Raytracing was merged into Dev-Rendering!

[Morningcoffee007]

Well that could be the case, still I think it was some sort of complaint about the new technology. Which is fine I guess as long as they understand what they're complaining about.

Yes, it's expensive and it sucks! Just like cars were in 1908. They used to brake down every 2 miles and they were a lot worse then horses right? Thank God most people did not listen to those who complained )

With ray tracing is exactly the same.

[TheJamsh]

DXR functionality is currently limited to DX12 cards that have RT capability. There is no DXR support for legacy GPUs at this time. While there are fallback implementations, they are not DXR main.

Tommy.

Not according to this article at least (whether it's implemented yet is another matter)

"At the base level, DXR will have a full fallback layer for working on existing DirectX 12 hardware."

Lighting is static if its precomputed. Where its stored is just technical detail. Lightmaps, probes, voxels etc.
UE4 currently can use volumetric lightmaps(voxels) for movable objects. This system would just use same voxel based system for everything. So less shader permutations.
You can actually already have this kind of system for UE4 by forcing all objects to use volumetric lightmaps. But baking still require lightmap coordinates to be setuped.

True.. though the Indirect Lighting Cache still lights movable objects too IIRC, I'm fairly sure that's not unique to the newer volumetric lightmaps.

What I really meant is, if static objects have to lookup GI at runtime too - I would guess that would add significant cost.

EDIT: Somehow this ended up in the wrong thread.. err...

[NilsonLima]

"At the base level, DXR will have a full fallback layer for working on existing DirectX 12 hardware."
.

Their repository thou says the code would not be part of final DXR release, but the fallback codebase is there at GitHub for anyone wanting to give support to it.

source: https://github.com/Microsoft/DirectX...racingFallback

so this would fall into the hands of card vendors... which I think won't give support, otherwise they can't sell new cards... wish that wasn't the true

[AE_3DFX]

TheJamsh: thanks for info, if it is true then AMD soon could get driver update to run DXR.

[TheJamsh]

I have no idea how my reply ended up in this thread but.. nevermind.

Their repository thou says the code would not be part of final DXR release, but the fallback codebase is there at GitHub for anyone wanting to give support to it.

I see. That's kind of a shame.. but I guess that's just the price you pay for new tech. Kind of impossible to move forward if you're constantly stuck supporting legacy hardware. DXR still feels like a toy to me at this point.

TheJamsh: thanks for info, if it is true then AMD soon could get driver update to run DXR.

See above. Doesn't seem to be the case.

[AE_3DFX]

TheJamsh: That would be very bad then if AMD wont do DXR support, your thoughts about Nvidia will be only raytracing provider in far future?

[ZacD]

Raytracing standards are still up in the air at this point. It's really only possible to speculate on what we have access to. AMD Radeon Rays is being integrated with Unity, DXR was going to support any DX12 GPU, but apparently removed support for their Fallback Layer for devices without native driver/support. Nvidia may have gutted Ray Tracing support in drivers for non-RTX GPUs. Some of this stuff is speculation/incomplete information. Eventually I'm sure there will be convergence on a single standard, or at least a most popular standard.

[A100KA]

Hello, does any of you know why this problem appears as it adds to the scene point light, spot light..etc .... my GPU is RTX 2070
I will add that I have no problems with Starter Content on the stage.

[Antidamage]

Well that could be the case, still I think it was some sort of complaint about the new technology.

Experimental means the feature has only just been added to Unreal Engine and isn't mature enough for inclusion in distribution builds. Don't impose your own loaded definition on what I wrote.

[OwenWP]

There really isn't much point to maintaining the fallback layer at the API level beyond having a reference implementation for hardware makers to use to validate their drivers (which is what the old DXR preview was), it simply could never be fast enough for realtime use, and that is ultimately what DirectX is for. Like any standard graphics API, it is up to the chipset manufacturers to figure out a way to make it run fast on their hardware by mapping its functions to their silicon, and then declare feature support to the API. Microsoft doesn't know the best way to make ray tracing run fast on AMD chips, because they don't have the circuit layouts or the driver source code. That's true for any rendering technology you care to name, from mip-mapping to tessellation.

And if AMD isn't releasing a driver, it is likely they also can't get it to run fast enough to be useful. From their perspective, they won't want to work on or advertise a feature that makes them look bad. "We support ray tracing, but it makes your games completely unplayable" is not a press release anyone wants to write.

[Antidamage]

"We support ray tracing, but it makes your games completely unplayable" is not a press release anyone wants to write.

Get ready for the "raytracing is a gimmick" wave on social media. Oh wait, that already started. Why even blow the dog whistle when they can blow it themselves?

[Tim Hobson]

Morningcoffee007 I think Antidamage mentioned Experimental as the keyword to describe a feature once it is released. The real time RayTracing feature will debut first as Experimental before even going to Early Access, like it happened with Niagara, and that will take a bit for the feature to leave Experimental and going into Early Access to finally going into Released.

Ray Tracing and Path Tracing features will ship as "Early Access" for 4.22.

Early Access for UE4 is defined as such:

Features available in Early Access give you the opportunity to learn how they work, plan your pipeline, and create test content. You should use caution when shipping with features in this state as they may not be optimized for performance or stability and may not be available on all platforms. We support backward compatibility for assets, and the APIs for these features are stable.

Experimental for UE4 is defined as such:

Features are sometimes made available in an Experimental state so you can try them out, provide feedback, and see what we are planning. We do not recommend shipping projects with Experimental features. Please keep in mind that we do not guarantee backward compatibility for assets created at the experimental stage, the APIs for these features are subject to change, and we may remove entire Experimental features or specific functionality at our discretion.

The RT Devs are tirelessly working to have some really cool things out the door at the launch of 4.22 for everyone. Improvements are being made rapidly in our 4.22 branch and not directly in our Dev-Rendering stream. Once the cutoff for 4.22 is made and features are stabilized, those changes will be merged back down to our Main branch and then down to the Dev-Rendering branch soon enough.

RT won't have every feature at launch, like Landscape support, which has been mentioned a number of times here, but it'll have a lot for everyone to check out. I'm not sure how long it will stay Early Access, but over the next release or two, there will be additional features coming online for sure!

[Thomas.Mayer]

Thanks Tim. You guys are doing an excellent job. Preview 2 is much better. Is raytraced transluency an active area of development? Preview 2 has some basic support(with issues). Would love to have that in early access with GI support, so that we can get some sweet caustics and interior reflections/refractions.

Tommy.

[TommyBear]

Thanks Tim! 4.22 is shaping up to be pretty excellent RT wise. Looks like preview 2 had some early support for ray-traced translucency. Can you share any info on whether GI will be supported with translucency any time soon? Would love to see some sweet RT'ed caustics. Also, is emissive surface support planned for 4.22? Thanks!

[NilsonLima]

Tim Hobson going Early Access this soon, this is what I call great news! I was aware of the definitions, but I was not really expecting RT coming into EA before more digesting with the community, great job all involved!! Now, the hype is something you guys need to take care, because with that said, the anxiety will be among us!