Class Quat

A quaternion representing rotation in 3D space. Quaternions are typically used to represent rotations in 3D applications, offering advantages over Euler angles including no gimbal lock and more efficient interpolation.

Index

Constructors

constructor

Properties

w x y z IDENTITY ZERO

Constructors

constructor

new Quat(x?: number, y?: number, z?: number, w?: number): Quat
Creates a new Quat instance.
Parameters
- Optionalx: number
  The x value. Defaults to 0.
- Optionaly: number
  The y value. Defaults to 0.
- Optionalz: number
  The z value. Defaults to 0.
- Optionalw: number
  The w value. Defaults to 1.
Returns Quat
Example
```
const q1 = new pc.Quat(); // defaults to 0, 0, 0, 1
const q2 = new pc.Quat(1, 2, 3, 4);
```
- Defined in src/core/math/quat.js:47
new Quat(arr: number[]): Quat
Creates a new Quat instance.
Parameters
- arr: number[]
  The array to set the vector values from.
Returns Quat
Example
```
const q = new pc.Quat([1, 2, 3, 4]);
```
- Defined in src/core/math/quat.js:47

Properties

w

w: number

The w component of the quaternion.

x

x: number

The x component of the quaternion.

y

y: number

The y component of the quaternion.

z

z: number

The z component of the quaternion.

`Static` `Readonly`IDENTITY

IDENTITY: Quat = ...

A constant quaternion set to [0, 0, 0, 1] (the identity). Represents no rotation.

`Static` `Readonly`ZERO

ZERO: Quat = ...

A constant quaternion set to [0, 0, 0, 0].

Methods

clone

clone(): Quat
Returns an identical copy of the specified quaternion.

Returns Quat
A new quaternion identical to this one.
Example
```
const q = new pc.Quat(-0.11, -0.15, -0.46, 0.87);
const qclone = q.clone();

console.log("The result of the cloning is: " + qclone.toString());
```
- Defined in src/core/math/quat.js:95

copy

copy(rhs: Quat): Quat
Copies the contents of a source quaternion to a destination quaternion.
Parameters
- rhs: Quat
  The quaternion to be copied.
Returns Quat
Self for chaining.
Example
```
const src = new pc.Quat();
const dst = new pc.Quat();
dst.copy(src);
console.log("The two quaternions are " + (src.equals(dst) ? "equal" : "different"));
```
- Defined in src/core/math/quat.js:132

dot

dot(other: Quat): number
Calculates the dot product of two quaternions.
Parameters
- other: Quat
  The quaternion to calculate the dot product with.
Returns number
The dot product of the two quaternions.
Example
```
const a = new pc.Quat(1, 0, 0, 0);
const b = new pc.Quat(0, 1, 0, 0);
console.log("Dot product: " + a.dot(b)); // Outputs 0
```
- Defined in src/core/math/quat.js:151

equals

equals(rhs: Quat): boolean
Reports whether two quaternions are equal.
Parameters
- rhs: Quat
  The quaternion to be compared against.
Returns boolean
True if the quaternions are equal and false otherwise.
Example
```
const a = new pc.Quat();
const b = new pc.Quat();
console.log("The two quaternions are " + (a.equals(b) ? "equal" : "different"));
```
- Defined in src/core/math/quat.js:165

equalsApprox

equalsApprox(rhs: Quat, epsilon?: number): boolean
Reports whether two quaternions are equal using an absolute error tolerance.
Parameters
- rhs: Quat
  The quaternion to be compared against.
- Optionalepsilon: number = 1e-6
  The maximum difference between each component of the two quaternions. Defaults to 1e-6.
Returns boolean
True if the quaternions are equal and false otherwise.
Example
```
const a = new pc.Quat();
const b = new pc.Quat();
console.log("The two quaternions are approximately " + (a.equalsApprox(b, 1e-9) ? "equal" : "different"));
```
- Defined in src/core/math/quat.js:181

fromArray

fromArray(
arr: number[] | ArrayBufferView<ArrayBufferLike>,
offset?: number,
): Quat
Set the values of the quaternion from an array.
Parameters
- arr: number[] | ArrayBufferView<ArrayBufferLike>
  The array to set the quaternion values from.
- Optionaloffset: number = 0
  The zero-based index at which to start copying elements from the array. Default is 0.
Returns Quat
Self for chaining.
Example
```
const q = new pc.Quat();
q.fromArray([20, 10, 5, 0]);
// q is set to [20, 10, 5, 0]
```
- Defined in src/core/math/quat.js:797

