You don’t. The reflections are actually very high quality, and provide much more overall detail than SSR. That being said, they bring detail to the scene, but are not high resolution themselves. They work poorly with materials that are smoother than 0.2 roughness, and are generally poor on a perfectly flat metal surface, such as a metal floor without normal mapping.
In case you didn’t notice, slide comes from NVIDIA VXGI slideshow and they are discussing those issues and how to solve them. is what they proposed:
Well it may be no problem for static objects but when objects move, is anotehr story, especially when the moving objects are dynamic GI sources using two bounces when they move. It is a common problem for many dynamic GI proposed solutions even the one I stumbled on for Cryengine using two bounces when objects move and cast reflections ( it is even more complicated since the moving objects are dynamic GI sources using two bounces when they move). I highlighted that way back in my comment:
https://forums.unrealengine/showthread.php?44278-Realtime-Dynamic-GI-Reflections-AO-Emissive-plugin-AHR&p=173638&viewfull=1#post173638
and I hope VXGI will find great solution so we won’t encounter such ugly pixel on reflections of moving objects
Also about about single bounce specular: VXGI did encounter some problems with some indirect specular coming from indirectly lit areas having objects not rendered in screen-space since it uses only one bounce, I really hope now that they will solve with their multi-bounce solution.
I noticed that it was official, but in gameplay the voxels are hard to notice. People who develop digital content will pick out every little detail, but when you sit down and play a game/watch an animation, small amounts of light leaking or voxels in reflections are minor enough that they aren’t seen unless you’re looking for them. And yes, moving objects do pose more issues, but I haven’t encountered any visual artifacts that are really major issues. The exception to that is specular tracing with only one bounce, but that’s something that is a problem in itself.
So I compiled a build of VXGI for 4.7.6 and while it seems to have identical results as the 4.7.4 build in the test scenes included, I’ve been having some difficulty getting it to display properly in my own scene. Specifically, I’ve been running into a lot of light bleeding, and the reflections don’t seem to work. I know it’s probably a setting I haven’t set properly, so figured I would just ask if there were any obvious solutions.
Is there any news of hairworks for ue4? I’m very interested in giving it a test, I often feel like fur is under developed in 3D and it would be pretty great to finally have something
to work with : D
Hi,guys please do something with shader compiling it is too slow. I realy like VXGI and I’m planning to make my project with VXGI.Please do something with it. 
And btw 2nd bounce looks great
What happen to Turf ? It seem to disappear from the radar. Can Turf Effect simulate flowers or is it currently limited to grass?
Hello friends,
Very sorry for the long delay and my absence from the forum lately, things have been busy with travel, etc. I’m happy to announce that the first-pass integration of HairWorks is up on Github now, /tree/HairWorks. There are plenty of issues yet to be resolved, we’re not happy with the shadows and aliasing, and there are other rendering artifacts and there. Also, first pass is implemented using Blueprints for managing and tuning the hair assets, and we expect will change in the near future, so please don’t expect any assets you create with first-pass integration to be future-proof. Be sure to plug in an Xbox controller when running the HairWorks map, the controls are blueprinted to the controller buttons right now; we’ll create a keyboard map in a future pass.
Thanks,
One reason why Turf dropped off the radar is that we need to resolve issues with transparency that limit it from being able to do anything other than grass.
We’ve had people looking at problem for several weeks now, but it is a tough nut to crack. It seems that we can’t do much to reduce the actual shader compile times, so we are looking to minimize the number of recompiles forced on you when you make a change.
Thanks for reply. 
Welcome back . and really thank you for the HairWorks repository. After seeing your work in The Witcher 3 for the HairWorks, I really expect to have same quality for UE4 if not better. Thank you very much.
Hooray!! Christmas is !
You’re welcome! I’m afraid we have several rendering issues to sort through before you will see UE4 match that level of visual quality. But we’re on it, so it’s mostly a matter of time.
I have noticed that parameters inside materials (not only material instances) can be changed without recompiling the material, I don’t even remember if it’s that way with normal UE4 as I haven’t used it for a while.
Really it’s not much trouble to create a material without VXGI switched on, when it’s roughly how you want create a material instance and switch on VXGI and boom, hardly any waiting.
@.
I’ve had some light leaking/issues when using Ray Traced Distance Field Shadows alongside VXGI (with Directional and Spot lights).
I’m still playing with it to see what’s really going on/if it’s my fault.
EDIT: I have to use VERY bright spot lights to really see behavior.
Hi , fantastic news, I have looked forward to hairworks for awhile and I will downlod and compile ASAP. Is there any news on the watershader for flex?
Thanks for these wonderful technologies.
The FleX water shader is running on my desktop PC and staged on our internal Git server, but there are several issues that need to be cleaned up before the devs responsible will sign off on releasing it. I’m optimistic that you’ll see it on Github later week.
No problem. Btw, does HairWorks support fluid shaders and alpha maps which make the hair wet and which implies the need of newer physics to make it look and move heavily (some are speculating that the Witcher 3 has that)? If so, then will you provide it for UE4? Thanks.
I’m not familiar with any hair-water tech, sounds like just rumors to me. I’ll look into it. Believe me, just getting the hair system together is enough work.
I don’t see why it would need fluid shaders for a wet hair look. Just needs to adjust the specularity of the hair, and as for physics you can probably tweak it until it seems to react more like wet hair.