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<!DOCTYPE html>
<html lang="zh">
<head>
<meta charset="utf-8" />
<base href="../../../" />
<script src="page.js"></script>
<link type="text/css" rel="stylesheet" href="page.css" />
</head>
<body>
<h1>三维矩阵([name])</h1>
<p class="desc">
一个表示3X3矩阵[link:https://en.wikipedia.org/wiki/Matrix_(mathematics) matrix].的类。
</p>
<h2>代码示例</h2>
<code>
const m = new Matrix3();
</code>
<h2>注意行优先列优先的顺序。</h2>
<p>
[page:set]()方法参数采用行优先[link:https://en.wikipedia.org/wiki/Row-_and_column-major_order#Column-major_order row-major],
而它们在内部是用列优先[link:https://en.wikipedia.org/wiki/Row-_and_column-major_order column-major]顺序存储在数组当中。<br /><br />
这意味着
<code>
m.set( 11, 12, 13,
21, 22, 23,
31, 32, 33 );
</code>
元素数组[page:.elements elements]将存储为:
<code>
m.elements = [ 11, 21, 31,
12, 22, 32,
13, 23, 33 ];
</code>
在内部,所有的计算都是使用列优先顺序进行的。然而,由于实际的排序在数学上没有什么不同,
而且大多数人习惯于以行优先顺序考虑矩阵,所以three.js文档以行为主的顺序显示矩阵。
请记住,如果您正在阅读源代码,您必须对这里列出的任何矩阵进行转置[link:https://en.wikipedia.org/wiki/Transpose transpose],以理解计算。
</p>
<h2>Constructor</h2>
<h3>[name]()</h3>
<p>
创建并初始化一个3X3的单位矩阵[link:https://en.wikipedia.org/wiki/Identity_matrix identity matrix].
</p>
<h2>属性(Properties)</h2>
<h3>[property:Array elements]</h3>
<p>
矩阵列优先[link:https://en.wikipedia.org/wiki/Row-_and_column-major_order column-major]列表。
</p>
<h2>方法(Methods)</h2>
<h3>[method:Matrix3 clone]()</h3>
<p>创建一个新的矩阵,元素 [page:.elements elements] 与该矩阵相同。</p>
<h3>[method:this copy]( [param:Matrix3 m] )</h3>
<p>将矩阵[page:Matrix3 m]的元素复制到当前矩阵中。</p>
<h3>[method:Float determinant]()</h3>
<p>
计算并返回矩阵的行列式[link:https://en.wikipedia.org/wiki/Determinant determinant] 。
</p>
<h3>[method:Boolean equals]( [param:Matrix3 m] )</h3>
<p>如果矩阵[page:Matrix3 m] 与当前矩阵所有对应元素相同则返回true。</p>
<h3>[method:this extractBasis]( [param:Vector3 xAxis], [param:Vector3 yAxis], [param:Vector3 zAxis] )</h3>
<p>
将该矩阵的基向量 [link:https://en.wikipedia.org/wiki/Basis_(linear_algebra) basis] 提取到提供的三个轴向中。如果该矩阵如下:
<code>
a, b, c,
d, e, f,
g, h, i
</code>
那么 [page:Vector3 xAxis], [page:Vector3 yAxis], [page:Vector3 zAxis] 将会被设置为:
<code>
xAxis = (a, d, g)
yAxis = (b, e, h)
zAxis = (c, f, i)
</code>
</p>
<h3>[method:this fromArray]( [param:Array array], [param:Integer offset] )</h3>
<p>
[page:Array array] - 用来存储设置元素数据的数组<br />
[page:Integer offset] - (可选参数) 数组的偏移量,默认值为 0。<br /><br />
使用基于列优先格式[link:https://en.wikipedia.org/wiki/Row-_and_column-major_order#Column-major_order column-major]的数组来设置该矩阵。
</p>
<h3>[method:this invert]()</h3>
<p>
将当前矩阵翻转为它的逆矩阵,使用 [link:https://en.wikipedia.org/wiki/Invertible_matrix#Analytic_solution analytic method] 解析方式。你不能对行或列为 0 的矩阵进行翻转,如果你尝试这样做,该方法将生成一个零矩阵。
</p>
<h3>[method:this getNormalMatrix]( [param:Matrix4 m] )</h3>
<p>
[page:Matrix4 m] - [page:Matrix4]<br /><br />
将这个矩阵设置为给定矩阵的正规矩阵[link:https://en.wikipedia.org/wiki/Normal_matrix normal matrix](左上角的3x3)。
正规矩阵是矩阵[page:Matrix4 m]的逆矩阵[link:https://en.wikipedia.org/wiki/Invertible_matrix inverse] 的转置[link:https://en.wikipedia.org/wiki/Transpose transpose]。
</p>
<h3>[method:this identity]()</h3>
<p>
将此矩阵重置为3x3单位矩阵:
<code>
1, 0, 0
0, 1, 0
0, 0, 1
</code>
</p>
<h3>[method:this makeRotation]( [param:Float theta] )</h3>
<p>
[page:Float theta] — Rotation angle in radians. Positive values rotate counterclockwise.<br /><br />
Sets this matrix as a 2D rotational transformation by [page:Float theta] radians.
