Colliders not getting detected

I have created a demo scene in order to demonstrate my issue. As you can see in the images below I have 2 rings inside each other. I have added a script to the one on the right so that it will move at a medium speed when i press the WASD buttons. Each ring has a chain of sphere colliders as seen here:


Both spheres are identical (I prepared the 1st ring and duplicated it, then added the script to one of them). The problem is that when i move the ring on the right the rings almost immediately get separated, without any regard for the colliders:

As you can see in the image below the collision detection on both objects is Continuous Speculative. I understand that this is better for detecting angular forces than the Continuous detection.


Any ideas what I may be doing wrong and how I can fix this?

Hi dude !

make colliders bigger than now it will detect more and it not happened easily

The main issue is that you are moving in Update but collisions are tested in Fixed Update. Fixed updates happen 20 time a second by default. If your game is running 100fps then there might be 5 Updates for every 1 Fixed Update. In each update, you’ve moved the ring a little. By the time the Fixed Update runs, the rings are separated and no collision is detected.

The only 100% reliable solution I have found is to set RigidBody.velocity. Here is a very cut down version of the code I use:

using UnityEngine;

public class RB_Set_Velocity : MonoBehaviour
    [SerializeField] float playerMoveSpeed = 5;
    Rigidbody rb;
    Vector3 move;

    void Start()
        rb = GetComponent<Rigidbody>();

    void Update()
        float x = Input.GetAxisRaw("Horizontal");
        float z = Input.GetAxisRaw("Vertical");
        move = new Vector3(x, 0, z).normalized;

    void FixedUpdate()
        rb.velocity = move * playerMoveSpeed;

You may find recommendations not to set rb.velocity every frame and I understand why, though I have never found it to be a problem, either doing it in Update or FIxedUpdate.

For what it’s worth, I believe that the Unity Character Controller doesn’t use physics at all and manages collisions using Raycasts. Tells us something, I believe…