Vulkan status

RCaloca · July 30, 2016, 1:06am

Thanks! Can’t wait to get it all done

John_Alcatraz · August 3, 2016, 8:28pm

Now that the 4.13 Preview is out which is quite close to master I guess I tested the particle effects demo again.

It’s always a bit annoying to have to wait for 10,000 shaders to compile, that takes roughly 20-30 minutes on my i7 5820k @4.2Ghz.

Unfortunately it didn’t finish compiling the shaders and instead after a while it crashed. I created an answerhub post about it with callstack and log: Vulkan crash - Rendering - Unreal Engine Forums

RCaloca · August 3, 2016, 8:37pm

Interesting, and master is failing as well? 4.13 and master a little off.
I’ll try to give it a go here.

John_Alcatraz · August 3, 2016, 9:01pm

I have not tried master since I would always be behind with that and compiling takes so long that I don’t really want to spend the time every few days compiling that again…

I restarted it and this time it worked, no crash Though it also started directly with compiling the remaining 4500 shaders, so if the crash would have been triggered by compiling a certain shader then yeah. But I think it was more of a random crahs that isn’t really reproducible. Or maybe related to that the game already run for 10-15 minutes while it was compiling shaders and then maybe something leaked somewhere until it crashed, I don’t know.

The game looks a lot better now than with 4.12. The flickering with the artifacts I got was fixed by a newer driver, so that was already fixed in 4.12. But the bug that particles are sometimes only rendered on half of the screen with a cut through the center is fixed in 4.13. It’s running quite smooth.

Remaining bugs I see:

The resolution is still “low”. Same like in the video I took with 4.12. It’s just not rendered in the native resolution of the window. Looks like a screen percentage of 50%. Also, r.screenpercentage does not work, no matter what number I use nothing changes.

http://puu.sh/qoOzD/ecf34d0553.png

Alt+Enter to go into fullscreen doesn’t work. The game window moves to the top left of the screen and the elements windows draws around the window disappear, but the rendered area does not get bigger and the lower and right part of the screen just stay transparent (I see windows behind).
If I go into fullscreen with r.setres 1920x1080f then it’s the same, just that the lower and right part of the screen don’t show windows but they are black now.

So the resolution just doesn’t change.

I’m quite sure in this area should be snow, right? I see no snow there. Or is the snow in general something that just disappears with mobile and only works on desktop?

http://puu.sh/qoOUg/e9a28d338e.png

The railing looks very aliased, as if all AA would be turned off on it.

http://puu.sh/qoOZ5/86bb59f7d0.png

There is still this something that just fills the whole screen with a white plane when looking from that exact position (also seen in my old video):

http://puu.sh/qoP7c/06cf0de6c7.png

Highreshot crashes. I guess that just wasn’t implemented in vulkan yet so its expected to crash?

So some small bugs, but overall it looks and runs nice

RCaloca · August 3, 2016, 9:16pm

Cool, you can also omit the -vulkan parameter and that will run the PC mobile version under D3D11. I’ll make a ticket to investigate these issues! For sure, resolution change is not implemented yet.

motorsep · August 3, 2016, 9:19pm

Vulkan can run on Linux too (Steam Machines including)

Btw, any chance for Vulkan to work on Gear VR any time soon ?

John_Alcatraz · August 3, 2016, 9:31pm

Ok, I have just tested with regular mobile and there the bridge scene looks like this:

http://puu.sh/qoS4d/e1841878da.png

http://puu.sh/qoS7b/242dd57bc4.png

So Vulkan misses the fog and snow particles. Also that flat white thing I get with vulkan doesn’t appear without vulkan.

The aliasing of the railing still exists with regular mobile rendering though, so it’s not the fault of Vulkan.

And is the shader compile with Vulkan a lot slower than the shader compile without vulkan or did it just feel like that?

RCaloca · August 3, 2016, 9:50pm

Sounds like the SDK has to be made to work with Vulkan, it’s OpenGL right now.

John_Alcatraz · August 3, 2016, 9:59pm

I just saw the lightshafts are missing in Vulkan too:

http://puu.sh/qoSFk/71223ddbc0.png

http://puu.sh/qoSOH/9afaf2823d.png

But I also saw the low resolution seems to be quite similar in regular mobile. Any idea what is keeping the resolution so low? Do you see the same when you run the particle effects in regular mobile ES3.1 or in Vulkan?

Just for comparison, this is how desktop DX11 looks like in same resolution:

http://puu.sh/qoTsO/7c5c63ed5c.png

RCaloca · August 3, 2016, 10:01pm

Not yet, might be one of the post effects has an issue. RenderDoc would probably tell what’s wrong. I’m trying to get these fixes in for 4.13

John_Alcatraz · August 3, 2016, 10:07pm

Ok, nice I added another screenshot in my last post showing how it looks like on desktop. You see its sharper on same resolution. It also has more nice rendering stuff of course, but thats not so relevant at the moment since thats expected to be missing on mobile.

motorsep · August 4, 2016, 1:22am

SDK as Oculus Mobile SDK ?

RCaloca · August 4, 2016, 1:07pm

I think so, that’s what I got from the VR team

RCaloca · August 4, 2016, 1:08pm

Ok, I (don’t?) see the snow on Vk. I’ll see if I can fix that for 4.13.

John_Alcatraz · August 4, 2016, 2:18pm

You do see it or you don’t see it?

And you said resolution change isn’t implemented yet, but the protostar demo was running on a high resolution so there has to be some way to set a higher resolution?

RCaloca · August 4, 2016, 2:26pm

I see that I don’t see it
You can pass the resolution as an argument, like -resx=1600 -resy=1200, but if the post is broken it might look blurry/pixelated. You can do show postprocessing in the console to test.

Tymax · August 4, 2016, 2:39pm

Cant wait until Vulkan is ready to use with the Unreal Engine!
For the biggest part I expect performance increases, unlike from the shady DX12 wrapper, so take all the time you need and even a little more
Nobody wants shitstorms in tech communities like ROTTR caused with their ontop DX12 “functionality”.

John_Alcatraz · August 4, 2016, 3:19pm

Ah, you see that you don’t see it, that makes sense

I have tested with -resx=1920 -resy=1080 and when toggling PP with show postprocessing it looks a lot better So you were right, the blurryness is the fault of the PP.

https://puu.sh/qpEVO/68c02c3b5c.png

I also tested with -resx=1920 -resy=1080 -fullscreen and that works great too!

Edit: Is there some way to disable Vsync with Vulkan? Having disabled framerate smoothing in project settings and also r.vsync 0 still don’t disables it. In DX11 desktop its disabled, but vulkan is limited to 60 fps.

motorsep · August 5, 2016, 4:32am

After talking to Oculus it seems that this iteration of Vulkan is not made for VR. Hopefully Khronos will get next iteration VR compatible (mobile VR specifically)

RCaloca · August 5, 2016, 5:47pm

Not right now, it will involve playing around with the way we handle swapchains & backbuffers, so I’ll add it to the list but will be down in priority…