I’ve been noticing extreme slow downs wherever I use MSAA even at the lowest settings up to 50% speed drops. I noticed same scenes in unity work much faster and much cleaner.
I’m not sure what the trouble is, maybe someone can shed light on this. But if others have experienced similar issues please write here as I hope Epic doesn’t abandon their work on forward shading and MSAA combo. I noticed no new updates have been done here since the VR buzz died down.
So many types of games really need this feature to be as efficient as possible. TAA is a real no go in many situations.
I am forcing quality settings from console on startup in the level blueprint and i’m testing with lowest MSAA settings of quality = 2 VS no AA at all and the jump is around 50 % difference, my scene is entirely unlit, (almost all green shading view debug) a few translucency layers, Geometry edges also show over 75% green and only around 10% red/white in some distance objects (something Epic had mentioned to watch out for with MSAA and forward shading).
My Video card is 1060 Nvidia. I must also note that i am using to test it for both VR and non VR. and the drop on both are significant. for VR it drops from 90-100+ FPS to 30 - 45 fps on final packaged files (without AA vs with MSAA quality 2) subsequent quality settings 4 - 8 make little difference after that. Also no super-sampling involved.
I also noticed the MSAA settings even on highest quality are making small difference to clean up some of my edges vs what i see in Unity where even the lowest settings displays very clean geometry edges.
I also ran the entire first section of the game in Unity with shadows and some lit materials inside the editor with double MSAA quality and it was giving us 75 - 80+ FPS inside the editor and on an
un-optimized scene comparatively - in VR mode. (pure graphical test no game logic at all these stages of testing).
I hate to bring up Unity vs UE comparisons but initially the project was started in Unity so it gave us something to compare it to.
For the record TAA in UE4 gives faster results than MSAA but the output is much too blurry to be usable.
MSAA is expensive. Epic has shipped a game (Robo Recall) using the MSAA that’s in the engine, and if Epic ships a game with some feature you can be quite sure that it has the best possible performance that is theoretically possible. Most likely, there is nothing that can be done to improve the performance of MSAA further. It’s not like that is “new” tech with a lot of optimizations that are possible to add in the future.
I just use TAA, which also works perfectly in VR, and especially now with the TAA upscaling, is just awesome.
I tried first at native oculus vr res (Pixel density 1) and then another one with 1080p for desktop.
I’m sorry I wish it was the case with me. Epic is a very large studio and it’s their engine which they know the ins and outs of. We are in the very indie dev side of things using a second party tech that we may not fully understand sometimes.
Also TAA still didn’t work for me in this case as my units on screen are small, have thin geometry in some places and there are small particle effects and geometric details entirely lost because of the blurring. They were all designed with sharper AA and soonest TAA comes along some of the effects entirely disappear, one such effect is particle ribbon, which entirely vanishes, I have to redo most particle effects and some models to make them all thicker to compensate. I can try up scaling again for the sake of trying and see if it works. Maybe TAAU can help…
One other reason I was concerned about MSAA is because I read in multiple forums including one on reddit that devs were complaining about the MSAA integration in UE and how its not working for them, that prompted me to write here to try to see if this is an occurring problem other than my case.
I need to be sure before I could move on,
Edit: just read more about TAAU Maybe it will help with those details, will be on my next to do list.
TAAU is for rendering at lower res and upscaling with good quality, so it won’t make TAA look better. But for particles etc, you need to use a translucent material with “Responsive AA” checked, then that will look fine with TAA and no longer “vanish”. Try that, without using that TAA is definitely ugly on particles, but when you use that responsive AA checkbox, it should be very fine.
Thanks for the tip will try it out. I tested TAAU and it made no difference in terms of sharpness as you said the doc was a little confusing, they mention it preserves details like fences and such, but left me a little puzzled as to how exactly its supposed to accomplish this when its down sampling and then running another pass over that.
I assumed it would be rendering at twice the screen size and then scale it down to actual screen res to preserve detail with some magic low cost somewhere.
But even assuming particles get fixed up there is always that issue of detail loss and an overall blur. Which brings me back wondering why MSAA is so slow in UE4?
I will not dwell on it as it may be hopeless and would have to find a way out of it. I hope there is a way to make MSAA faster and cleaner and that Epic would look into it somehow. If indeed it’s the case.