MasterDisaster
Regular
I've heard, some time ago, an interview where epics admits that UE3 scales bad with MSAA turned on, because of his internal nature, There's any dev that can clear this concept?
UnrealEngine3 limits (MSAA)
- Thread starter MasterDisaster
- Start date
ShootMyMonkey
Veteran
Was the comment about MSAA in general or MSAA specifically on the Xbox360? The latter is a tiling problem, and UE3 was never built with that in mind. It is, after all, basically a PC engine that has some codepaths for consoles tacked on.
If it's the former... I don't know for sure just from your post.
If it's the former... I don't know for sure just from your post.
scooby_dooby
Legend
pretty sure it's in general, something to do with the way they do shadows.
I don't believe Epic ever said that tiling was the issue at all.
http://www.nvnews.net/vbulletin/showthread.php?t=70056
Seems to me like he was talking about all platforms, not just the 360. He certainly didn't blame tiling at all.
MasterDisaster
Regular
no, they are talking in general of the engine..
this is not a good thing, a lot of games will use UE3, I just want to know what's the problem of the engine and some effects when MSAA is active
It's been covered before, do a search, basically they reverse project screen space pixels into shadow space. So the cost of the shadows is proportional to the number of pixels prior to the downsample. So 2xMSAA doubles the cost of shadow rendering.
It strikes me there are several ways they could try and address this, but I have to assume that they tried them.
But UE3 doesn;t specifically limit you to any particular shadow approach, the app could easilly provide a different solution.
It strikes me there are several ways they could try and address this, but I have to assume that they tried them.
But UE3 doesn;t specifically limit you to any particular shadow approach, the app could easilly provide a different solution.
MasterDisaster
Regular
ShootMyMonkey
Veteran
Ah... well if that was what he was talking about, that makes sense. I don't know for sure the specifics of Epic's own implementations, but getting back the light-space information for every sample like ERP mentioned is costly, and also you have some potential issues with certain types of data buffers anyway as regular old MSAA was meant for color and not everything behaves the same.
I think approaches like using a scaled light distance value would work just fine in many cases so long as the shadow is necessarily soft, but since they make a point of honor out of progressively softening shadows, that gets iffy.
Considering how common UE3 looks to be on 360, I really think Epic should have gone out of its way to get MSAA to work fully on the hardware. It's an extremely important feature for image quality, and so much of the 360's GPU is built around MSAA support. To just throw that away... HMMM.
Alright, so occlusion techniques don't work well with MSAA according to Epic. Worst-case scenario, if another technique can't be found: just brute-force it then! Xenos has tons of fillrate. Some guy at Rare stated that Kameo's engine drew multiple copies of hundreds, if not thousands of on-screen guys by mistake with no drop in framerate. Let the hardware take it on the chin if neccessary so that we can have our MSAA.
Alright, so occlusion techniques don't work well with MSAA according to Epic. Worst-case scenario, if another technique can't be found: just brute-force it then! Xenos has tons of fillrate. Some guy at Rare stated that Kameo's engine drew multiple copies of hundreds, if not thousands of on-screen guys by mistake with no drop in framerate. Let the hardware take it on the chin if neccessary so that we can have our MSAA.
Something to note, Bioshock is using UE3 and the screenshots released of it so far have AA. So either Irrational have been releasing highly supersampled bullshots or it's not an insummountable problem and it's possible to get MSAA to work... but we don't know what they've done to the engine
BioShock uses a heavily modified UE2.5.
/me does some more research...
Oh, it's seems it UE2.5 with some UE3 additions. Rendering engine is probably still UE2.5 based then.
Oh, it's seems it UE2.5 with some UE3 additions. Rendering engine is probably still UE2.5 based then.
Yeah, that is how understood it as well, a heavily modified UE2.5 but the toolset of UE3
...MasterDisaster
Regular
Yeah, that is how understood it as well, a heavily modified UE2.5 but the toolset of UE3
right, they are using vengeange engine (UE2.5 based) with portions of UE3 (as Splinter Cell: Double Agent and Duke Nukem Forever)
edit:
http://en.wikipedia.org/wiki/Vengeance_engine#Enhanced_version_of_Vengeance_engine
Last edited by a moderator:
so what do u mean? that the shadows are tacked on afterwards?
ie its not using, shadows == absense of light
Similar threads
- Locked
