Quaternion 四元数

# Quaternion 四元数

Struct

Quaternions are used to represent rotations.

四元数用于表示旋转。

They are compact, don't suffer from gimbal lock and can easily be
interpolated. Unity internally uses Quaternions to represent all rotations.

它们是紧凑的，不会出现万向节锁并且能够很容易被插值。Unity 内使用 Quaternion 表示所有旋转。

However, they are based on complex numbers and are not easy to understand
intuitively. Thus you almost never access or modify individual Quaternion
components (x,y,z,w); most often you would just take existing rotations (e.g.
from the [Transform](../Transform/Transform.html)) and use them to
construct new rotations (e.g. to smoothly interpolate between two rotations).
The Quaternion functions that you use 99% of the time (The other functions are
only for exoctic uses) [Quaternion.LookRotation](Quaternion.LookRotation.html), [Quaternion.Angle](Quaternion.Angle.html), [Quaternion.Euler](Quaternion.Euler.html), [Quaternion.Slerp](Quaternion.Slerp.html), [Quaternion.FromToRotation](Quaternion.FromToRotation.html), [Quaternion.identity](Quaternion.identity.html)

然而，它们基于复数的并不容易被直观地理解，因此你没有必要访问或修改单个 Quaternion 组件(x,y,z,w)；通常你只需把现有的旋转（例如，来自 Transform）并使用它们来构造新的旋转（例如，在两个旋转间平滑地插值）。四元数函数你 99% 的时间你会使用它（其他函数仅额外使用）[Quaternion.LookRotation](Quaternion.LookRotation.html), [Quaternion.Angle](Quaternion.Angle.html), [Quaternion.Euler](Quaternion.Euler.html), [Quaternion.Slerp](Quaternion.Slerp.html), [Quaternion.FromToRotation](Quaternion.FromToRotation.html), [Quaternion.identity](Quaternion.identity.html)。

You can use [Quaternion.operator
*](Quaternion.operator_multiply.html) to rotate one rotation by another, or to rotate a vector by a
rotation.

你可以使用 [Quaternion.operator
*](Quaternion.operator_multiply.html)由另一个四元数来旋转一个旋转角度，或由一个旋转角度来旋转一个向量。

### Variables**变量**

* [x](Quaternion.x.html)
  X component of the Quaternion. Don't modify this directly
  unless you know quaternions inside out.
  四元数的 X 组件。不要直接修改这个，除非你很了解四元数。

* [y](Quaternion.y.html)
  Y component of the Quaternion. Don't modify this directly
  unless you know quaternions inside out.
  四元数的 Y 组件。不要直接修改这个，除非你很了解四元数。
* [z](Quaternion.z.html)
  Z component of the Quaternion. Don't modify this directly
  unless you know quaternions inside out.
  四元数的 Z 组件。不要直接修改这个，除非你很了解四元数。
* [w](Quaternion.w.html)
  W component of the Quaternion. Don't modify this directly
  unless you know quaternions inside out.
  四元数的 W 组件。不要直接修改这个，除非你很了解四元数。
* [this [int
  index]](Quaternion.Index_operator.html)
  Access the x, y, z, w components using [0], [1], [2], [3]
  respectively.
  分别使用 [0]、[1]、 [2]、 [3]，访问 x、y、z、w 组件。
* [eulerAngles](Quaternion.eulerAngles.html)
  Returns the euler angle representation of the
  rotation.
  返回表示旋转的欧拉角度。

### Constructors**构造器**

* [Quaternion](Quaternion.Quaternion.html)
  Constructs new Quaternion with given x,y,z,w
  components.
  用给定的 x、y、z、w 组件，构造新的四元数。

### Functions**函数**

* [ToAngleAxis](Quaternion.ToAngleAxis.html)
  Converts a rotation to angle-axis
  representation.
  转换一个旋转用“角-轴”表示。
* [SetFromToRotation](Quaternion.SetFromToRotation.html)
  Creates a rotation which rotates from fromDirection to
  toDirection.
  创建一个从 fromDirection 到 toDirection 的旋转。
* [SetLookRotation](Quaternion.SetLookRotation.html)
  Creates a rotation that looks along forward with the the
  head upwards along upwards
  创建一个旋转，沿着 forward（z 轴）并且头部沿着 up（y 轴）的约束注视。
* [ToString](Quaternion.ToString.html)
  Returns a nicely formatted string of the
  Quaternion
  返回一个格式化好的四元数字符串。

### Class Variables**类变量**

* [identity](Quaternion.identity.html)
  The identity rotation (Read Only). This quaternion
  corresponds to "no rotation": the
  object
  返回恒等式旋转（只读）。这个四元数对于“无旋转”：这个物体完全对齐于世界或父轴。

### Class Functions**类函数**

* [operator
  *](Quaternion.operator_multiply.html)
  Combines rotations lhs and rhs.
  组合旋转 lhs 和 rhs。
* [operator ==](Quaternion.operator_eq.html)
  Are two quaternions equal to each other?
  两个四元数相等？
* [operator !=](Quaternion.operator_ne.html)
  Are two quaternions different from each
  other?
  两个四元数是不相等的？
* [Dot](Quaternion.Dot.html)
  The dot product between two rotations.
  两个旋转之间的点乘。
* [AngleAxis](Quaternion.AngleAxis.html)
  Creates a rotation which rotates angle degrees around
  axis.
  绕 axis 轴旋转 angle，创建一个旋转。
* [FromToRotation](Quaternion.FromToRotation.html)
  Creates a rotation which rotates from fromDirection to
  toDirection.
  从 fromDirection 到 toDirection 创建一个旋转。
* [LookRotation](Quaternion.LookRotation.html)
  Creates a rotation that looks along forward with the the
  head upwards along upwards
  创建一个旋转，沿着 forward（z 轴）并且头部沿着 upwards（y 轴）的约束注视。
* [Slerp](Quaternion.Slerp.html)
  Spherically interpolates from towards to by
  t.
  球形插值，通过 t 值 from 向 to 之间插值。
* [Lerp](Quaternion.Lerp.html)
  Interpolates from towards to by t and normalizes the result
  afterwards.
  通过 t 值 from 向 to 之间插值，并且规范化结果。
* [RotateTowards](Quaternion.RotateTowards.html)
  Rotates a rotation from towards to.
  旋转一个角度从 from 向 to。
* [Inverse](Quaternion.Inverse.html)
  Returns the Inverse of rotation.
  返回反向的旋转。
* [Angle](Quaternion.Angle.html)
  Returns the angle in degrees between two rotations a and
  b.
  返回 a 和 b 两者之间的角度。
* [Euler](Quaternion.Euler.html)
  Returns a rotation that rotates z degrees around the z
  axis, x degrees around the x axis, and y degrees around the y axis (in that
  order).
  返回一个旋转角度，绕 z 轴旋转 z 度，绕 x 轴旋转 x 度，绕 y 轴旋转 y 度（像这样的顺序）。