• Products
  • Solutions
  • Made with Unity
  • Learning
  • Support & Services
  • Community
  • Asset Store
  • Get Unity

UNITY ACCOUNT

You need a Unity Account to shop in the Online and Asset Stores, participate in the Unity Community and manage your license portfolio. Login Create account
  • Blog
  • Forums
  • Answers
  • Evangelists
  • User Groups
  • Beta Program
  • Advisory Panel

Navigation

  • Home
  • Products
  • Solutions
  • Made with Unity
  • Learning
  • Support & Services
  • Community
    • Blog
    • Forums
    • Answers
    • Evangelists
    • User Groups
    • Beta Program
    • Advisory Panel

Unity account

You need a Unity Account to shop in the Online and Asset Stores, participate in the Unity Community and manage your license portfolio. Login Create account

Language

  • Chinese
  • Spanish
  • Japanese
  • Korean
  • Portuguese
  • Ask a question
  • Spaces
    • Default
    • Help Room
    • META
    • Moderators
    • Topics
    • Questions
    • Users
    • Badges
  • Home /
  • Help Room /
avatar image
0
Question by DiegoMazo · Dec 24, 2019 at 02:37 AM · fpsbulletfpstutorial

Please help me with this scrip

This is a bullet code, which I understand in certain parts. What I do not understand is how this code achieves that regardless of the position of the weapon the bullets always go to the center of the screen.

 using System.Collections.Generic;
 using UnityEngine;
 
 [RequireComponent(typeof(ProjectileBase))]
 public class ProjectileStandard : MonoBehaviour
 {
     [Header("General")]
     [Tooltip("Radius of this projectile's collision detection")]
     public float radius = 0.01f;
     [Tooltip("Transform representing the root of the projectile (used for accurate collision detection)")]
     public Transform root;
     [Tooltip("Transform representing the tip of the projectile (used for accurate collision detection)")]
     public Transform tip;
     [Tooltip("LifeTime of the projectile")]
     public float maxLifeTime = 5f;
     [Tooltip("VFX prefab to spawn upon impact")]
     public GameObject impactVFX;
     [Tooltip("LifeTime of the VFX before being destroyed")]
     public float impactVFXLifetime = 5f;
     [Tooltip("Offset along the hit normal where the VFX will be spawned")]
     public float impactVFXSpawnOffset = 0.1f;
     [Tooltip("Clip to play on impact")]
     public AudioClip impactSFXClip;
     [Tooltip("Layers this projectile can collide with")]
     public LayerMask hittableLayers = -1;
 
     [Header("Movement")]
     [Tooltip("Speed of the projectile")]
     public float speed = 20f;
     [Tooltip("Downward acceleration from gravity")]
     public float gravityDownAcceleration = 0f;
     [Tooltip("Distance over which the projectile will correct its course to fit the intended trajectory (used to drift projectiles towards center of screen in First Person view). At values under 0, there is no correction")]
     public float trajectoryCorrectionDistance = -1;
     [Tooltip("Determines if the projectile inherits the velocity that the weapon's muzzle had when firing")]
     public bool inheritWeaponVelocity = false;
 
     [Header("Damage")]
     [Tooltip("Damage of the projectile")]
     public float damage = 40f;
     [Tooltip("Area of damage. Keep empty if you don<t want area damage")]
     public DamageArea areaOfDamage;
 
     [Header("Debug")]
     [Tooltip("Color of the projectile radius debug view")]
     public Color radiusColor = Color.cyan * 0.2f;
 
     ProjectileBase m_ProjectileBase;
     Vector3 m_LastRootPosition;
     Vector3 m_Velocity;
     bool m_HasTrajectoryOverride;
     float m_ShootTime;
     Vector3 m_TrajectoryCorrectionVector;
     Vector3 m_ConsumedTrajectoryCorrectionVector;
     List<Collider> m_IgnoredColliders;
 
     const QueryTriggerInteraction k_TriggerInteraction = QueryTriggerInteraction.Collide;
 
     private void OnEnable()
     {
         m_ProjectileBase = GetComponent<ProjectileBase>();
         DebugUtility.HandleErrorIfNullGetComponent<ProjectileBase, ProjectileStandard>(m_ProjectileBase, this, gameObject);
 
         m_ProjectileBase.onShoot += OnShoot;
 
