Question by awplays49 · Sep 19, 2015 at 02:45 AM · physics gravity jitter jittering jittery

Gravity controller is buggy

This is a controller I scripted:

 using UnityEngine;
 using System.Collections;
 
 [RequireComponent (typeof (PlayerControllerHandler))]
 public class PlayerController : MonoBehaviour {
 
     public float gravity;
     public float moveSpeed;
     private Vector3 velocity;
     private float currentGravity;
     private PlayerControllerHandler pch;
     
     void Start () {
         pch = GetComponent <PlayerControllerHandler> ();
     }
     
     void Update () {
         currentGravity = velocity.y;
         velocity = Vector3.zero;
         velocity.y = currentGravity;
         if (Input.GetKey (KeyCode.W))
         {
             velocity += transform.forward;
         }
         else if (Input.GetKey (KeyCode.A))
         {
             velocity -= transform.right;
         }
         if (Input.GetKey (KeyCode.D))
         {
             velocity += transform.right;
         }
         else if (Input.GetKey (KeyCode.S))
         {
             velocity -= transform.forward;
         }
         velocity.y += gravity * Time.deltaTime;
         pch.Move (velocity * Time.deltaTime);
     }
 }

And this is a controller handler:

 using UnityEngine;
 using System.Collections;
 
 [RequireComponent (typeof (CapsuleCollider))]
 public class PlayerControllerHandler : MonoBehaviour {
 
     public LayerMask collisionMask;
     private CapsuleCollider cc;
     public int collisions;
     
     void Start () {
         cc = GetComponent <CapsuleCollider> ();
     }
     
     public void Move (Vector3 velocity) {
         Collide (ref velocity);
         transform.Translate (velocity);
     }
     
     void Collide (ref Vector3 velocity) {
         RaycastHit hit;
         Vector3 point1 = transform.position + Vector3.up * cc.height / 4;
         Vector3 point2 = transform.position + Vector3.up * cc.height * 0.75f;
         float rayDistance = Vector3.Distance (transform.position, transform.position + velocity);
         if (Physics.CapsuleCast (point1, point2, cc.radius, velocity, out hit, rayDistance))
         {
             Debug.Log (hit.point.y);
             if (Mathf.Abs (transform.position.x - hit.point.x) < Mathf.Abs (velocity.x))
             {
                 collisions ++;
                 velocity.x = transform.position.x - hit.point.x;
             }
             if (Mathf.Abs (transform.position.y - hit.point.y) < Mathf.Abs (velocity.y))
             {
                 collisions ++;
                 velocity.y = transform.position.y - hit.point.y;
             }
             if (Mathf.Abs (transform.position.z - hit.point.z) < Mathf.Abs (velocity.z))
             {
                 collisions ++;
                 velocity.z = transform.position.z - hit.point.z;
             }        
         }
     }
 }

Set the capsule collider to radius 1, height 4. y axis. And youll see he jittters higher and higher. Until hes floating.

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awplays49 · Sep 19, 2015 at 02:10 PM 0

It just doesn't make sense

awplays49 · Sep 19, 2015 at 03:04 PM 0

I've been staring at a screen for hours now. I think I'll leave it to the community of Unity Answers to help me take this one.

Glurth · Sep 19, 2015 at 03:43 PM 0

Shot in the dark: It doesn't look like you are taking cc.center, nor cc.direction into account when computing point1 and point2. If either of these are not what you are assuming, that could be a problem.

awplays49 · Sep 19, 2015 at 03:56 PM 0

@Glurth well, now I have this and it doesn't register until I'm below the ground.

 using UnityEngine;
 using System.Collections;
 
 [RequireComponent (typeof (CapsuleCollider))]
 public class PlayerControllerHandler : MonoBehaviour {
 
     public LayerMask collisionMask;
     private CapsuleCollider cc;
     public int collisions;
     
     void Start () {
         cc = GetComponent <CapsuleCollider> ();
     }
     
     public void Move (Vector3 velocity) {
         Collide (ref velocity);
         transform.Translate (velocity);
     }
     
     void Collide (ref Vector3 velocity) {
         RaycastHit hit;
         Vector3 point1 = transform.position + cc.center + Vector3.down * cc.height / 4;
         Vector3 point2 = transform.position + cc.center + Vector3.up * cc.height / 4;
         Debug.Log (point1 + " " + point2);
         float rayDistance = Vector3.Distance (transform.position, transform.position + velocity);
         if (Physics.CapsuleCast (point1, point2, cc.radius, velocity, out hit, rayDistance))
         {
             if (Mathf.Abs (transform.position.x - hit.point.x) < Mathf.Abs (velocity.x))
             {
                 collisions ++;
                 velocity.x = transform.position.x - hit.point.x;
             }
             if (Mathf.Abs (transform.position.y - hit.point.y) < Mathf.Abs (velocity.y))
             {
                 collisions ++;
                 velocity.y = transform.position.y - hit.point.y;
             }
             if (Mathf.Abs (transform.position.z - hit.point.z) < Mathf.Abs (velocity.z))
             {
                 collisions ++;
                 velocity.z = transform.position.z - hit.point.z;
             }        
         }
     }
 }

Glurth awplays49 · Sep 19, 2015 at 04:09 PM 0

Ah! You are also not taking transform.scale, nor rotation into account, for the points. (http://docs.unity3d.com/ScriptReference/Transform.TransformPoint.html)

 Vector3 point1 = transform.TransformPoint( cc.center + Vector3.down * (cc.height -cc.radius) );

Side note: I see you take transform.position into account when computing the ray distance, though it is not actually needed there:

 float rayDistance = Vector3.Distance (transform.position, transform.position + velocity);

is equivalent to

  float rayDistance = Vector3.Distance (Vector3.zero, Vector3.zero + velocity);

is equivalent to

 float rayDistance = velocity.magnitude;

awplays49 · Sep 19, 2015 at 04:12 PM 0

I'm not sure what you meant, but What I want to do is predict where my character will be next frame, and if its gonna be in a wall, move right against the wall.

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