NVIDIA VXGI Dynamic Global Illumination inside Unreal Engine 4

Important! The results as displayed below are based upon a outdated version of both Unreal Engine 4 and VXGI.
There have been many interesting updates to VXGI since the publication of this post and I’ll do a review on the latest version shortly.

A while ago NVIDIA announced its new Dynamic GI called VXGI.
Now integrated in a separate branch of Unreal Engine 4, I couldn’t resist doing some tests for fun and stuff.

  • Watch the video on my Vimeo:
  • Or on NVIDIA’ Youtube (with different music so it’s a whole new experience! Well, kinda…):
  • Couple of renders taken directly from several testscenes with the ‘highres’ screenshot ability (1920×1080):


So what gives? Is this relatively new dynamic GI method worth giving a closer look? I reckon it is! Currently the most accurate solution available, nothing comes close if you’re talking about quality versus performance. Even though still a beta, it already impresses with really good colorbleed, AO and its single light bounce. Add to that NVIDIA is looking into integrating a second bounce whilst improving the output and you’ve got a really strong contender for dynamic GI in games and maybe even Arch-Viz.

Important! The results as displayed below are based upon a outdated version of both Unreal Engine 4 and VXGI.
There have been many interesting updates to VXGI since the publication of this post and I’ll do a review on the latest version shortly.


  • Not limited to ‘Maxwell’ GPU’s (!)
  • Accurate ColorBleed from Diffuse
  • Ambient Occlusion (as opposed to Screen Space Ambient Occlusion)
  • Stunning GI from Emissive materials
  • Specular tracing offers an interesting alternative to SSR
  • Looks fairly good on low-settings/low-performance impact
  • Can look incredible on high/extreme settings
  • Excellent tweak and management controls
  • Fairly good range before quality degrades


  • Requires recompile of Master Materials for Voxelization
  • Recompiling Master Materials takes longer than acceptable.
  • Poor stability when certain scenes include animated assets.
  • Prone to small lighting errors even on fully static scenes.
  • No GI from lit particles.
  • Does not support all Material types.
  • Specular tracing yields rather low resolution for reflections.
  • Small objects still need SSAO and SSR or will ‘float’.
  • Can be tricky to tweak for scene-specific circumstances.
  • Separate Unreal Branch, lagging behind core developments.
  • Slim chance of ever getting integrated into main branch.

Important! The results as displayed below are based upon a outdated version of both Unreal Engine 4 and VXGI.
There have been many interesting updates to VXGI since the publication of this post and I’ll do a review on the latest version shortly.


In short:
When it works it looks really good.
It does however come with a few strings attached so to call this production-ready
is simply too soon. I’ll be keeping my eyes on this one for sure!

With the above in mind, performance was a good surprise. I have a GTX Titan GPU (not a Titan X!) and my pc can be considered ‘average’ by today’s standards. Even though VXGI can be easily set to cripple your fps (32 cones, very low trace-step etc.), if you keep things on defaults or around that range, it still allows you to have the experience without your scene becoming a slideshow. This is of course a generic impression and since polycount and scene-complexity (number of lights contributing to VXGI, shadows etc.) do impact VXGI, I guess for now performance is as good as you want it depending on your hardware and your scene-specifics.

Note: Even though this demo wasn’t done in 2 hours (creating the scenes, rendering the clips and putting the lot together took me 2 days total). It’s kind off important to mention none of it was made with the intend to impress on scene-fidelity or complexity. Geometry was kept deliberately simple as were materials, as was lighting. I was most interested in the core functionality of this tech and didn’t want to go all out before even mastering the basics. As such you should judge the quality on a different basis as if this was a video made to reflect any kind of realism. Freely translated you could close this with ‘If it already looks like this on nothing but some quick experiments, imagine what it can look like if given some hardcore lovin’ 😉

I hope you enjoyed reading all of the above!