getAxisAngle

getAxisAngle(axis: Vec3): number
Gets the rotation axis and angle for a given quaternion. If a quaternion is created with setFromAxisAngle, this method will return the same values as provided in the original parameter list OR functionally equivalent values.
Parameters
- axis: Vec3
  The 3-dimensional vector to receive the axis of rotation.
Returns number
Angle, in degrees, of the rotation.
Example
```
const q = new pc.Quat();
q.setFromAxisAngle(new pc.Vec3(0, 1, 0), 90);
const v = new pc.Vec3();
const angle = q.getAxisAngle(v);
// Outputs 90
console.log(angle);
// Outputs [0, 1, 0]
console.log(v.toString());
```
- Defined in src/core/math/quat.js:205

getEulerAngles

getEulerAngles(eulers?: Vec3): Vec3
Converts this quaternion to Euler angles, specified in degrees. The decomposition uses an intrinsic XYZ order, representing the angles required to achieve the quaternion's orientation by rotating sequentially: first around the X-axis, then around the newly transformed Y-axis, and finally around the resulting Z-axis.
Parameters
- Optionaleulers: Vec3 = ...
  An optional 3-dimensional vector to receive the calculated Euler angles (output parameter). If not provided, a new Vec3 object will be allocated and returned.
Returns Vec3
The 3-dimensional vector holding the Euler angles in degrees. This will be the same object passed in as the eulers parameter (if one was provided).
Example
```
const q = new pc.Quat();
q.setFromAxisAngle(pc.Vec3.UP, 90);
const e = new pc.Vec3();
q.getEulerAngles(e);
// Outputs [0, 90, 0]
console.log(e.toString());
```
- Defined in src/core/math/quat.js:247

invert

invert(src?: Quat): Quat
Generates the inverse of the specified quaternion.
Parameters
- Optionalsrc: Quat = ...
  The quaternion to invert. If not set, the operation is done in place.
Returns Quat
Self for chaining.
Example
```
// Create a quaternion rotated 180 degrees around the y-axis
const rot = new pc.Quat().setFromEulerAngles(0, 180, 0);

// Invert in place
rot.invert();
```
- Defined in src/core/math/quat.js:286

length

length(): number
Returns the magnitude of the specified quaternion.

Returns number
The magnitude of the specified quaternion.
Example
```
const q = new pc.Quat(0, 0, 0, 5);
const len = q.length();
// Outputs 5
console.log("The length of the quaternion is: " + len);
```
- Defined in src/core/math/quat.js:300

lengthSq

lengthSq(): number
Returns the magnitude squared of the specified quaternion.

Returns number
The magnitude squared of the quaternion.
Example
```
const q = new pc.Quat(3, 4, 0, 0);
const lenSq = q.lengthSq();
// Outputs 25
console.log("The length squared of the quaternion is: " + lenSq);
```
- Defined in src/core/math/quat.js:314

lerp

lerp(lhs: Quat, rhs: Quat, alpha: number): Quat
Performs a linear interpolation between two quaternions. The result of the interpolation is written to the quaternion calling the function.
Parameters
- lhs: Quat
  The quaternion to interpolate from.
- rhs: Quat
  The quaternion to interpolate to.
- alpha: number
  The value controlling the interpolation in relation to the two input quaternions. The value is in the range 0 to 1, 0 generating q1, 1 generating q2 and anything in between generating a linear interpolation between the two.
Returns Quat
Self for chaining.
Example
```
const q1 = new pc.Quat(-0.11, -0.15, -0.46, 0.87);
const q2 = new pc.Quat(-0.21, -0.21, -0.67, 0.68);

const result = new pc.Quat();
result.lerp(q1, q2, 0);   // Return q1
result.lerp(q1, q2, 0.5); // Return the midpoint interpolant
result.lerp(q1, q2, 1);   // Return q2
```
- Defined in src/core/math/quat.js:338

mul

mul(rhs: Quat): Quat

Returns the result of multiplying the specified quaternions together.

Parameters

rhs: Quat
The quaternion used as the second multiplicand of the operation.

Returns Quat

Self for chaining.

