实施射击

1. For every wall's box surface enable the 7th bit of the Intersection Mask, and call it BulletIntersection.对于每一个墙的box曲面启用Intersection位掩码的第七位,并称之为BulletIntersection。

   

2. Create a new C# component and call it Projectile. Open your IDE and copy the following code. Save your code in the IDE to ensure it's automatic compilation on switching back to UnigineEditor.创建一个新的 C# 组件 并将其命名为 Projectile。 打开您的 IDE 并复制以下代码。 将您的代码保存在 IDE 中，以确保它在切换回 UnigineEditor 时自动编译。

   Projectile.cs

   using System;
   using System.Collections;
   using System.Collections.Generic;
   using Unigine;
   
   #if UNIGINE_DOUBLE
   using Vec3 = Unigine.dvec3;
   using Mat4 = Unigine.dmat4;
   using Scalar = System.Double;
   #else
   	using Vec3 = Unigine.vec3;
   	using Mat4 = Unigine.mat4;
   	using Scalar = System.Single;
   #endif 
   [Component(PropertyGuid = "AUTOGENERATED_GUID")] // <-- this line is generated automatically for a new component
   public class Projectile : Component
   {
   	// the speed of bullet movement
   	public float speed = 30.0f;
   
   	// asset file that contains the hit effect
   	public AssetLinkNode bulletHitEffect;
   
   	static WorldIntersectionNormal intersection;
   
   	void Init()
   	{
   		if (intersection == null)
   			intersection = new WorldIntersectionNormal();
   	}
   	
   	void Update()
   	{
   		Vec3 oldPos = node.WorldPosition;
   		vec3 dir = node.GetWorldDirection(MathLib.AXIS.Y);
   
   		// calculate the next position of the bullet
   		Vec3 newPos = oldPos + dir * speed * Game.IFps;
   		
   		// check intersection with other objects
   		Unigine.Object obj = World.GetIntersection(oldPos, newPos, ~0, intersection); //all mask bits are set to 1
   		if (obj)
   		{
   			// spawn a bullet at the hit point
   			Node hitEffect = bulletHitEffect.Load(intersection.Point);
   			// orient the effect towards the hit direction 
   			hitEffect.SetWorldDirection(intersection.Normal, vec3.UP, MathLib.AXIS.Y);
   
   			// add impulse to an object if it is a body rigid 
   			BodyRigid rb = obj.BodyRigid;
   			if (rb != null)
   			{
   				rb.Frozen = false;
   				rb.AddWorldImpulse(obj.WorldPosition, node.GetWorldDirection(MathLib.AXIS.Y) * speed);
   			}
   
   			// remove the bullet
   			node.DeleteLater();
   
   			return;
   		}
   		else
   		{
   			// move the bullet to a new position
   			node.WorldPosition = newPos;
   		}
   	}
   }

3. As the Life Time of the bullet runs out we should delete it by simply calling the DeleteLater() method. Create a new C# component and call it Destroy. Open your IDE, add the following code, save and switch to UnigineEditor to compile it.随着子弹的生命周期用完，我们应该通过简单地调用 DeleteLater() 方法来删除它。 创建一个新的 C# 组件 并将其命名为 Destroy。 打开您的IDE，添加以下代码，保存并切换到UnigineEditor进行编译。

   Destroy.cs

   using System;
   using System.Collections;
   using System.Collections.Generic;
   using Unigine;
   
   [Component(PropertyGuid = "AUTOGENERATED_GUID")] // <-- this line is generated automatically for a new component
   public class Destroy : Component
   {
   	[ShowInEditor][Parameter(Tooltip = "Object's lifetime")]
   	private float lifeTime = 1.0f;
   
   	private float startTime = 0.0f;
   
   	void Init()
   	{
   		// remember initialization time of an object
   		startTime = Game.Time;
   	}
   
   	void Update()
   	{
   		// wait until the lifetime ends and delete the object
   		if (Game.Time - startTime > lifeTime)
   			node.DeleteLater();
   	}
   }

4. Drag programming_quick_start\character\bullet\bullet.node from the Asset Browser into the Viewport and click Edit in the Reference section of the Parameters window to make modifications. Add a Destroy component to the child ObjectMeshStatic bullet node and set the Life Time to 5.0.将 programming_quick_start\character\bullet\bullet.node 节点从 Asset Browser 拖到 Viewport 并单击 Parameters 窗口的 Reference 部分中的 Edit 进行修改。 将 Destroy 组件添加到 ObjectMeshStatic bullet 子节点并设置 Life Time 到 5.0。

