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First person camera judder with rigidbody based characters
I've put together a rigidbody based first person controller system for the project I'm working on. Basically the issue that I have is that I get awful levels of judder when rotating the camera whilst moving at the same time moving the player. Here is a video of it for context. The judder is shown first, followed by what it should be like if I could get it to work properly:
https://drive.google.com/file/d/0BwmJXNLk6lQILTBiYlVfV0QyUUE/view?usp=sharing
This issue has actually been posted about multiple times, but all of the answers that I've seen either haven't worked for my situation or have fixes that at least from what I can tell have unnecessary side effects. So far I've tried and failed with:
Adding Time.deltaTime to some of the calculations in the script below.
Recording the deltaTime inside fixed update as a variable and using that as the smooth time in the SmoothDamp function.
Setting the rigidbody to interpolate, extrapolate and even changing the collision detection to continuous/ continuous dynamic.
Interestingly this is what has worked:
Moving the camera input from LateUpdate or Update to FixedUpdate. This actually fixes the problem (probably as they're both in sync?), however I'm aware that FixedUpdate should only be used for physics work. Coupled with this causing the camera rotation speed to depend on the fixed time step, doing this isn't really practical if I have differing frame rates used on an end user's machine.
Decreasing the fixed time step to 1/60 (0.0166666) completely eradicates the problem. However this is at the expense of more physics calculations and causes the same issue mentioned above. That and it's limited to 60FPS.
Here is my camera script to get more context. I can post up the rigidbody movement controller if need be. Any other ideas would be appreciated for fixing this as I'm out of luck at this point:
https://drive.google.com/file/d/0BwmJXNLk6lQILTBiYlVfV0QyUUE/view?usp=sharing
using UnityEngine;
using System.Collections;
/// <summary>
/// Handles our first person camera motion
/// </summary>
[RequireComponent(typeof(CameraUtilities))]
public class FirstPersonCameraController : MonoBehaviour
{
#region Variables
public Camera camera;
public Rigidbody rigidbody;
public float clampValue = 90f;
public float lookSensitivity = 5f;
public float smoothingInertia = 0.05f;
public Vector2 mouseInput;
public Vector2 mouseAbsolute;
public Vector2 smoothedRotation;
public Vector2 currentSmoothedVelocity;
private Quaternion xRotation;
private Quaternion yRotation;
private Quaternion cameraStartDirection;
private Quaternion rigidbodyStartDirection;
#endregion
#region Singleton
private static FirstPersonCameraController _instance;
public static FirstPersonCameraController instance
{
get
{
if (_instance == null)
{
_instance = new FirstPersonCameraController();
}
return _instance;
}
}
#endregion
/// <summary>
/// Processes input from the mouse to calculate the camera movement
/// </summary>
private void CameraInput()
{
// get raw mouse input
mouseInput = new Vector2(Input.GetAxisRaw("Mouse X"), (Input.GetAxisRaw("Mouse Y")));
mouseInput = Vector2.Scale(mouseInput, new Vector2(lookSensitivity,
lookSensitivity));
// smooth the mouse input and increment
smoothedRotation.x = Mathf.SmoothDamp(smoothedRotation.x, mouseInput.x,
ref currentSmoothedVelocity.x, smoothingInertia);
smoothedRotation.y = Mathf.SmoothDamp(smoothedRotation.y, mouseInput.y,
ref currentSmoothedVelocity.y, smoothingInertia);
mouseAbsolute += smoothedRotation;
// clamp the mouse data y axis so we can't back flip
mouseAbsolute.y = Mathf.Clamp(mouseAbsolute.y, -clampValue, clampValue);
// calculate our finished axis rotations
xRotation = Quaternion.AngleAxis(-mouseAbsolute.y, Vector3.right);
yRotation = Quaternion.AngleAxis(mouseAbsolute.x, rigidbody.transform.up);
// apply axis rotations
camera.transform.localRotation = cameraStartDirection * xRotation;
rigidbody.transform.localRotation = yRotation * rigidbodyStartDirection;
}
private void Awake()
{
if (_instance == null)
{
_instance = this;
}
else
{
Destroy(this);
}
}
private void Start()
{
// get the rigidbody and camera for rotating
camera = CameraUtilities.GetMainCamera();
rigidbody = Player.instance.GetRigidBody();
// get our starting directions
cameraStartDirection = camera.transform.localRotation;
rigidbodyStartDirection = rigidbody.transform.localRotation;
// clear them all to zero
currentSmoothedVelocity = smoothedRotation = mouseAbsolute = Vector3.zero;
}
/// <summary>
/// Switching this to FixedUpdate fixes judder
/// </summary>
private void Update()
{
CameraInput();
}
}
Sorry to bump, but any ideas with this? This is still bugging me unfortunately.
Answer by aditya · Dec 07, 2016 at 12:46 PM
Always keep camera movement code in same monobehaviour method as your rigidbody movement code ... like if you are moving your rigid body in FixedUpdate method than put your camera movement code too in FixedUpdate if you still find some jitter then try to change your rigidbody interpolation to Interpolate if it still not working that well then try to put your camera code to LateUpdate
Sorry, but I've already tried all of that. The only thing that did work was keeping it all in FixedUpdate though like you mentioned. However, as I said above that isn't really ideal.
In any case though, FixedUpdate is for physics, not camera motion.
Of-course brother i know that fixedupdate is for physics ... but here i m talking about putting the code in same methods because physics calls are slower (by default) then camera rendering calls ... whatever if nothing is working for just try to lower your timestamp in physics manager, but this needs some processing power so be careful ... or just check your other scripts that might be interfering with your camera movement and object movement
The timestep solution is one that I already tried as well. Whilst that works, also not ideal as per what you and I have said.
I would just not do anything with fixedupdate or anything and just go straight to lateupdate. It works so far for me...
I guess the jittering is occuring from the fact that your rigidbody motion is calculating after the camera script, causing the camera script to be one frame behind the rigidbody. LateUpdate itself should fix that
Nope, putting the camera motion code in LateUpdate doesn't work. Did you use my script for that? If so, perhaps there is something else amiss in another script.
From the video... I actually think it might be an error where the rotation is being applied after the movement, It looks like it might be a source of error
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