（四）Hololens Unity 开发之 凝视系统

学习源于官方文档 Gaze in Unity

笔记一部分是直接翻译官方文档，部分各人理解不一致的和一些比较浅显的保留英文原文

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HoloLens 有三大输入系统，凝视点、手势和声音 ~ 本文主要记录凝视系统的学习笔记 ~

（四）Hololens Unity 开发之 凝视系统

一、概述

Gaze is the first input mechanism on HoloLens. It's the first "G" in Gaze, Gesture, and Voice input models on HoloLens. However, there is no explicit API or Component exposing Gaze in Unity.

凝视系统是HoloLens的第一输入机制~（其实我觉得是借助了cardboard的交互模式），官文上有这么一句话 However, there is no explicit API or Component exposing Gaze in Unity. 凝视系统嘞~ 没有统一的API，所以只需要自己去实现就好~ 不是太复杂，下面是凝视系统的原理。

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二、凝视系统原理

原理很简单:射线碰撞检测 ，unity开发者都比较熟悉了~下面是官文中对射线碰撞的描述~不再翻译

Conceptually, Gaze is implemented by projecting a ray from the user's head where the HoloLens is, in the forward direction they are facing and determining what that ray collides with. In Unity, the user's head position and direction are exposed through the U