TAA Ghosting on WPO

Development Rendering
1

So,I’m using TAA and when i walk and rotate the camera around my character,it ghost with the foliage behind(that have WPO),if i disable “Vertex Deformation output velocity” then it doesn’t happen,but then i think motion blur don’t work with it(right?)
Things that i tried:
Disable motion blur
Setting foliage to “Movable”
Setting “BasePassOutput=1”
i tried with ue5.5 and it still happens

So,what do i do?

2

Normal.
Nothing. Thats’s TAA.
You can makenit a little better by outputting WPO velocities in the base pass and setting up to spend rendering MS on fixing the ghosting a bit, but it’s not a cure all or much better in practice…

People generally disable motion blur if they can. The engine does some pretty bad motion bluring. Doesnt mean you should disable it, just dont rely on it for a clean render…

3

That’s normal, it’s called disocclusion and it’s likely Lumen doing it. If Lumen has no knowledge of the scene behind the character, then it will take time for it to adjust after disocclusion; since Lumen temporally accumulates over time.

4

Look,if i output velocities in base pass it still ghost,and motion blur on 0 also the same,every object that has WPO it ghost.the only way i found was to disable WPO,which dont look good.Does Previous Frame Switch help not ghost?even if i put “Current frame weight” on 1,which has 0 TAA ghost,it still happens…

5

WOW.i just multiplied the WPO by 0,and it still happens… i dont know what to do

6

Some versions of the engine have that pipeline completely broken - you could be on one of those - if so, you need to build the latest version of that engine which you can get from GIT to sidetrack the bug.

The only other thing you can do is to not use temporal AA…

7


here with 5.5

and here with 5.6
i dont think its a version problem.probably something im doing wrong.
to make this issue happens:i create a new project,put a material with WPO on a object and activate TAA,then it happens…

8

It’s how it works.
Look up what TAA is and how its supposed to function.

The ouptut velocities options is supposed to be able to eliminate some of the blur that the rendering method generates when a material affects WPO.

But if you think it looks like s*it, you are right. Epic’s engine - and their decision to use TAA - is made with the knowledge that it looks this way.

If you dont like it (as many) either change engine, or change your rendering to something else (MSAA? Forward rendering?)

1 Like
9

I will try to animate my grass in another way.
Thank you