         Destroy(gameObject, maxLifeTime);
     }
 
     void OnShoot()
     {
         m_ShootTime = Time.time;
         m_LastRootPosition = root.position;
         m_Velocity = transform.forward * speed;
         m_IgnoredColliders = new List<Collider>();
         transform.position += m_ProjectileBase.inheritedMuzzleVelocity * Time.deltaTime;
 
         // Ignore colliders of owner
         Collider[] ownerColliders = m_ProjectileBase.owner.GetComponentsInChildren<Collider>();
         m_IgnoredColliders.AddRange(ownerColliders);
 
         // Handle case of player shooting (make projectiles not go through walls, and remember center-of-screen trajectory)
         PlayerWeaponsManager playerWeaponsManager = m_ProjectileBase.owner.GetComponent<PlayerWeaponsManager>();
         if(playerWeaponsManager)
         {
             m_HasTrajectoryOverride = true;
 
             Vector3 cameraToMuzzle = (playerWeaponsManager.weaponCamera.transform.position - m_ProjectileBase.initialPosition);
 
             m_TrajectoryCorrectionVector = Vector3.ProjectOnPlane(cameraToMuzzle, playerWeaponsManager.weaponCamera.transform.forward);
             if (trajectoryCorrectionDistance == 0)
             {
                 transform.position += m_TrajectoryCorrectionVector;
                 m_ConsumedTrajectoryCorrectionVector = m_TrajectoryCorrectionVector;
             }
             else if (trajectoryCorrectionDistance < 0)
             {
                 m_HasTrajectoryOverride = false;
             }
             
             if (Physics.Raycast(playerWeaponsManager.weaponCamera.transform.position, cameraToMuzzle.normalized, out RaycastHit hit, cameraToMuzzle.magnitude, hittableLayers, k_TriggerInteraction))
             {
                 if (IsHitValid(hit))
                 {
                     OnHit(hit.point, hit.normal, hit.collider);
                 }
             }
         }
     }
 
     void Update()
     {
         // Move
         transform.position += m_Velocity * Time.deltaTime;
         if (inheritWeaponVelocity)
         {
             transform.position += m_ProjectileBase.inheritedMuzzleVelocity * Time.deltaTime;
         }
 
         // Drift towards trajectory override (this is so that projectiles can be centered 
         // with the camera center even though the actual weapon is offset)
         if (m_HasTrajectoryOverride && m_ConsumedTrajectoryCorrectionVector.sqrMagnitude < m_TrajectoryCorrectionVector.sqrMagnitude)
         {
             Vector3 correctionLeft = m_TrajectoryCorrectionVector - m_ConsumedTrajectoryCorrectionVector;
             float distanceThisFrame = (root.position - m_LastRootPosition).magnitude;
             Vector3 correctionThisFrame = (distanceThisFrame / trajectoryCorrectionDistance) * m_TrajectoryCorrectionVector;
             correctionThisFrame = Vector3.ClampMagnitude(correctionThisFrame, correctionLeft.magnitude);
             m_ConsumedTrajectoryCorrectionVector += correctionThisFrame;
 
             // Detect end of correction
             if(m_ConsumedTrajectoryCorrectionVector.sqrMagnitude == m_TrajectoryCorrectionVector.sqrMagnitude)
             {
                 m_HasTrajectoryOverride = false;
             }
 
             transform.position += correctionThisFrame;
         }
 
         // Orient towards velocity
         transform.forward = m_Velocity.normalized;
 
         // Gravity
         if (gravityDownAcceleration > 0)
         {
             // add gravity to the projectile velocity for ballistic effect
             m_Velocity += Vector3.down * gravityDownAcceleration * Time.deltaTime;
         }
 
         // Hit detection
         {
             RaycastHit closestHit = new RaycastHit();
             closestHit.distance = Mathf.Infinity;
             bool foundHit = false;
 
