Challenge
Differentiate center/edge/tip impacts without overhead and preserve arc feel with an extensible base (dynamic sweet spot).
Multi‑Point Racket
Rigidbody capsules follow targets; tips accelerate more, delivering energy proportional to impact point.
public class RacketPhysicsProxy : MonoBehaviour {
Transform followTarget; Rigidbody rb; [SerializeField] float sensitivity = 100f;
void Awake(){ rb = GetComponent(); }
public void SetFollowTarget(Transform t){ followTarget = t; transform.SetPositionAndRotation(t.position, t.rotation); }
void FixedUpdate(){
Vector3 dest = followTarget.position; Vector3 v = (dest - rb.position) * sensitivity;
rb.velocity = v; rb.rotation = followTarget.rotation;
}
} Magnus Spin
Spin computed (dot + cross). Continuous Magnus force curves trajectory (topspin/slice) with stability.
[RequireComponent(typeof(Rigidbody))]
public class TennisBallPhysics : MonoBehaviour {
Rigidbody rb; [SerializeField] float magnusCoefficient = 0.05f;
void Start(){ rb = GetComponent(); }
void FixedUpdate(){
if (rb.velocity.magnitude > 0.1f){
Vector3 magnus = magnusCoefficient * Vector3.Cross(rb.angularVelocity, rb.velocity);
rb.AddForce(magnus);
}
}
public void ApplySpinOnHit(Vector3 racketVelocity, Vector3 hitNormal){
float spinAmount = Vector3.Dot(racketVelocity, hitNormal);
Vector3 axis = Vector3.Cross(rb.velocity, racketVelocity).normalized;
rb.angularVelocity = axis * spinAmount * 20f;
}
} Results
Localized impact, predictable spin, <0.3ms/frame cost, ready for extensions (haptics / elastic deformation).