   

5. Next, drag the programming_quick_start\character\bullet_hit\bullet_hit.node from the Asset Browser into the Viewport, click Edit on the Parameters window, add the Destroy component to the bullet_hit's NodeDummy and to the LightOmni. Set Life Time values to 10.0 and 0.05 seconds respectively.接下来，将 Asset Browser 中的 programming_quick_start\character\bullet_hit\bullet_hit.node 拖到 Viewport 中，点击 Edit 在 Parameters 窗口中，将 Destroy 组件添加到 bullet_hit 的 NodeDummy 和 LightOmni。 将 Life Time 值分别设置为 10.0 和 0.05 秒。

   

6. Then select the bullet_hit Node Reference and click Apply in the Reference section to save all changes made to it.然后选择 bullet_hit Node Reference 并 在 Reference 部分中点击 Apply 保存对其所做的所有更改。

7. Then, add a Projectile component to the child ObjectMeshStatic bullet of the bullet Node Reference. Assign the bullet_hit node from the Asset Browser window to the Bullet Hit Effect field.然后,添加一个Projectile组件的子ObjectMeshStatic bullet bullet Node Reference。将bullet_hit节点从Asset Browser窗口分配给Bullet Hit Effect字段。

   

8. Now disable Intersection detection for the bullet to avoid the bullet detecting intersections with itself. Select the bullet_mat surface and uncheck the Intersection option for it.现在禁用子弹的碰撞测试避免子弹与自身检测十字路口。选择bullet_mat曲面和取消Intersection选项。
9. Save changes to the bullet Node Reference, by selecting it and clicking Apply in the Reference section or simply press Ctrl+S hotkey to save all changed assets.将更改保存到 bullet Node Reference，方法是选择它并单击 应用 在 Reference 部分，或简单地按 Ctrl+S 热键来保存所有更改的资源。
10. Now you can delete bullet and bullet_hit nodes from the world as we will spawn them via code.现在您可以从世界中删除bullet和bullet_hit，因为我们将通过代码生成它们。

Let's create special spawn nodes using Dummy Nodes with no visual representation. Their positions will be used as initial bullet positions.让我们使用 Dummy Node创建特殊刷出节点，但不使用视觉表示。它们的位置将被用作初始子弹的位置。

1. Select the robot Node Reference in the World Nodes window and click Edit in the Reference section of the Parameters window.在 World Nodes 窗口中选择 robot Node Reference 并在 Parameters 窗口的 Reference 部分中点击 Edit。
2. Right-click on the child robot ObjectMeshSkinned in the World Nodes window to add a child node. Choose Create->Node->Dummy and position it in the Viewport near the end of the left gun. The Y axis (green arrow) must point in the fire direction, since Unigine uses the right-handed Cartesian coordinate system.在 World Nodes 窗口中右键单击子 robot ObjectMeshSkinned 以添加子节点。 选择 Create->Node->Dummy 并将其放置在 Viewport 靠近左枪末端的位置。 Y 轴（绿色箭头）必须指向射击方向，因为 UNIGINE 使用 右手 笛卡尔坐标系。

3. Rename the Dummy Node as "left_bullet_spawn".将 Dummy Node 重命名为 "left_bullet_spawn"。

   

4. Create a spawn point for the right gun the same way and call it "right_bullet_spawn".以同样的方式为右枪创建一个刷出点，并将其命名为 "right_bullet_spawn"。

5. To spawn bullets at run-time via API on Right Mouse Button click, add the following code to the PlayerController component. We use AssetLinkNode to refer to the bullet node file. Save your code in an IDE to ensure it's automatic recompilation on switching back to UnigineEditor.要在运行时通过 API 在单击鼠标右键时生成子弹，请将以下代码添加到 PlayerController 组件。 我们使用 AssetLinkNode 来引用子弹节点文件。 将您的代码保存在 IDE 中，以确保在切换回 UnigineEditor 时自动重新编译。

   PlayerController.cs

   using System;
   using System.Collections;
   using System.Collections.Generic;
   using Unigine;
   
   #if UNIGINE_DOUBLE
   using Vec3 = Unigine.dvec3;
   using Mat4 = Unigine.dmat4;
   using Scalar = System.Double;
   #else
   	using Vec3 = Unigine.vec3;
   	using Mat4 = Unigine.mat4;
   	using Scalar = System.Single;
   #endif 
   [Component(PropertyGuid = "AUTOGENERATED_GUID")] // <-- this line is generated automatically for a new component
   public class PlayerController : Component
   {
   //========================== NEW - BEGIN ===============================
   	bool isNextLeft = false;
   
