Any good HDRP AA options other than the four built-in, like on the Asset Store?

Unity Engine
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1

I was using TAA,and fairly happy with it most of the time (I like the softening of the entire image it was giving, but not the occasional ghosting), but then we added bushes and trees to our scene, and they get super blurry with TAA, with each leaf ghosting. Neither of the other two Deferred AA options seem to work very well, and we can’t use Forward rendering, so no MSAA.

So does anybody know of any other good AA options we can use? We have CTAA from the asset store, and a recent update says they improved how it works with vegetation (plus it has tons of settings, which HDRP TAA has zero settings), but CTAA doesn’t support HDRP yet.

2

SMAA is your best built-in option for that if you can’t deal with the TAA ghosting (I know it’s bad). I wouldn’t really expect wonders from CTAA either as it’s still temporal. There are no 3rd party AA modifications for HDRP atm afaik. I’ve modified the HDRP’s TAA a bit in past, to filter parts out and let them run in FXAA where I know TAA will definitely ghost but that’s not really a solution that could be used with foliage.

3

A possible solution is to approach this problem from another end and fix the underlying reason for vegetation experiencing heavy ghosting - which is usually vertex animation (wind flutter etc.) not correctly affecting motion vector buffer the TAA reprojection depends on.

4

Afaik HDRP does generate motion vectors for vertex animations that are time based nowadays, you may need some bleeding edge version for it tho. But TAA is still going to ghost no matter how much motion vectors you feed at it :confused:

5

Thanks, but we aren’t using vertex animations, this ghosting is just from moving past the unmoving trees using the Lit shader. I did enable motion vectors from transparent objects in both the HDRP asset and on the leaf shader, so it would affect the alpha-clipped leaves.


(this was captured at 60fps)

But yeah, ghosting is likely to always be a problem with TAA, even if it can be made a smaller problem. Which is why I was hoping there was another AA option that would work as well at softening the image and hiding aliasing, without making bushes and trees super blurry when moving past them.