this thread and messing with GameWorks could confirm this is released to the public already?

Thanks for the link!

That was probably shadow caching.

[Nocturness]

when will come
https://www.youtube.com/watch?v=MRZiya1DW3c

[overfuze]

Here are the tests with reflection multibounce, its fast but visually really dissapointing (for now), the reflections only seem to reflect the reflections and the indirect baked lighting (from skylight, etc), no dynamic shadows or AO at all...

https://cdn.discordapp.com/attachmen...36/unknown.png

https://cdn.discordapp.com/attachmen...43/unknown.png

[Frenetic Pony]

Firstly, you wouldn't want RTX results going into a lightmap. They're nice, but at the same time they're not that good and are still just a general estimate of how real light would look. Their entire upsell is in the "realtime" part. So that means you have to run a better looking offline renderer on the GPU. Right now that means path tracing.

For a while I was working on a GPU accelerated path-traced lightmass replacement for UE. Not only was progress difficult, the results weren't all that great unless you spent a week rendering your lighting. That product made it into Unity in a different form where I believe it's still just a viewport renderer.

People underestimate just how much work is done when you bake the lighting for a level. It's hundreds of thousands of times more work than simply raytracing a scene to a viewport, realtime or not. To get a good result from path tracing you either spend more time building the lightmap (even with GPU acceleration) than you ever world running lightmass, or you rely on a denoiser, something that has really only just appeared on the scene. And the denoiser is part of why RTX results aren't worth pushing into an offline lightmap. In the next couple of graphics card generations realtime graphics like this are very quickly going to reach a point where the denoiser is both obvious and the results are not good enough. It is a temporary solution.

Hopefully RTX gives Epic enough tools to write a CUDA version of lightmass, but I'd wait and see what they say about that as it could easily go either way.

Well it won't be on CUDA, because that's Nvidia specific. Nor will the new lightmapper be RTX specific, instead it appears to be some accelerated raytracer that doesn't rely on final gather (one hopes).

I would expect that, at some point and quite possibly right out the gate, the lightmapper will get DXR support, possibly for previews, baking, or both. RTX is, again, Nvidia's buzzword for Microsoft's DXR standard. The DXR standard does however bring many nicities for raytracing, and RTX's fixed function BHV block will probably be supported as well.

[Nocturness]

another test.
i think denoiser works buggy now. sky gi sample and bounce values(evalsky on) do not make a significant difference when denoiser is on.