PiHead What is a response curve, and how do you tune it for head tracking?
Sensitivity multiplies your head movement by a single number. At 2.0×, turning your head 10° turns the game 20°, and 40° turns it 80°. Most of the time that's enough, but it has one problem: the small twitches around the center get multiplied by the same amount. The view shakes while you watch the road or the instruments, and when you lower sensitivity, looking to the edges gets harder. A response curve lets you separate the two.
What the curve shows
Clicking Response Curves… in the app opens a window where the horizontal axis shows the real angle of your head and the vertical axis shows the angle sent to the game. A straight line means the game turns exactly in proportion to your head. Where the line flattens, movement slows down there; where it gets steeper, it speeds up.
There's also a green dot in the window. It shows where your head is on the curve right now. Turning your head and watching which part of the curve the dot moves through is very helpful while tuning.
In the app, the curve is applied before sensitivity. In other words, the curve sets the shape of the movement and sensitivity scales the result.
The presets
| Curve | How it behaves | When to choose it |
|---|---|---|
| Linear | The view turns exactly in proportion to your head. | For getting started and for finding the problem. |
| Soft center | Damps small movements while you look ahead, back to normal at the edges. | Games where you watch instruments or the road for a long time. |
| Quick look | Calm in the center, opens up quickly once you turn your head a little. | Games where you often check mirrors, your six or over your shoulder. |
Tuning your own curve
You usually get the best result by starting from a preset and making small changes on top of it. This is the order we follow:
- Start with the linear curve. First set the sensitivity so that a comfortable head turn reaches the widest angle you want in the game.
- Find where the problem is. Is there jitter in the center, or is it hard to reach the edges? Watch the green dot to see which part of the curve the problem is in.
- Change only that area. If the center shakes, pull the point near the center down a little. If the edges are hard to reach, raise the outer points.
- Test it in the game. Play for a minute or two and look again. Making changes in small steps makes it easier to see what works.
You can drag the points with the mouse. Double-clicking an empty spot adds a new point, and right-clicking a point removes it. Working with only a few points makes tuning easier. Three or four points are enough for most games.
Why the curve is the same in both directions
The curves in the app work the same to the right and left, and up and down. When you change a point on the right side, the left side changes the same way. We did this on purpose, because when the two directions differ, the view feels like it's being pulled to one side as you turn back to the center. The curve is also always calculated to keep increasing. No matter how you push the points, turning your head further never makes the view turn back.
A separate curve for each axis
You can use separate curves for yaw, pitch and roll. Yaw is usually the one people tune most, since looking left and right is the widest movement. Soft center works well for pitch, so small head movements forwards and backwards don't shake the view. Most people keep roll low or leave it alone.
Examples by game
- Truck and car sims: Quick look for yaw, Soft center for pitch. Checking mirrors gets easier, and the view stays calm on a straight road. More in our ETS2 post.
- Civil flying: Soft center for both axes. The view doesn't shake while you read instruments.
- Combat flying: Quick look for yaw and slightly higher sensitivity. A small head turn is enough to check your six.
Curves are saved as part of the profile. If you create a profile for each game, each game gets its own curve too. You can save a profile you like to a file with Export… and share it with a friend.