How do i prevent my player from walking through mesh collider

Question

I have a character being moved using rigidbody.moveposition and I have an floating lowpoly island with a mesh collider. When my player walks into a steep slope or a wall, it passes right through. I assume this is because the mesh collider isn't thick enough but there must be a pretty simple fix. If anyone knows how to fix this it would be much appreciated.

Here's the code for the movement of my character.

private void Movement()
{
    if (AnimController.GetInteger("AnimPar") != 3)
    {
        if (Input.GetKey(KeyCode.LeftShift))
        {
            walkSpeed = initialWalkSpeed * 2;
        }
        else
        {
            walkSpeed = initialWalkSpeed;
        }


        if ((Forward && Right) || (Forward && Left) || (Backward && Right) || (Backward && Left))
        {
            walkSpeed *= .7f;
        }

        if (Forward)
        {
            Delta += transform.forward * walkSpeed * Time.deltaTime;
        }

        if (Backward)
        {
            Delta -= transform.forward * walkSpeed * Time.deltaTime;
        }

        if (Right)
        {
            Delta += transform.right * walkSpeed * Time.deltaTime;
        }

        if (Left)
        {
            Delta -= transform.right * walkSpeed * Time.deltaTime;

        }



        rb.MovePosition(new Vector3(Delta.x, transform.position.y, Delta.z));
    }
}

Answer 1

I think you should use AddForce instead of SetPosition on your rigid body. Setting the position will place the body at the new position, but adding a force will cause the body to move through the simulation steps. Make sure you use continuous collision detection.