Unity 6.3 — 物理 Module Reference¶

// Default changed from 6 to 8 iterations
Physics.defaultSolverIterations = 8; // Check if relying on old behavior

// ✅ Unity 6: Improved Continuous Collision Detection (CCD)
rigidbody.collisionDetectionMode = CollisionDetectionMode.ContinuousDynamic;
// Better handling of fast-moving objects

// ✅ Best practice: Use AddForce, not direct velocity writes
Rigidbody rb = GetComponent<Rigidbody>();
rb.AddForce(Vector3.forward * 10f, ForceMode.Impulse);

// ❌ Avoid: Direct velocity assignment (can cause instability)
rb.velocity = new Vector3(0, 10, 0); // Only use when necessary

// Primitive colliders: Box, Sphere, Capsule (cheapest)
// Mesh colliders: Expensive, use only for static geometry

// ✅ Compound colliders (multiple primitives) > single mesh collider

// ✅ Non-allocating raycast
if (Physics.Raycast(origin, direction, out RaycastHit hit, maxDistance)) {
    Debug.Log($"Hit: {hit.collider.name}");
}

// ✅ Multiple hits (non-allocating)
RaycastHit[] results = new RaycastHit[10];
int hitCount = Physics.RaycastNonAlloc(origin, direction, results, maxDistance);
for (int i = 0; i < hitCount; i++) {
    Debug.Log($"Hit {i}: {results[i].collider.name}");
}

// ❌ Avoid: RaycastAll (allocates array every call)
RaycastHit[] hits = Physics.RaycastAll(origin, direction); // GC allocation!

// ✅ Use LayerMask to filter collisions
int layerMask = 1 << LayerMask.NameToLayer("Enemy");
Physics.Raycast(origin, direction, out RaycastHit hit, maxDistance, layerMask);

// ✅ Non-allocating version
Collider[] results = new Collider[10];
int count = Physics.OverlapSphereNonAlloc(center, radius, results);
for (int i = 0; i < count; i++) {
    // Process results[i]
}

// Useful for character controllers
if (Physics.SphereCast(origin, radius, direction, out RaycastHit hit, maxDistance)) {
    // Hit something with a sphere-shaped ray
}

void OnCollisionEnter(Collision collision) {
    // Triggered when collision starts
    Debug.Log($"Collided with {collision.gameObject.name}");

    // Access contact points
    foreach (ContactPoint contact in collision.contacts) {
        Debug.DrawRay(contact.point, contact.normal, Color.red, 2f);
    }
}

void OnTriggerEnter(Collider other) {
    // Trigger collider (Is Trigger = true)
    if (other.CompareTag("Pickup")) {
        Destroy(other.gameObject);
    }
}

CharacterController controller = GetComponent<CharacterController>();

// ✅ Move with collision detection
Vector3 move = transform.forward * speed * Time.deltaTime;
controller.Move(move);

// Apply gravity manually
if (!controller.isGrounded) {
    velocity.y += Physics.gravity.y * Time.deltaTime;
}
controller.Move(velocity * Time.deltaTime);

// Create: Assets > Create > Physic Material
// Assign to collider: Collider > Material

// PhysicMaterial settings:
// - Dynamic Friction: 0.6 (sliding friction)
// - Static Friction: 0.6 (starting friction)
// - Bounciness: 0.0 - 1.0
// - Friction Combine: Average, Minimum, Maximum, Multiply
// - Bounce Combine: Average, Minimum, Maximum, Multiply

FixedJoint joint = gameObject.AddComponent<FixedJoint>();
joint.connectedBody = otherRigidbody;

HingeJoint hinge = gameObject.AddComponent<HingeJoint>();
hinge.axis = Vector3.up; // Rotation axis
hinge.useLimits = true;
hinge.limits = new JointLimits { min = -90, max = 90 };

bool IsGrounded() {
    float rayLength = 0.1f;
    return Physics.Raycast(transform.position, Vector3.down, rayLength);
}

void ApplyExplosion(Vector3 explosionPos, float radius, float force) {
    Collider[] colliders = Physics.OverlapSphere(explosionPos, radius);
    foreach (Collider hit in colliders) {
        Rigidbody rb = hit.GetComponent<Rigidbody>();
        if (rb != null) {
            rb.AddExplosionForce(force, explosionPos, radius);
        }
    }
}

void OnDrawGizmos() {
    Gizmos.color = Color.red;
    Gizmos.DrawWireSphere(transform.position, detectionRadius);
}