The resulting matrix will be:
<code>
cos(&theta;) -sin(&theta;) 0
sin(&theta;) cos(&theta;) 0
0 0 1
</code>
</p>
<h3>[method:this makeScale]( [param:Float x], [param:Float y] )</h3>
<p>
[page:Float x] - the amount to scale in the X axis.<br />
[page:Float y] - the amount to scale in the Y axis.<br />
Sets this matrix as a 2D scale transform:
<code>
x, 0, 0,
0, y, 0,
0, 0, 1
</code>
</p>
<h3>[method:this makeTranslation]( [param:Float x], [param:Float y] )</h3>
<p>
[page:Float x] - the amount to translate in the X axis.<br />
[page:Float y] - the amount to translate in the Y axis.<br />
Sets this matrix as a 2D translation transform:
<code>
1, 0, x,
0, 1, y,
0, 0, 1
</code>
</p>
<h3>[method:this multiply]( [param:Matrix3 m] )</h3>
<p>将当前矩阵乘以矩阵[page:Matrix3 m]。</p>
<h3>[method:this multiplyMatrices]( [param:Matrix3 a], [param:Matrix3 b] )</h3>
<p>设置当前矩阵为矩阵[page:Matrix3 a] x 矩阵[page:Matrix3 b]。</p>
<h3>[method:this multiplyScalar]( [param:Float s] )</h3>
<p>当前矩阵所有的元素乘以该缩放值*s*</p>
<h3>[method:this set]( [param:Float n11], [param:Float n12], [param:Float n13], [param:Float n21], [param:Float n22], [param:Float n23], [param:Float n31], [param:Float n32], [param:Float n33] )</h3>
<p>
[page:Float n11] - 设置第一行第一列的值。<br />
[page:Float n12] - 设置第一行第二列的值。<br />
...<br />
...<br />
[page:Float n32] - 设置第三行第二列的值。<br />
[page:Float n33] - 设置第三行第三列的值。<br /><br />
使用行优先 [link:https://en.wikipedia.org/wiki/Row-_and_column-major_order row-major] 的格式来设置该矩阵。
</p>
<h3>[method:this premultiply]( [param:Matrix3 m] )</h3>
<p>将矩阵[page:Matrix3 m]乘以当前矩阵。</p>
<h3>[method:this setFromMatrix4]( [param:Matrix4 m] )</h3>
<p>根据参数 [page:Matrix4 m] 左上 3x3 的矩阵值,设置当前矩阵的值。</p>
<h3>[method:this setUvTransform]( [param:Float tx], [param:Float ty], [param:Float sx], [param:Float sy], [param:Float rotation], [param:Float cx], [param:Float cy] )</h3>
<p>
[page:Float tx] - x偏移量<br />
[page:Float ty] - y偏移量<br />
[page:Float sx] - x方向的重复比例<br />
[page:Float sy] - y方向的重复比例<br />
[page:Float rotation] - 旋转, 弧度。Positive values rotate counterclockwise<br />
[page:Float cx] - 旋转中心x<br />
[page:Float cy] - 旋转中心y<br /><br />
使用偏移,重复,旋转和中心点位置设置UV变换矩阵。
</p>
<h3>[method:Array toArray]( [param:Array array], [param:Integer offset] )</h3>
<p>
[page:Array array] - (可选参数) 存储矩阵元素的数组,如果未指定会创建一个新的数组。<br />
[page:Integer offset] - (可选参数) 存放矩阵元素数组的偏移量。<br /><br />
使用列优先[link:https://en.wikipedia.org/wiki/Row-_and_column-major_order#Column-major_order column-major]格式将此矩阵的元素写入数组中。
</p>
<h3>[method:this transpose]()</h3>
<p>将该矩阵转置[link:https://en.wikipedia.org/wiki/Transpose Transposes]。</p>
<h3>[method:this transposeIntoArray]( [param:Array array] )</h3>
<p>
[page:Array array] - 用于存储当前矩阵转置结果的数组。<br /><br />
将当前矩阵的转置[link:https://en.wikipedia.org/wiki/Transpose Transposes]存入给定的数组 array 中,但不改变当前矩阵,
并返回当前矩阵。
</p>
<h2>源码(Source)</h2>
<p>
[link:https://github.com/mrdoob/three.js/blob/master/src/[path].js src/[path].js]
</p>
</body>
</html>