# modeling/src/maths/plane/transform.js

``````const mat4 = require('../mat4')
const vec3 = require('../vec3')

const fromPoints = require('./fromPoints')
const flip = require('./flip')

/**
* Transform the given plane using the given matrix
*
* @param {plane} out - receiving plane
* @param {plane} plane - plane to transform
* @param {mat4} matrix - matrix to transform with
* @return {plane} out
* @alias module:modeling/maths/plane.transform
*/
const transform = (out, plane, matrix) => {
const ismirror = mat4.isMirroring(matrix)
// get two vectors in the plane:
const r = vec3.orthogonal(vec3.create(), plane)
const u = vec3.cross(r, plane, r)
const v = vec3.cross(vec3.create(), plane, u)
// get 3 points in the plane:
let point1 = vec3.fromScalar(vec3.create(), plane[3])
vec3.multiply(point1, point1, plane)
let point2 = vec3.add(vec3.create(), point1, u)
let point3 = vec3.add(vec3.create(), point1, v)
// transform the points:
point1 = vec3.transform(point1, point1, matrix)
point2 = vec3.transform(point2, point2, matrix)
point3 = vec3.transform(point3, point3, matrix)
// and create a new plane from the transformed points:
fromPoints(out, point1, point2, point3)
if (ismirror) {
// the transform is mirroring so flip the plane
flip(out, out)
}
return out
}

module.exports = transform
``````