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<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8" />
<base href="../../../" />
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<body>
<h1>[name]</h1>
<p class="desc">
A class representing a 3x3 [link:https://en.wikipedia.org/wiki/Matrix_(mathematics) matrix].
</p>
<h2>Example</h2>
<code>
var m = new Matrix3();
</code>
<h2>A Note on Row-Major and Column-Major Ordering</h2>
<p>
The [page:set]() method takes arguments in [link:https://en.wikipedia.org/wiki/Row-_and_column-major_order#Column-major_order row-major]
order, while internally they are stored in the [page:.elements elements] array in column-major order.<br /><br />
This means that calling
<code>
m.set( 11, 12, 13,
21, 22, 23,
31, 32, 33 );
</code>
will result in the [page:.elements elements] array containing:
<code>
m.elements = [ 11, 21, 31,
12, 22, 32,
13, 23, 33 ];
</code>
and internally all calculations are performed using column-major ordering. However, as the actual ordering
makes no difference mathematically and most people are used to thinking about matrices in row-major order,
the three.js documentation shows matrices in row-major order. Just bear in mind that if you are reading the source
code, you'll have to take the [link:https://en.wikipedia.org/wiki/Transpose transpose] of any matrices outlined here to make sense of the calculations.
</p>
<h2>Constructor</h2>
<h3>[name]()</h3>
<p>
Creates and initializes the [name] to the 3x3
[link:https://en.wikipedia.org/wiki/Identity_matrix identity matrix].
</p>
<h2>Properties</h2>
<h3>[property:Array elements]</h3>
<p>
A [link:https://en.wikipedia.org/wiki/Row-_and_column-major_order column-major]
list of matrix values.
</p>
<h3>[property:Boolean isMatrix3]</h3>
<p>
Used to check whether this or derived classes are Matrix3s. Default is *true*.<br /><br />
You should not change this, as it used internally for optimisation.
</p>
<h2>Methods</h2>
<h3>[method:Array applyToBufferAttribute]( [param:BufferAttribute attribute] )</h3>
<p>
[page:BufferAttribute attribute] - An attribute of floats that represent 3D vectors.<br /><br />
Multiplies (applies) this matrix to every 3D vector in the [page:BufferAttribute attribute].
</p>
<h3>[method:Matrix3 clone]()</h3>
<p>Creates a new Matrix3 and with identical elements to this one.</p>
<h3>[method:this copy]( [param:Matrix3 m] )</h3>
<p>Copies the elements of matrix [page:Matrix3 m] into this matrix.</p>
<h3>[method:Float determinant]()</h3>
<p>
Computes and returns the
[link:https://en.wikipedia.org/wiki/Determinant determinant] of this matrix.
</p>
<h3>[method:Boolean equals]( [param:Matrix3 m] )</h3>
<p>Return true if this matrix and [page:Matrix3 m] are equal.</p>
<h3>[method:this fromArray]( [param:Array array], [param:Integer offset] )</h3>
<p>
[page:Array array] - the array to read the elements from.<br />
[page:Integer offset] - (optional) index of first element in the array. Default is 0.<br /><br />
Sets the elements of this matrix based on an array in
[link:https://en.wikipedia.org/wiki/Row-_and_column-major_order#Column-major_order column-major] format.
</p>
<h3>[method:this getInverse]( [param:Matrix3 m], [param:Boolean throwOnDegenerate] )</h3>
<p>
[page:Matrix3 m] - the matrix to take the inverse of.<br />
[page:Boolean throwOnDegenerate] - (optional) If true, throw an error if the matrix is degenerate (not invertible).<br /><br />
Set this matrix to the [link:https://en.wikipedia.org/wiki/Invertible_matrix inverse] of the passed matrix [page:Matrix3 m],
using the [link:https://en.wikipedia.org/wiki/Invertible_matrix#Analytic_solution analytic method].
If [page:Boolean throwOnDegenerate] is not set and the matrix is not invertible, set this to the 3x3 identity matrix.
</p>
<h3>[method:this getNormalMatrix]( [param:Matrix4 m] )</h3>
<p>
[page:Matrix4 m] - [page:Matrix4]<br /><br />
Sets this matrix as the upper left 3x3 of the [link:https://en.wikipedia.org/wiki/Normal_matrix normal matrix]
of the passed [page:Matrix4 matrix4]. The normal matrix is the [link:https://en.wikipedia.org/wiki/Invertible_matrix inverse] [link:https://en.wikipedia.org/wiki/Transpose transpose]
of the matrix [page:Matrix4 m].
</p>
<h3>[method:this identity]()</h3>
<p>
Resets this matrix to the 3x3 identity matrix:
<code>
1, 0, 0
0, 1, 0
0, 0, 1
</code>
</p>
<h3>[method:this multiply]( [param:Matrix3 m] )</h3>
<p>Post-multiplies this matrix by [page:Matrix3 m].</p>
<h3>[method:this multiplyMatrices]( [param:Matrix3 a], [param:Matrix3 b] )</h3>
<p>Sets this matrix to [page:Matrix3 a] x [page:Matrix3 b].</p>
<h3>[method:this multiplyScalar]( [param:Float s] )</h3>
<p>Multiplies every component of the matrix by the scalar value *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] - value to put in row 1, col 1.<br />
[page:Float n12] - value to put in row 1, col 2.<br />
...<br />
...<br />
[page:Float n32] - value to put in row 3, col 2.<br />
[page:Float n33] - value to put in row 3, col 3.<br /><br />
Sets the 3x3 matrix values to the given
[link:https://en.wikipedia.org/wiki/Row-_and_column-major_order row-major]
sequence of values.
</p>
<h3>[method:this premultiply]( [param:Matrix3 m] )</h3>
<p>Pre-multiplies this matrix by [page:Matrix3 m].</p>
<h3>[method:this setFromMatrix4]( [param:Matrix4 m] )</h3>
<p>Set this matrx to the upper 3x3 matrix of the Matrix4 [page:Matrix4 m].</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] - offset x<br />
[page:Float ty] - offset y<br />
[page:Float sx] - repeat x<br />
[page:Float sy] - repeat y<br />
[page:Float rotation] - rotation (in radians)<br />
[page:Float cx] - center x of rotation<br />
[page:Float cy] - center y of rotation<br /><br />
Sets the UV transform matrix from offset, repeat, rotation, and center.
</p>
<h3>[method:Array toArray]( [param:Array array], [param:Integer offset] )</h3>
<p>
[page:Array array] - (optional) array to store the resulting vector in. If not given a new array will be created.<br />
[page:Integer offset] - (optional) offset in the array at which to put the result.<br /><br />
Writes the elements of this matrix to an array in
[link:https://en.wikipedia.org/wiki/Row-_and_column-major_order#Column-major_order column-major] format.
</p>
<h3>[method:this transpose]()</h3>
<p>[link:https://en.wikipedia.org/wiki/Transpose Transposes] this matrix in place.</p>
<h3>[method:this transposeIntoArray]( [param:Array array] )</h3>
<p>
[page:Array array] - array to store the resulting vector in.<br /><br />
[link:https://en.wikipedia.org/wiki/Transpose Transposes] this matrix into the supplied array,
and returns itself unchanged.
</p>
<h2>Source</h2>
<p>
[link:https://github.com/mrdoob/three.js/blob/master/src/[path].js src/[path].js]
</p>
</body>
</html>
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