Mouse or look movement smooth but character movement stutter

[Steveggz]

When either playing with the mouse and keyboard or xbox controller the look movement is butter smooth but as soon as I move the character the screen has a very apparent microstutter which is even more obvious when using the controller and walking slowly. It then looks like the screen is trembling. This is altogether even more obvious when playing at higher framerates like 120 or 144fps.

Can this be fixed by the developers?

BTW, I've tried with v-sync on and off. I've also tried it in exclusive fullscreen by adding -window-mode exclusive. And -force-d3d9. Nothing seems to get rid of that microstutter.

I'm using Windows 7 pro, 2500K @ 4.5 Ghx, GTX 670 ftw.

[Rubel]

This is actually a very complex issue! The core of the problem is that our game has two different types of pixels; we have macro pixels, which is the large scale pixels our art is drawn at, and screen pixels, which has to do with what resolution your monitor runs at. Typically macro pixels are made up of 4x4 screen pixels (at 1080p) since our game's art is drawn at 270p.

All of the art in our game lives on the "pixel grid" at the macro pixel scale, which keeps our pixels crisp and helps us prevent rotating macro pixels or having macro pixels partially overlap other macro pixels. (As you can probably tell by now, we care a lot about our pixels!) We chose to allow the camera to move in screen pixels instead of macro pixels however, because it makes camera motion feel much smoother and generally improves game feel.

Since the camera tracks your mouse cursor AND your player, we had to make a decision about the player; do we track their macro pixel position or their screen pixel position? Tracking the player's screen position allows the world to move smoothly but causes the player to jitter back and forth in the center of the screen as you walk; if we track in macro pixels, then the camera is jumping a whole macro pixel at a time when your character finally steps into the next pixel, which makes the whole world stutter slightly but leaves your character in the exact same spot on your screen.

Which of these two is better is very personal. I prefer letting the character jerk and having the world move smoothly, but the majority of our team feels that keeping the character from jittering looks and feels better, so that's the direction we went. I'd like to expose this as an option to the player (I believe you're only the second person who's commented on this motion jitter, so this isn't high priority right now) and I'd love to see which people prefer!

(Also, yes, we did consider allowing the player to move off the pixel grid, which would allow us to move the player and the world smoothly; this would cause some other visual artifacts that we aren't thrilled with though, and more importantly, would be difficult to do now since we've build so many things that work specifically on the macro pixel scale, particularly our physics engine!)