Thread by @erkaman2

I will now write down a TL;DR of the paper below

"Adaptive Temporal Antialiasing".
casual-effects.com/research/Marrs…

Temporal Anti Alasing(TAA) is a frequently used Anti-aliasing technique,
but it struggles when the colors of pixels change suddenly,
and when objects get occluded and then disoccluded.

This is because it uses the color of the pixel in the previous
frame in order to compute a anti-aliased result of that pixel in the current frame.
But if the previous color suddenly changes a lot, we get artifacts.

Removing these artifacts requires complex heurestics, and much work.
This paper presents an alternative to complex heuristics.
It works like this:

especially at the edges of the screen, often objects will appear that were outside
of the screen before. obviously, we have no previous color info
for these new objects, so TAA is no good in these cases.

For these situations, we simply fall back to FXAA instead of TAA

Furthermore, we also detect pixels where TAA is very likely to struggle.
We identify pixels where the color luminance, and the surrounding depth values, and so on,
quickly changes, in order to find these pixels.

For these pixels, we cast rays using DXR according to a MSAA sampling pattern(8x, 4x or 2x),
When a ray hits some object, we get the color by just evalating the HLSL shader
at the hit point.

Of course, the big caveat here is that mipmapping is NOT available in DXR.
We get around this by always sampling the highest resolution texture in the mipmap chain.
Since we are already super sampling the pixel with an MSAA pattern, there wont be any
aliasing, even if we do this

also, ping the authors:
@acmarrs @josefspjut @rpsathe @CasualEffects