Quaternion

Quaternion — Aspose.3D FOSS for Python API Reference

Overview

Quaternion represents a unit quaternion used to encode 3D rotations. Unlike Euler angles, quaternions avoid gimbal lock and interpolate smoothly. The Transform.rotation property on a scene node stores a Quaternion.

The components are stored as (w, x, y, z) where w is the scalar part and (x, y, z) form the vector part.

from aspose.threed.utilities import Quaternion
import math

# Identity quaternion (no rotation)
q = Quaternion()   # w=1, x=0, y=0, z=0

# Rotation of 90 degrees around the Y axis
q = Quaternion.from_euler_angle(0.0, math.radians(90), 0.0)

Package: aspose.threed.utilities

from aspose.threed.utilities import Quaternion

Constructor

Signature	Description
`Quaternion()`	Identity quaternion `(w=1, x=0, y=0, z=0)`
`Quaternion(w, x, y, z)`	Explicit component constructor

Properties

Name	Type	Description
`w`	`float`	Scalar (real) part
`x`	`float`	Vector x-component
`y`	`float`	Vector y-component
`z`	`float`	Vector z-component
`length`	`float`	Magnitude of the quaternion

Static Factory Methods

Method	Return Type	Description
`Quaternion.from_euler_angle(pitch, yaw, roll)`	`Quaternion`	Constructs from Euler angles in radians (pitch=X, yaw=Y, roll=Z). Also accepts a `Vector3` as the first argument
`Quaternion.from_angle_axis(angle, axis)`	`Quaternion`	Constructs from an angle (radians) and a `Vector3` axis
`Quaternion.from_rotation(orig, dest)`	`Quaternion`	Shortest-arc rotation from direction `orig` to direction `dest`
`Quaternion.interpolate(t, from_q, to_q)`	`Quaternion`	SLERP interpolation; `t` in `[0, 1]`
`Quaternion.slerp(t, v1, v2)`	`Quaternion`	Alias for `interpolate`

Instance Methods

Method	Return Type	Description
`normalize()`	`Quaternion`	Returns a unit-length copy
`conjugate()`	`Quaternion`	Returns the conjugate `(w, -x, -y, -z)`
`inverse()`	`Quaternion`	Returns the multiplicative inverse; raises `ValueError` if length is zero
`dot(q)`	`float`	Dot product with another quaternion
`concat(rhs)`	`Quaternion`	Hamilton product (composition of two rotations)
`euler_angles()`	`Vector3`	Extracts Euler angles (radians) as `Vector3(roll, pitch, yaw)`
`to_matrix(translation=None)`	`Matrix4`	Converts to a 4×4 rotation matrix; optionally embeds a translation `Vector3`
`to_angle_axis(angle, axis)`	`None`	Decomposes into angle (radians) and axis; results written to single-element lists `angle[0]` and `axis[0]`

Example

from aspose.threed import Scene
from aspose.threed.utilities import Quaternion, Vector3
import math

scene = Scene()
node = scene.root_node.create_child_node("rotated_box")

# Rotate 45 degrees around the Y axis
angle = math.radians(45)
q = Quaternion.from_euler_angle(0.0, angle, 0.0)
node.transform.rotation = q

# SLERP between two rotations
q_start = Quaternion.from_euler_angle(0, 0, 0)
q_end   = Quaternion.from_euler_angle(0, math.pi, 0)
q_mid   = Quaternion.slerp(0.5, q_start, q_end)

# Convert to matrix (useful for manual transforms)
mat = q.to_matrix()

# Extract Euler angles back
angles = q.euler_angles()   # Vector3(roll, pitch, yaw)
print(math.degrees(angles.y))   # ~45.0