Chapter 345: Euler

Core Idea

A class representing Euler angles.

Euler angles describe a rotational transformation by rotating an object on its various axes in specified amounts per axis, and a specified axis order.

Iterating through an instance will yield its components (x, y, z, order) in the corresponding order.

Key Concepts

isEuler : boolean (readonly): This flag can be used for type testing.
order : string: A string representing the order that the rotations are applied.
x : number: The angle of the x axis in radians.
y : number: The angle of the y axis in radians.
z : number: The angle of the z axis in radians.
DEFAULT_ORDER : string: The default Euler angle order.

Code Examples

const a = new THREE.Euler( 0, 1, 1.57, 'XYZ' );
const b = new THREE.Vector3( 1, 0, 1 );
b.applyEuler(a);

What it demonstrates: Typical usage of Euler.

Reference Tables

Constructor

Signature
`new Euler( x : number, y : number, z : number, order : string )`

Properties

Property	Description
`.isEuler : boolean (readonly)`	This flag can be used for type testing.
`.order : string`	A string representing the order that the rotations are applied.
`.x : number`	The angle of the x axis in radians.
`.y : number`	The angle of the y axis in radians.
`.z : number`	The angle of the z axis in radians.
`.DEFAULT_ORDER : string`	The default Euler angle order.

Methods

Method	Description
`.clone() : Euler`	Returns a new Euler instance with copied values from this instance.
`.copy( euler : Euler ) : Euler`	Copies the values of the given Euler instance to this instance.
`.equals( euler : Euler ) : boolean`	Returns `true` if this Euler instance is equal with the given one.
`.fromArray( array : Array.<number, number, number, ?string> ) : Euler`	Sets this Euler instance's components to values from the given array. The first three entries of the array are assign to the x,y and z components. An optional fourth entry defines the Euler order.
`.reorder( newOrder : string ) : Euler`	Resets the euler angle with a new order by creating a quaternion from this euler angle and then setting this euler angle with the quaternion and the new order.
`.set( x : number, y : number, z : number, order : string ) : Euler`	Sets the Euler components.
`.setFromQuaternion( q : Quaternion, order : string, update : boolean ) : Euler`	Sets the angles of this Euler instance from a normalized quaternion.
`.setFromRotationMatrix( m : Matrix4, order : string, update : boolean ) : Euler`	Sets the angles of this Euler instance from a pure rotation matrix.
`.setFromVector3( v : Vector3, order : string ) : Euler`	Sets the angles of this Euler instance from the given vector.
`.toArray( array : Array.<number, number, number, string>, offset : number ) : Array.<number, number, number, string>`	Writes the components of this Euler instance to the given array. If no array is provided, the method returns a new instance.

Key Takeaways

Most relevant properties: isEuler, order, x, y.
Key methods: clone, copy, equals, fromArray.

Connects To

Source: src/math/Euler.js