# BoneLookController Attitude limitation problem **URL:** \ **Category:** Questions\ **Tags:** bone\ **Created:** [May 26, 2023, 5:52am UTC](https://forum.babylonjs.com/t/bonelookcontroller-attitude-limitation-problem/41151 "2023-05-26T05:52:59Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![xiehangyun](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/xiehangyun/32/30777_2.png) [@xiehangyun](https://forum.babylonjs.com/u/xiehangyun)\ **Post date:** [May 26, 2023, 5:52am UTC](https://forum.babylonjs.com/t/bonelookcontroller-attitude-limitation-problem/41151/1 "2023-05-26T05:52:59Z")
[gaze | Babylon.js Playground (babylonjs.com)](https://playground.babylonjs.com/#1B1PUZ#145) In this case, I wanted to set Yaw less than -160 and greater than 160 to limit the lateral deviation of the eyeball, but I couldn’t? The BoneLookController receives the minimum and maximum values of the options passed in, if they are greater than the minimum and less than the maximum. ---
**Author:** ![carolhmj](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/carolhmj/32/25918_2.png) [@carolhmj](https://forum.babylonjs.com/u/carolhmj)\ **Post date:** [May 26, 2023, 3:59pm UTC](https://forum.babylonjs.com/t/bonelookcontroller-attitude-limitation-problem/41151/2 "2023-05-26T15:59:00Z")
hmmm you want to limit the angle of the eye bones so the pupils never disappear right? @bghgary @Evgeni_Popov any idea how can this be done? ---
**Author:** ![xiehangyun](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/xiehangyun/32/30777_2.png) [@xiehangyun](https://forum.babylonjs.com/u/xiehangyun)\ **Post date:** [May 26, 2023, 5:53pm UTC](https://forum.babylonjs.com/t/bonelookcontroller-attitude-limitation-problem/41151/3 "2023-05-26T17:53:05Z")
Yes, I would like to limit the pupil yaw value, yaw \< -160 || yaw \> 160, but now its rules don’t seem to allow. Modifying adjustYaw didn’t get the effect I wanted, causing the pitch to move in the opposite direction. ---
**Author:** ![Evgeni\_Popov](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/evgeni_popov/32/4432_2.png) [@Evgeni\_Popov](https://forum.babylonjs.com/u/Evgeni_Popov)\ **Post date:** [May 27, 2023, 10:48am UTC](https://forum.babylonjs.com/t/bonelookcontroller-attitude-limitation-problem/41151/4 "2023-05-27T10:48:13Z")
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**Author:** ![Evgeni\_Popov](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/evgeni_popov/32/4432_2.png) [@Evgeni\_Popov](https://forum.babylonjs.com/u/Evgeni_Popov)\ **Post date:** [May 27, 2023, 1:03pm UTC](https://forum.babylonjs.com/t/bonelookcontroller-attitude-limitation-problem/41151/5 "2023-05-27T13:03:56Z")
In your case, you need the yaw value to be either between [160°,180°] or [-180°,-160°]. Or, if using the absolute value of yaw, it is simply [160°,180°]. I have created a PR that allows you to use the absolute value of yaw instead of yaw when checking the constraints: > > > See https://forum.babylonjs.com/t/bonelookcontroller-attitude-limitation-problem…/41151 When the PR is merged, this PG will work (look for `useAbsoluteValueForYaw` in the `options`): > **[Babylon.js Playground](https://playground.babylonjs.com/#1B1PUZ%23140)** > > Babylon.js playground is a live editor for Babylon.js WebGL 3D scenes ---
**Author:** ![Evgeni\_Popov](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/evgeni_popov/32/4432_2.png) [@Evgeni\_Popov](https://forum.babylonjs.com/u/Evgeni_Popov)\ **Post date:** [May 27, 2023, 1:03pm UTC](https://forum.babylonjs.com/t/bonelookcontroller-attitude-limitation-problem/41151/6 "2023-05-27T13:03:59Z")
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**Author:** ![xiehangyun](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/xiehangyun/32/30777_2.png) [@xiehangyun](https://forum.babylonjs.com/u/xiehangyun)\ **Post date:** [May 27, 2023, 3:07pm UTC](https://forum.babylonjs.com/t/bonelookcontroller-attitude-limitation-problem/41151/7 "2023-05-27T15:07:16Z")
![image](https://us1.discourse-cdn.com/flex024/uploads/babylonjs/original/3X/e/b/eb423c68764ffcfae9ee17dd40d3f484b5f8627f.png) Thanks for the reply, and the PR, but there are still issues with using absolute values. I use a diagram to describe the problems that may arise. Because the yaw value is a ring, can we determine whether the range of the yaw limit is above or below the ring by judging the size of min versus max? Here are some of my thoughts. ---
**Author:** ![Evgeni\_Popov](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/evgeni_popov/32/4432_2.png) [@Evgeni\_Popov](https://forum.babylonjs.com/u/Evgeni_Popov)\ **Post date:** [May 27, 2023, 3:35pm UTC](https://forum.babylonjs.com/t/bonelookcontroller-attitude-limitation-problem/41151/8 "2023-05-27T15:35:35Z")
The PR will make your PG work the way you want it to, so that’s at least a step in the right direction 🙂 . I think the most general solution would be to be able to define several ranges for the yaw constraint (and pitch, for that matter) - [160°,180°] + [-180°,-160°] in your case. That’s what I tried at first, but I’m not familiar enough with the code and how it works, so I tried the “absolute value” route and was pleased to see that it worked! ---
**Author:** ![xiehangyun](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/xiehangyun/32/30777_2.png) [@xiehangyun](https://forum.babylonjs.com/u/xiehangyun)\ **Post date:** [May 27, 2023, 4:39pm UTC](https://forum.babylonjs.com/t/bonelookcontroller-attitude-limitation-problem/41151/9 "2023-05-27T16:39:00Z")
> [@Evgeni\_Popov](#): > > I think the most general solution would be to be able to define several ranges for the yaw constraint (and pitch, for that matter) - [160°,180°] + [-180°,-160°] in your case This should be the perfect solution.