NVIDIA GameWorks Integration

[DAVE047]

So apparently the team that worked on Far cry 4 used "NVIDIA GODWORKS". Ha ha I have never heard of this one before but it was used to create godrays. It uses light from the sun or from another very bright light source. Environments could look even more majestic. This also would be an amazing integration mike!

Dave

[gboxentertainment]

The problem with less than 16 cones is that we start loosing definition on soft shadows. Then it will bring similar results to what we get with LPV (but without light leaking). Maybe the combination of VXGI with 5 cones and HBAO+ can bring nice results, but I couldn't get the merged branches two work (editor crashes at start).

Yes, this is where you have to accept VXGI as not the silver bullet for graphics at this point in time (maybe in the future it will be). The same thing is with reflections - which is why I have both SSR and VXGI specular turned on at the same time.

The key purpose I see for VXGI is diffuse gi - which is more efficient than any other gi technique that exists (i.e. highest quality for performance), with exception of the light leaking of course. I say this technique is more efficient because the more diffuse you make it (the wider you set the cone angles), the faster it is, whereas almost any other technique is the complete opposite because they have to be blurred manually.

[gboxentertainment]

Strange, it worked for 3 issues that were filed already.

I was the one that posted these 3 issues a while ago. Now I can't seem to post any new issues either - getting that unicorn.

[rabellogp]

Yes, this is where you have to accept VXGI as not the silver bullet for graphics at this point in time (maybe in the future it will be). The same thing is with reflections - which is why I have both SSR and VXGI specular turned on at the same time.

The key purpose I see for VXGI is diffuse gi - which is more efficient than any other gi technique that exists (i.e. highest quality for performance), with exception of the light leaking of course. I say this technique is more efficient because the more diffuse you make it (the wider you set the cone angles), the faster it is, whereas almost any other technique is the complete opposite because they have to be blurred manually.

How do you activate both techniques at the same time? Here when I turn VXGI specular on, it seems to automatically deactivate SSR.

[gboxentertainment]

Another issue I've found which I can't post in the github repository is with the view dependency. This seems to occur with spotlights and emissive lighting, when I look in a certain direction, the gi turns off. I believe that the view dependency of the voxelization (i.e. only voxelizing what the viewer can see) is what's causing this problem. Can you provide a way to turn off viewer-dependency? I understand that this is for optimizing performance, but for interior scenes with small amounts of lighting it is causing this problem.

[rabellogp]

Another issue I've found which I can't post in the github repository is with the view dependency. This seems to occur with spotlights and emissive lighting, when I look in a certain direction, the gi turns off. I believe that the view dependency of the voxelization (i.e. only voxelizing what the viewer can see) is what's causing this problem. Can you provide a way to turn off viewer-dependency? I understand that this is for optimizing performance, but for interior scenes with small amounts of lighting it is causing this problem.

I've also noticed that. But in some cases I've found out that it's the light itself that is being turned off while I'm not looking at it and the camera is not inside the Spotlig volume.

edit: No, it's not the lights... I did some more tests and turned out the shadows stuff is actually resolution changes that UE4 applies on them when I get far from the spotlight. And the direct light turning off case here was just the voxels near them not being generated while I'm not looking at them. You are right.

[gboxentertainment]

to VXGI developers: I just realised another way to optimize performance - you can create a way for users to select a low-poly version of each mesh that would only be used for the voxelization pass.

P.S. I still cannot post new issues in github

[Mikand79]

I noticed too once something gets culled from rendering it impacts GI, and if you stand in Directional Light shadow it seems to switch off GI. Though this all seems a bit random.

And there is no AO from VXGI that I would notice, but using the viewport controls in the upper left I was able to confirm UE's AO and HBAO+ do add up to each other (can switch them on and off there).

Further if I enable VXGI's specular nothing happens and SSR's aren't disabled.

[rabellogp]

I noticed too once something gets culled from rendering it impacts GI, and if you stand in Directional Light shadow it seems to switch off GI. Though this all seems a bit random.

And there is no AO from VXGI that I would notice, but using the viewport controls in the upper left I was able to confirm UE's AO and HBAO+ do add up to each other (can switch them on and off there).

Further if I enable VXGI's specular nothing happens and SSR's aren't disabled.

This is strange... Here SSR and VXGI specular just won't add up no matter what... I can clearly see the SSR disappearing when I turn VXGI specular on... I say that because if the scene has no first bonces on sight, the little SSR reflections just vanish when I turn VXGI specular on and there is no reflection at all... I'd like to see how it looks like to combine both of the techniques though...

About the culling system, yeah... That is what gboxentertainment was pointing out. It should be a way to increase the distance from where the voxels start disappearing when not on sight... But maybe there is no easy way to do that. I mean, if UE4 is not rendering the geometry because of its culling system, the voxelization should be aware of geometry disposal without dependence of UE4 rendering system.. I don't know, I'm just guessing here...

[WinterLanternPro]

Hey Mike,

Hope you had a great GDC. Any word on Flex surface rendering?

Thanks

[fdslk]

So, here's what I've been doing lately with VXGI. I must say I'm pretty impressed with how much I got with so little tweaking, yet, my input for VXGI is that it still needs to get better documentation and fix some minor issues with the VXGI specularity.

[zHD131z]

Flex does not work on the graphics card GTX 460?

[gboxentertainment]

Further if I enable VXGI's specular nothing happens and SSR's aren't disabled.

If you look through an earlier part of this thread, I provide a way to enable this.

[OlekKing]

PhysX and Apex are both fully implemented and integrated into Unreal Engine 4, correct? Can they be considered core features of the engine?
Their implementation is CPU based, meaning that a system with an AMD GPU could run them and use them, correct?

I would like a clarification directly from Epic Staff, thank you very much.

[GalaxyMan2015]

PhysX and Apex are both fully implemented and integrated into Unreal Engine 4, correct? Can they be considered core features of the engine?
Their implementation is CPU based, meaning that a system with an AMD GPU could run them and use them, correct?

I would like a clarification directly from Epic Staff, thank you very much.

Im not from Epic, but here is a quote direct from them

Hi Sabino,

PhysX 3.3.1 is already integrated into the engine. There are typically plans to upgrade the PhysX to the latest versions when they are released. However, this requires testing and making sure things integrate properly though.

Keep any eye on the release notes for each engine version as the update would be listed there.

Thank you!

Tim

PhysX Destruction are is handled on the CPU and is card agnostic. The performance will depend on the users system. The best solution with targeting multiple systems is to build and test often.

The goal with anything in the engine is that it will run with both AMD and NV cards. Epic does not want to split the community and appear biased towards a single GPU. Just as a recap because it has been mentioned a number of times, and even in some previous posts you have made about destruction meshes, there is no benefit with the out-of-the-box integration's with those who have a NV card over an AMD Card.

Now the above is about PhysX Destruction, but is the same for Apex, especially the end part of the quote. They are not biased towards a single GPU.