Example

const a = new pc.Quat().setFromEulerAngles(0, 30, 0);
const b = new pc.Quat().setFromEulerAngles(0, 60, 0);

// a becomes a 90 degree rotation around the Y axis
// In other words, a = a * b
a.mul(b);

console.log("The result of the multiplication is: " + a.toString());

mul2

mul2(lhs: Quat, rhs: Quat): Quat
Returns the result of multiplying the specified quaternions together.
Parameters
- lhs: Quat
  The quaternion used as the first multiplicand of the operation.
- rhs: Quat
  The quaternion used as the second multiplicand of the operation.
Returns Quat
Self for chaining.
Example
```
const a = new pc.Quat().setFromEulerAngles(0, 30, 0);
const b = new pc.Quat().setFromEulerAngles(0, 60, 0);
const r = new pc.Quat();

// r is set to a 90 degree rotation around the Y axis
// In other words, r = a * b
r.mul2(a, b);
```
- Defined in src/core/math/quat.js:415

mulScalar

mulScalar(scalar: number, src?: Quat): Quat
Multiplies each element of a quaternion by a number.
Parameters
- scalar: number
  The number to multiply by.
- Optionalsrc: Quat = ...
  The quaternion to scale. If not set, the operation is done in place.
Returns Quat
Self for chaining.
Example
```
const q = new pc.Quat(1, 2, 3, 4);
q.mulScalar(2);
// q is now [2, 4, 6, 8]
```
- Defined in src/core/math/quat.js:392

normalize

normalize(src?: Quat): Quat
Normalizes the specified quaternion.
Parameters
- Optionalsrc: Quat = ...
  The quaternion to normalize. If not set, the operation is done in place.
Returns Quat
The result of the normalization.
Example
```
const v = new pc.Quat(0, 0, 0, 5);
v.normalize();
// Outputs [0, 0, 0, 1]
console.log(v.toString());
```
- Defined in src/core/math/quat.js:445

set

set(x: number, y: number, z: number, w: number): Quat
Sets the specified quaternion to the supplied numerical values.
Parameters
- x: number
  The x component of the quaternion.
- y: number
  The y component of the quaternion.
- z: number
  The z component of the quaternion.
- w: number
  The w component of the quaternion.
Returns Quat
Self for chaining.
Example
```
const q = new pc.Quat();
q.set(1, 0, 0, 0);

// Outputs 1, 0, 0, 0
console.log("The result of the vector set is: " + q.toString());
```
- Defined in src/core/math/quat.js:476

setFromAxisAngle

setFromAxisAngle(axis: Vec3, angle: number): Quat
Sets a quaternion from an angular rotation around an axis.
Parameters
- axis: Vec3
  World space axis around which to rotate. Should be normalized.
- angle: number
  Angle to rotate around the given axis in degrees.
Returns Quat
Self for chaining.
Example
```
const q = new pc.Quat();
q.setFromAxisAngle(pc.Vec3.UP, 90);
```
- Defined in src/core/math/quat.js:495

setFromDirections

setFromDirections(from: Vec3, to: Vec3): Quat
Set the quaternion that represents the shortest rotation from one direction to another.
Parameters
- from: Vec3
  The direction to rotate from. It should be normalized.
- to: Vec3
  The direction to rotate to. It should be normalized.
Returns Quat
Self for chaining.
Example
```
const q = new pc.Quat();
const from = new pc.Vec3(0, 0, 1);
const to = new pc.Vec3(0, 1, 0);
q.setFromDirections(from, to);
```
- Defined in src/core/math/quat.js:648

setFromEulerAngles

setFromEulerAngles(ex: number | Vec3, ey?: number, ez?: number): Quat
Sets this quaternion to represent a rotation specified by Euler angles in degrees. The rotation is applied using an intrinsic XYZ order: first around the X-axis, then around the newly transformed Y-axis, and finally around the resulting Z-axis.
Parameters
- ex: number | Vec3
  The angle to rotate around the X-axis in degrees, or a Vec3 object containing the X, Y, and Z angles in degrees in its respective components (ex.x, ex.y, ex.z).
- Optionaley: number
  The angle to rotate around the Y-axis in degrees. This parameter is only used if ex is provided as a number.
- Optionalez: number
  The angle to rotate around the Z-axis in degrees. This parameter is only used if ex is provided as a number.
Returns Quat
The quaternion itself (this), now representing the orientation from the specified XYZ Euler angles. Allows for method chaining.
Example
```
// Create a quaternion from 3 individual Euler angles (interpreted as X, Y, Z order)
const q1 = new pc.Quat();
q1.setFromEulerAngles(45, 90, 180); // 45 deg around X, then 90 deg around Y', then 180 deg around Z''
console.log("From numbers:", q1.toString());
```
Example
```
// Create the same quaternion from a Vec3 containing the angles (X, Y, Z)
const anglesVec = new pc.Vec3(45, 90, 180);
const q2 = new pc.Quat();
q2.setFromEulerAngles(anglesVec);
console.log("From Vec3:", q2.toString()); // Should match q1
```
- Defined in src/core/math/quat.js:535

