<!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8" /> <base href="../../../" /> <script src="page.js"></script> <link type="text/css" rel="stylesheet" href="page.css" /> </head> <body> <h1>[name]</h1> <p class="desc"> A class representing a 3x3 [link:https://en.wikipedia.org/wiki/Matrix_(mathematics) matrix]. </p> <h2>Code Example</h2> <code> const 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> <h2>Methods</h2> <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 extractBasis]( [param:Vector3 xAxis], [param:Vector3 yAxis], [param:Vector3 zAxis] )</h3> <p> Extracts the [link:https://en.wikipedia.org/wiki/Basis_(linear_algebra) basis] of this matrix into the three axis vectors provided. If this matrix is: <code> a, b, c, d, e, f, g, h, i </code> then the [page:Vector3 xAxis], [page:Vector3 yAxis], [page:Vector3 zAxis] will be set to: <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] - 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 invert]()</h3> <p> Inverts this matrix, using the [link:https://en.wikipedia.org/wiki/Invertible_matrix#Analytic_solution analytic method]. You can not invert with a determinant of zero. If you attempt this, the method produces a zero matrix instead. </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 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(θ) -sin(θ) 0 sin(θ) cos(θ) 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>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 rotate]( [param:Float theta] )</h3> <p>Rotates this matrix by the given angle (in radians).</p> <h3>[method:this scale]( [param:Float sx], [param:Float sy] )</h3> <p>Scales this matrix with the given scalar values.</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 matrix 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. Positive values rotate counterclockwise<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 translate]( [param:Float tx], [param:Float ty] )</h3> <p>Translates this matrix by the given scalar values.</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>