Sigh. Apparently I need to weigh in on this TAA topic. MSAA is an antiquated technique designed to generate more samples on polygon edges as that was the only area that was undersampled at the time. 1/12

It's relevant lifetime lasted from colored triangles through textured triangles. It was artificially extended through per pixel shading and early days PBR with NDF prefiltering. It ran out with artist created material shaders. 2/12

From that point on the signal was undersampled when using only a single sample per pixel, independent of polygon visibility tests where MSAA applies. 3/12

In the modern age of Monte Carlo integration and ray tracing (that we have at least partly been in for a generation and firmly are in now) we need a vast number of samples per pixel. 1 will not do.

This means supersampling is required. 4/12

For real-time it isn't practical to generate those all in a single frame. In some RTing contexts sample sharing can be done spatially. That isn't possible for a large class of problems as evidenced by the fate of MLAA and it's decedents. 5/12

So we are left with temporal accumulation of samples.

Will this go away anytime soon? I argue no. It is going in the opposite direction.

The amount of cost to generate a pixel is increasing faster than hardware power and slower than screen resolutions. 6/12

The signals being sampled per pixel are increasing in their frequency and variance, all motivated by Monte Carlo integration of the rendering equation. 7/12

Temporal upsampling has gained great popularity as a means to generate less than 1 sample per pixel as the cost of those samples increases. More sophisticated denoisers (distant decedents of TAA) accumulate even more samples than old TAA ever did. 8/12

DLSS and new innovation in temporal sample reuse is the future and will continue to be our reality for a very long time, until we have enough power to generate numerous path traced samples per pixel in a single frame. 9/12

The question "Is TAA optional?" is really the question "Is image quality optional?". I've argued for years it shouldn't be optional in Fortnite but I don't ultimately make that decision. TAA and actually AA altogether can be disabled along with shadows. 10/12

The real question there is about player choice and how to create a level playing field for a competitive game that supports a wide range of hardware. That is a much more complicated question. 11/12

Now if folks want to debate what space is best to accumulate samples temporally, screen space vs others, that's more interesting and understandably contentious. 12/12

PS. Even if you accumulated shading samples in another space, micropoly geometry now means nearly every pixel is an "edge" pixel. Traditional hardware MSAA will still not be the solution.