setFromMat4

setFromMat4(m: Mat4): Quat
Converts the specified 4x4 matrix to a quaternion. Note that since a quaternion is purely a representation for orientation, only the rotational part of the matrix is used.
Parameters
- m: Mat4
  The 4x4 matrix to convert.
Returns Quat
Self for chaining.
Example
```
// Create a 4x4 rotation matrix of 180 degrees around the y-axis
const rot = new pc.Mat4().setFromAxisAngle(pc.Vec3.UP, 180);

// Convert to a quaternion
const q = new pc.Quat().setFromMat4(rot);
```
- Defined in src/core/math/quat.js:576

slerp

slerp(lhs: Quat, rhs: Quat, alpha: number): Quat
Performs a spherical interpolation between two quaternions. The result of the interpolation is written to the quaternion calling the function.
Parameters
- lhs: Quat
  The quaternion to interpolate from.
- rhs: Quat
  The quaternion to interpolate to.
- alpha: number
  The value controlling the interpolation in relation to the two input quaternions. The value is in the range 0 to 1, 0 generating q1, 1 generating q2 and anything in between generating a spherical interpolation between the two.
Returns Quat
Self for chaining.
Example
```
const q1 = new pc.Quat(-0.11, -0.15, -0.46, 0.87);
const q2 = new pc.Quat(-0.21, -0.21, -0.67, 0.68);

const result = new pc.Quat();
result.slerp(q1, q2, 0);   // Return q1
result.slerp(q1, q2, 0.5); // Return the midpoint interpolant
result.slerp(q1, q2, 1);   // Return q2
```
- Defined in src/core/math/quat.js:695

toArray

toArray(arr?: number[], offset?: number): number[]
Parameters
- Optionalarr: number[]
  The array to populate with the quaternion's number components. If not specified, a new array is created.
- Optionaloffset: number
  The zero-based index at which to start copying elements to the array. Default is 0.
Returns number[]
The quaternion as an array.
- Defined in src/core/math/quat.js:820
toArray(arr: ArrayBufferView, offset?: number): ArrayBufferView
Parameters
- arr: ArrayBufferView
  The array to populate with the quaternion's number components. If not specified, a new array is created.
- Optionaloffset: number
  The zero-based index at which to start copying elements to the array. Default is 0.
Returns ArrayBufferView
The quaternion as an array.
- Defined in src/core/math/quat.js:828

toString

toString(): string
Converts the quaternion to string form.

Returns string
The quaternion in string form.
Example
```
const q = new pc.Quat(0, 0, 0, 1);
// Outputs [0, 0, 0, 1]
console.log(q.toString());
```
- Defined in src/core/math/quat.js:815

transformVector

transformVector(vec: Vec3, res?: Vec3): Vec3
Transforms a 3-dimensional vector by the specified quaternion.
Parameters
- vec: Vec3
  The 3-dimensional vector to be transformed.
- Optionalres: Vec3 = ...
  An optional 3-dimensional vector to receive the result of the transformation.
Returns Vec3
The transformed vector (res if specified, otherwise a new Vec3).
Example
```
// Create a 3-dimensional vector
const v = new pc.Vec3(1, 2, 3);

// Create a quaternion rotation
const q = new pc.Quat().setFromEulerAngles(10, 20, 30);

const tv = q.transformVector(v);
```
- Defined in src/core/math/quat.js:767

Class Quat

Index

Constructors

Properties

Methods

Constructors

constructor

Parameters

Returns Quat

Example

Parameters

Returns Quat

Example

Properties

w

x

y

z

Static ReadonlyIDENTITY

Static ReadonlyZERO

Methods

clone

Returns Quat

Example

copy

Parameters

Returns Quat

Example

dot

Parameters

Returns number

Example

equals

Parameters

Returns boolean

Example

equalsApprox

Parameters

Returns boolean

Example

fromArray

Parameters

Returns Quat

Example

getAxisAngle

Parameters

Returns number

Example

getEulerAngles

Parameters

Returns Vec3

Example

invert

Parameters

Returns Quat

Example

length

Returns number

Example

lengthSq

Returns number

Example

lerp

Parameters

Returns Quat

Example

mul

Parameters

Returns Quat

Example

mul2

Parameters

Returns Quat

Example

mulScalar

Parameters

Returns Quat

Example

normalize

Parameters

`Static` `Readonly`IDENTITY

`Static` `Readonly`ZERO