   	// mouse fire button 
   	public Input.MOUSE_BUTTON mouseFireKey = Input.MOUSE_BUTTON.RIGHT;
   
   	// asset file that contains the bullet
   	public AssetLinkNode bullet;
   
   	public Node leftSpawn, rightSpawn;
   //========================== NEW - END ===============================
   	Player player;
   
   	BodyRigid rigid;
   
   	Vec3 pos;
   
   	//a WorldIntersection object to store the information about the intersection
   	WorldIntersection intersection = new WorldIntersection();
   
   	void Init()
   	{
   		player = Game.Player; 
   
   		rigid = node.ObjectBodyRigid;
   		rigid.AngularScale = new vec3(0.0f, 0.0f, 0.0f); // restricting the rotation
   		rigid.LinearScale = new vec3(1.0f, 1.0f, 0.0f); // restricting Z movement
   		rigid.MaxLinearVelocity = 8.0f; // clamping the max linear velocity
   	}
   //========================== NEW - BEGIN ===============================
   	void Update() 
   	{
   		if (Input.IsMouseButtonDown(mouseFireKey) && bullet.IsFileExist)
   		{
   			// load the bullet and set its position 
   			if (isNextLeft)
   				bullet.Load(rightSpawn.WorldTransform);
   			else
   				bullet.Load(leftSpawn.WorldTransform);
   
   			// alternate between the left and the right gun
   			isNextLeft = !isNextLeft;
   		}
   
   		// press ESC button to close the game
   		if (Input.IsKeyDown(Input.KEY.ESC))
   		{
   			Engine.Quit();
   		}
   	}
   //========================== NEW - END ===============================
   	void UpdatePhysics() 
   	{
   		// forward
   		if (Input.IsKeyPressed(Input.KEY.W))
   			Move(player.GetWorldDirection(MathLib.AXIS.Y)); 
   
   		// backward
   		if (Input.IsKeyPressed(Input.KEY.S))
   			Move(player.GetWorldDirection(MathLib.AXIS.NY)); 
   		// left
   		if (Input.IsKeyPressed(Input.KEY.A))
   			Move(player.GetWorldDirection(MathLib.AXIS.NX)); 
   
   		// right
   		if (Input.IsKeyPressed(Input.KEY.D))
   			Move(player.GetWorldDirection(MathLib.AXIS.X)); 
   
   		// finding the positions of the cursor and the point moved 100 units away in the camera forward direction 
   		ivec2 mouse = Input.MousePosition;
   		Vec3 p0 = player.WorldPosition;
   		Vec3 p1 = p0 + new Vec3(player.GetDirectionFromMainWindow(mouse.x, mouse.y)) * 100; 
   
   		// casting a ray from p0 to p1 to find the first intersected object
   		Unigine.Object obj = World.GetIntersection(p0, p1, 1, intersection); // the first bit of the intersection mask is set to 1, the rest are 0s
   
   		// finding the intersection position, creating a transformation matrix to face this position and setting the transofrm matrix for the body preserving angular and linear velocities
   		if (obj)
   		{
   			pos = intersection.Point;
   			pos.z = rigid.Transform.Translate.z; // project the position vector to the Body Rigid pivot plane
   			Mat4 transform = MathLib.SetTo(rigid.Transform.Translate, pos, vec3.UP, MathLib.AXIS.Y);
   			rigid.SetPreserveTransform(transform);
   		}
   	}
   
   	// moving the rigid body with linear impulse in the specified direction
   	void Move(vec3 direction) 
   	{
   		//directon is a normalized camera axis vector 
   		rigid.AddLinearImpulse(direction);
   	}
   }

6. Drag left_bullet_spawn and right_bullet_spawn nodes to the corresponding fields of the PlayerController component of the robot node (ObjectMeshSkinned). And assign the bullet.node to the Bullet Path field.将 left_bullet_spawn 和 right_bullet_spawn 节点拖到相应的字段 PlayerController 组成部分robot 节点(ObjectMeshSkinned)。将 bullet.node 分配给 Bullet Path字段。

   

7. Save changes to the world, go to File->Save World or press Ctrl+S hotkey.拯救世界的变化,去File->Save World或者按Ctrl+S热键。