1 files changed, 4 insertions, 1 deletions
diff --git a/Assets/uGUI-2017.1/UnityEngine.UI/EventSystem/Raycasters/PhysicsRaycaster.cs b/Assets/uGUI-2017.1/UnityEngine.UI/EventSystem/Raycasters/PhysicsRaycaster.cs
index 2b4bea3..c7d431c 100644
--- a/Assets/uGUI-2017.1/UnityEngine.UI/EventSystem/Raycasters/PhysicsRaycaster.cs
+++ b/Assets/uGUI-2017.1/UnityEngine.UI/EventSystem/Raycasters/PhysicsRaycaster.cs
@@ -3,6 +3,8 @@ using UnityEngine.UI;
 
 namespace UnityEngine.EventSystems
 {
+    //c 投射3D物体的相机挂这个脚本
+
     /// <summary>
     /// Simple event system using physics raycasts.
     /// </summary>
@@ -66,7 +68,7 @@ namespace UnityEngine.EventSystems
         {
             ray = eventCamera.ScreenPointToRay(eventData.position);
             // compensate far plane distance - see MouseEvents.cs
-            float projectionDirection = ray.direction.z;
+            float projectionDirection = ray.direction.z; // ray.direction是归一化了的
             distanceToClipPlane = Mathf.Approximately(0.0f, projectionDirection)
                 ? Mathf.Infinity
                 : Mathf.Abs((eventCamera.farClipPlane - eventCamera.nearClipPlane) / projectionDirection);
@@ -78,6 +80,7 @@ namespace UnityEngine.EventSystems
             if (eventCamera == null || !eventCamera.pixelRect.Contains(eventData.position))
                 return;
 
+            // 根据触摸数据拿到射线
             Ray ray;
             float distanceToClipPlane;
             ComputeRayAndDistance(eventData, out ray, out distanceToClipPlane);