             // Sphere cast
             Vector3 displacementSinceLastFrame = tip.position - m_LastRootPosition;
             RaycastHit[] hits = Physics.SphereCastAll(m_LastRootPosition, radius, displacementSinceLastFrame.normalized, displacementSinceLastFrame.magnitude, hittableLayers, k_TriggerInteraction);
             foreach (var hit in hits)
             {
                 if (IsHitValid(hit) && hit.distance < closestHit.distance)
                 {
                     foundHit = true;
                     closestHit = hit;
                 }
             }
 
             if (foundHit)
             {
                 // Handle case of casting while already inside a collider
                 if(closestHit.distance <= 0f)
                 {
                     closestHit.point = root.position;
                     closestHit.normal = -transform.forward;
                 }
 
                 OnHit(closestHit.point, closestHit.normal, closestHit.collider);
             }
         }
 
         m_LastRootPosition = root.position;
     }
 
     bool IsHitValid(RaycastHit hit)
     {
         // ignore hits with an ignore component
         if(hit.collider.GetComponent<IgnoreHitDetection>())
         {
             return false;
         }
 
         // ignore hits with triggers that don't have a Damageable component
         if(hit.collider.isTrigger && hit.collider.GetComponent<Damageable>() == null)
         {
             return false;
         }
 
         // ignore hits with specific ignored colliders (self colliders, by default)
         if (m_IgnoredColliders.Contains(hit.collider))
         {
             return false;
         }
 
         return true;
     }
 
     void OnHit(Vector3 point, Vector3 normal, Collider collider)
     { 
         // damage
         if (areaOfDamage)
         {
             // area damage
             areaOfDamage.InflictDamageInArea(damage, point, hittableLayers, k_TriggerInteraction, m_ProjectileBase.owner);
         }
         else
         {
             // point damage
             Damageable damageable = collider.GetComponent<Damageable>();
             if (damageable)
             {
                 damageable.InflictDamage(damage, false, m_ProjectileBase.owner);
             }
         }
 
         // impact vfx
         if (impactVFX)
         {
             GameObject impactVFXInstance = Instantiate(impactVFX, point + (normal * impactVFXSpawnOffset), Quaternion.LookRotation(normal));
             if (impactVFXLifetime > 0)
             {
                 Destroy(impactVFXInstance.gameObject, impactVFXLifetime);
             }
         }
 
         // impact sfx
         if (impactSFXClip)
         {
             AudioUtility.CreateSFX(impactSFXClip, point, AudioUtility.AudioGroups.Impact, 1f, 3f);
         }
 
         // Self Destruct
         Destroy(this.gameObject);
     }
 
     private void OnDrawGizmosSelected()
     {
         Gizmos.color = radiusColor;
         Gizmos.DrawSphere(transform.position, radius);
     }
 }

Comment
Add comment
10 |3000 characters needed characters left characters exceeded
▼
  • Viewable by all users
  • Viewable by moderators
  • Viewable by moderators and the original poster
  • Advanced visibility
Viewable by all users

0 Replies

· Add your reply
  • Sort: 

Your answer

Hint: You can notify a user about this post by typing @username

Up to 2 attachments (including images) can be used with a maximum of 524.3 kB each and 1.0 MB total.

Welcome to Unity Answers

The best place to ask and answer questions about development with Unity.

To help users navigate the site we have posted a site navigation guide.

If you are a new user to Unity Answers, check out our FAQ for more information.

Make sure to check out our Knowledge Base for commonly asked Unity questions.

If you are a moderator, see our Moderator Guidelines page.

We are making improvements to UA, see the list of changes.



Follow this Question

Answers Answers and Comments

230 People are following this question.

avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image

Related Questions

Help with Level Endpoint 0 Answers

Fps tutorial? I would like to bring in my character 0 Answers

Vertical gun movement exaggerated 0 Answers

How to make a bullet whistle next to a player in Unity? 0 Answers

Object position/rotation after animation has finished to play. 1 Answer

  • Anonymous
  • Sign in
  • Create
  • Ask a question
  • Spaces
  • Default
  • Help Room
  • META
  • Moderators
  • Explore
  • Topics
  • Questions
  • Users
  • Badges