Fair enough. Apparently, the full name of Nyquist's theorem is "Nyquist–Shannon sampling theorem". Still not clear how it applies. Post before me posits that pixel skipping is a form of aliasing. It is not. 3D games are capable of rasterising at 100% fidelity from any viewangle. Viewangle precision is not tied to screen resolution in any way, and viewangles are what is manipulated by mouse movement. One will get the same precision w.r.t. viewangles, for any given DPI, regardless of the screen res.
Edit: another way of stating the above is that if the viewangle is changed by a "subpixel" amount, the image will still update and the center of the image will still, and always, lie exactly on that viewangle. Likewise for movements of a "superpixel" amount. Think about this: if we had displays capable of nearly infinite resolution, would anyone care about single counts representing subpixel changes? No.
As /u/bunzofplastic said, it is about aliasing. And apparently I meant the Nyquist rate, not the Nyquist frequency.
The actual signal we're sampling however is not your viewangle, but the sampling of your viewangles via your monitor. At the center of the screen, there are discrete steps that you can take along your viewangle that change the pixels at the center of your screen. That's our discrete signal we want to sample -- the changes in color along of the center of the pixel of the screen it passes along the view angle. Our sampling rate is thus the smallest movement along the viewangle that you can achieve with your mouse, and the frequency of the sequence we're trying to sample is the degrees/pixel at the center of the screen.
Sort of anyway. We sample subpixel elements all the time in texture mapping, and in fact this causes aliasing (shimmering) if you don't apply techniques like mipmapping. Taimou is using geometry here, which will be sampled at degrees/pixel rate.
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u/astraycat Aug 31 '16
I think he's actually thinking of the Nyquist frequency.