NVIDIA GameWorks Integration

You can clone the git repository, switch to the right branch, and do a “pull” every time you need to update. That’s quick and only refreshes the modified files. Then you need to build it.
I’m sure you can find some instructions online on how to do all that.

@Alexey.Panteleev - Nicely done! You cats are killin’ it :smiley:

Thanks for those fast updates @Alexey.Panteleev VXGI-2.0 is an incredible upgrade over the previous version.

Someone asked me some help for it: here is a video about Installing Luoshuang’s GPULightmass (need Nvidia Maxwell+ GPU) on top of the 4.19 Gameworks build:

Thank you for your effort. I have just noticed that fps drops again when VXGI enabled in Post Process but not in Directional Light so there is no visual change again because the only way to use VXGI is enabling in both of them (directional light and post process volume). I wanted to share, it might help.

@0lento Thank you for the branch:…9-GameWorks-VL work very well:D

Impressive list of updates indeed, thank you. Especially happy to see TXAA support on forward.

I think HBAO+ used to crash or just not work on forward either but it’s bit harder to solve if you want to keep using HBAO+ on top of everything (it was like that on old integration at least) as it will not give correct results in forward for obvious reasons. We fixed this in past by doing it like this instead on 4.15:…996372c2464436, this change also makes AO to only happen in shadowed parts which may or may not be the preferred way (this is how unreals SSAO does it as well - but it doesn’t work in forward either).

That’s not really a bug. When you enable VXGI in general, the engine will do all the relevant passes, like voxelization and cone tracing, and that’s what creates the perf drop. It just so happens that you don’t have any lights or emissive objects enabled to actually contribute indirect illumination. It’s possible to track this case by looking through all the lights and all the meshes ahead of time, but I think it’s a corner case, and it’s not worth doing that analysis all the time, as usually it won’t make a difference.

Also, now that 4.19.2 has been officially released, I’ve updated the VXGI and TXAA branches to be based on this engine version.

I’m having issues with the branches with VXGI 2.0. Whenever I turn on VXGI Diffuse everything in the scene turns red. I’m uploading two screenshots with VXGI on and off for comparison. Also, when i turn on VXGI Specular I get the following error:

[File:C:\UnrealEngine-4.19\Engine\Source\Runtime\Windows\D3D11RH\Private\D3D11NvRHI.cpp] [Line: 257]
VXGI Error: computeSpecularChannel is unsupported in Ambient Occlusion mode [GI_ViewTracer_Specular.cpp, 48]

I already installed this branch in another PC with no problems, so I have no clue about what went wrong here. The PC I’m trying to run this branch on has a 780GTX Ti and Windows 10, while the other PC, with the working engine, has a 970GTX and Windows 7. Those are the only differences.

Any clue about how i could fix this? Thanks in advance!

It won’t work on a 780 because it’s Kepler. You need at least 750 Ti (Maxwell-1) or 9xx to run VXGI in non-AO mode. Also, are you running the latest version that I pushed yesterday, or something older?

@0lento - your branch seams to work fine. I had some issues but they turn out to be my bugs.
So for tried on three projects - no crashes so far.

I updated all three 4.19 GameWorks merges I’ve done to include latest fixes from Nvidia (for TXAA3 and VXGI2) and official UE 4.19.2:…4.19-Flow-VXGI (Flow + VXGI 2)…4.19-GameWorks (Blast + Flow + HairWorks 1.4 + HBAO+ 4 + TXAA 3 + VXGI 2)…9-GameWorks-VL (Blast + Flow + HairWorks 1.4 + HBAO+ 4 + TXAA 3 + Volumetric Lighting + VXGI 2)

That’s nice to hear, but do test the packaging too. Like mentioned I couldn’t use shipping conf on Volumetric Lighting for some reason on my initial merge. There could be some issues with other techs on shipping builds too as I haven’t tested that conf extensively.

Development conf on each GameWorks tech seemed to package just fine (I’ve test packaged and ran the packaged version for at least one sample from each GameWorks tech to make sure everything seems to be in order on packaged builds as well).

Please, can somebody test trueSKY with VXGI 2?

I’m using Truesky with VXGI 2.0 since VXGI 2.0 came out and have no issue ^^

Then I keep trying. VS2015 may be having problems. Thanks for the info.

thanks for the quick reply. I just tried your latest build and the issues are gone, no more red light and no more crashes. Is there anyway I can use VXGI in this build with my 780, since r.VXGI.AmbientOcclusionMode= 0 means no VXGI and my GPU doesn’t support r.VXGI.AmbientOcclusionMode= 1?

r.VXGI.AmbientOcclusionMode= 1 means you can only use VXAmbientOcclusion.
r.VXGI.AmbientOcclusionMode= 0 means you can use Full VXGI+AmbientOcclusion.

@Alexey.Panteleev I have just tested the updated branch. I noticed VXGI voxelization and tracing frame times are good but when I enabled VXGI (Only Directional Light) with optimized parameters, my fps drops 97 to 48 on GTX 980Ti because of shadow depths. Is It usual or there is another problem? I uploaded GPU profiler results. First: Shadows and VXGI enabled (GI only). Second: Shadows enabled but not XVGI. Third: Shadows and VXGI disabled. Fourth: Shadows disabled VXGI enabled (GI only). Also, I noticed that in fourth scenario GPU visualizer shows 3 ms less than viewport values. Is this “half of the fps” situation nature of VXGI? I thought that VXGI 2.0 would be much faster than old one, up to 2x according to updates. But fps which I had drop doesn’t verify this is true.

@0lento - I’ve managed to package project using your branch.

In this case, a large part of the fps drop comes from shadow map rendering, the ShadowDepths pass. Like I mentioned, when VXGI is enabled, the directional light shadows include all objects that are covered by the shadow map, not just those affecting the current camera view. You can see that using “vis ShadowDepthAtlas” or “vis WholeSceneShadowmap” and toggling VXGI on and off. It’s probably possible to do some culling still, or limit the range of cascades that are used for VXGI. Since you observe such a significant slowdown, it would be great if you could send me the scene, or something else that reproduces the same kind of slowdown, and then I can try to optimize the code (or settings).

VXGI 2.0 is generally faster than 1.0, but no one said you will see 2x speedup overall. In the GDC presentation, I mentioned that voxelization can be almost twice as fast in some cases, mostly because it can be done in a single pass now. Other things like voxel processing and tracing have been somewhat improved. But not shadow map rendering, as that’s part of the engine, not VXGI. (Actually, it’s probably possible to implement single-pass directional shadow map rendering using Maxwell-2 FastGS, which should give a speedup for everyone using UE).