2) GPU Technology Conference NVIDIA VXGI presentation

2) NVIDIA Gameworks on Unreal Engine 4 Forum







  1. Giorgi Kikuashvili 08/11/2016 at 09:00 - Reply

    This looks AMAZING.
    Do you guys imagine a reboot of Will Rock with this kind of graphics + APEX destruction and turbulence?
    It would blow minds, especially in VR.

  2. waseem bata 10/09/2016 at 18:19 - Reply

    hello , such quality here , i have some requests , can you make a tutorial about placing the right lightning , and it would be better if you made a tutorial about the whole vgxi , i am using it but not satisfied with the results , and thanks

  3. lcolnaghi 03/08/2015 at 00:12 - Reply

    Hey! Downloaded commit 04a9f94 from VXGI-dev branch, and the latest hbao+ branch, merged the ssao+hbao .dlls in the vxgi-dev content/nvphysx folder, and everything is up and running fine! The emissive content is working at last!

  4. expomila 08/07/2015 at 16:54 - Reply

    Hi this plugin is very interesting , I wonder how to install version 4.8 of Unreal used as URL or any tutorial you have esta información Where is he?

  5. coogelblitz 15/04/2015 at 11:55 - Reply

    i have a question about vxgi…
    does your vxgi algorithm uses dx11.2 tiled resources(or opengl resident textures)?

  6. yeshay 12/04/2015 at 07:22 - Reply

    Hi http://www.livefyre.com/profile/5422514/ truly amazing work of yours as usual….  where can i get the title effect with fire used in your video…?

  7. YolanDiego 11/04/2015 at 19:00 - Reply

    Mantle is not open but opengl is.

  8. Byzantos3D 08/04/2015 at 10:22 - Reply

    tommycpu3 Thanks Tommy. (I hope you are wrong :-))

  9. Byzantos3D 08/04/2015 at 10:21 - Reply

    @stucki Thanks Stucki. Performance depends on a lot of settings of course but the impact from enabling VXGI is about 30-45% of your base-fps I’m guestimating. That’s of course a lot and way too much for games but with clever usage you can at least use it fine.

  10. Byzantos3D 08/04/2015 at 10:15 - Reply

    JerwelGo Hi Jerwel, This was done in Unreal Engine 4. For the Garden animation I made all the trees (yes Speedtrees) and those were incorporated in Lumion 4.5. Hope that helps!

  11. JerwelGo 08/04/2015 at 06:53 - Reply

    Hi Byzantos! 

    was this animation done in Lumion or Unreal Engine 4?
    – i’m confused because i’m not familiar what is Unreal engine 4 for? is this has something to do with Lumion to create this kind of photorealistic output?
    – also i have some questions to your THE GARDEN animation. how did you make the trees/plants so detailed and looks realistic? did you use other application to make it like that? SPEEDTREE?

    please correct me if i’m wrong.
    thank you for any response you can give (:

  12. stucki 07/04/2015 at 17:21 - Reply

    Hi, Aaron,
    congrats on achieving these amazing results !
    i really like them very much.
    lets hope it gets inside the “user” branch of unreal engine, soon.
    how much frames do you “loose” to gain the effects ? (percentage)
    kind regards

  13. tommycpu3 04/04/2015 at 21:08 - Reply

    Byzantos3D Gilson Antunes yeah do to nvidia’s closed mentality this will fail anyway.

    Gameworks is just to benefit nvidia and not the industry as a whole unlike the effects of AMD’s low api push.
    Amd changes the industry and nvidia creates new AA for gtx cards.

    I would even say nvidia does a disservice to their engineers who work hard to make this stuff just for it to be swept under the rug do to it not being industry wide..

    Anyway very good work by the artist!! It looks amazing!

    Would love to see a walk through to see what it would feel like to be in a game using this technology.

    great stuff!

  14. Byzantos3D 03/04/2015 at 13:19 - Reply

    Gilson Antunes Thanks Gilson! I’ve updated the post and the video with some new things too.

  15. Gilson Antunes 02/04/2015 at 21:28 - Reply

    Great trials, great images. Congratulations !!

    VXGI seems to be an excellent tool for the RT system.
    These comparison shots spectacular VXGI off / on.

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