Unity基础篇：射线检测Physics.Raycast相关功能整合。

我们先看射线的相关文档。

public static bool RayCast(Vector3 origin, Vector3 direction, float maxDistance = Mathf.Infinity, int layerMask = DefaultRaycastLayers, QueryTriggerInteraction queryTriggerInteraction = QueryTriggerInteraction.UseGlobal);

public static bool Raycast(Vector3 origin, Vector3 direction, out RaycastHit hitInfo, float maxDistance = Mathf.Infinity, int layerMask = DefaultRaycastLayers, QueryTriggerInteraction queryTriggerInteraction = QueryTriggerInteraction.UseGlobal);

public static bool Raycast(Ray ray, float maxDistance = Mathf.Infinity, int layerMask = DefaultRaycastLayers, QueryTriggerInteraction queryTriggerInteraction = QueryTriggerInteraction.UseGlobal);

public static bool Raycast(Ray ray, out RaycastHit hitInfo, float maxDistance = Mathf.Infinity, int layerMask = DefaultRaycastLayers, QueryTriggerInteraction queryTriggerInteraction = QueryTriggerInteraction.UseGlobal);

Parameters 参数

origin	The starting point of the ray in world coordinates. 在世界坐标，射线的起始点。
direction	The direction of the ray. 射线的方向。
distance	The length of the ray. 射线的长度。
layermask	A Layer mask that is used to selectively ignore colliders when casting a ray. 投射射线，选择投射的层蒙版。
queryTriggerInteraction	Specifies whether this query should hit Triggers. 指定是否查询碰到触发器。

ray	The starting point and direction of the ray. 射线的起点和方向

hitInfo

If true is returned, hitInfo will contain more information about where the collider was hit (See Also: RaycastHit).
hitInfo将包含碰到器碰撞的更多信息。

RaycastHit 射线投射碰撞信息

struct in UnityEngine

Description 描述

Structure used to get information back from a raycast.

该结构用来获取射线投射返回的信息。

Variables 变量

barycentricCoordinate	The barycentric coordinate of the triangle we hit. 碰到的三角形的重心坐标。
collider	The Collider that was hit. 碰到的碰撞器。
distance	The distance from the ray's origin to the impact point. 从射线的原点到触碰点的距离。
lightmapCoord	The uv lightmap coordinate at the impact point. 在触碰点的UV光照贴图的坐标。
normal	The normal of the surface the ray hit. 射线触碰表面的法线。
point	The impact point in world space where the ray hit the collider. 在世界坐标空间，射线碰到碰撞器的接触点。
rigidbody	The Rigidbody of the collider that was hit. If the collider is not attached to a rigidbody then it is null. 碰到的该碰撞器上的刚体。如果碰撞器上没有附加刚体，那么返回null。
textureCoord	The uv texture coordinate at the impact point. 在触碰点的UV纹理坐标。
textureCoord2	The secondary uv texture coordinate at the impact point. 在接触点处的第二套UV纹理坐标。
transform	The Transform of the rigidbody or collider that was hit. 碰到的该刚体或碰撞器的变换。
triangleIndex	The index of the triangle that was hit. 碰到的三角形的索引。

Returns 返回

bool True when the ray intersects any collider, otherwise false.

当光线投射与任何碰撞器交叉时为真，否则为假。

缺省参数：1.layerMask参数缺省为DefaultRaycastLayers，

2.distance被缺省为正无穷，

3. queryTriggerInteraction 被缺省为QueryTriggerInteraction.UseGlobal

什么意思呢？我们来看

简单来说就是，枚举为Ignore时，所有含碰撞器的物体，都将被射线检测忽略。为UseGlobal时反之。

先来个最简单的Demo

由于我们是以空格键来发射射线，所以Debug.DrawLine(transform.position, hit.transform.position);画得线我截不到。见谅。

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