Quaternion

Quaternion — Aspose.3D FOSS for Java

Overview

Quaternion represents a unit quaternion used for rotation. It avoids gimbal lock and provides smooth interpolation between orientations. The Transform class stores rotation as a Quaternion accessible via getRotation() / setRotation().

Package: com.aspose.threed

import com.aspose.threed.*;

Constructor

Signature	Description
`Quaternion()`	Identity quaternion `(1, 0, 0, 0)`
`Quaternion(double w, double x, double y, double z)`	Constructs from four components

Public Fields

Quaternion uses public fields for component access (not getter/setter methods):

Field	Type	Access	Description
`w`	`double`	`q.w`	Scalar (real) part
`x`	`double`	`q.x`	X component of the vector part
`y`	`double`	`q.y`	Y component of the vector part
`z`	`double`	`q.z`	Z component of the vector part

Computed Properties

Name	Type	Getter	Description
`length`	`double`	`getLength()`	Magnitude of the quaternion (should be `1.0` for a unit quaternion)

Static Fields

Field	Type	Description
`IDENTITY`	`Quaternion`	The identity quaternion `(1, 0, 0, 0)` – no rotation

Static Methods

Method	Return Type	Description
`Quaternion.fromEuler(double x, double y, double z)`	`Quaternion`	Creates a quaternion from Euler angles in degrees
`Quaternion.fromAngleAxis(double angle, Vector3 axis)`	`Quaternion`	Creates a quaternion from an angle (radians) and rotation axis

Instance Methods

Method	Return Type	Description
`normalize()`	`Quaternion`	Returns a unit-length copy
`conjugate()`	`Quaternion`	Returns the conjugate (negated vector part)
`inverse()`	`Quaternion`	Returns the multiplicative inverse
`toEulerAngles()`	`Vector3`	Converts to Euler angles in degrees
`toMatrix()`	`Matrix4`	Converts to a 4x4 rotation matrix

Example

import com.aspose.threed.Scene;
import com.aspose.threed.Node;
import com.aspose.threed.*;

Scene scene = new Scene();
Node node = scene.getRootNode().createChildNode("rotated");

// Create from Euler angles (degrees)
Quaternion q = Quaternion.fromEuler(0.0, 90.0, 0.0);
node.getTransform().setRotation(q);

// Read back as Euler
Vector3 euler = node.getTransform().getEulerAngles();
System.out.println(euler);   // approximately (0, 90, 0)

// Create from angle-axis
Quaternion q2 = Quaternion.fromAngleAxis(Math.toRadians(45), Vector3.UNIT_Y);
node.getTransform().setRotation(q2);

// Combine rotations via multiply
Quaternion start = Quaternion.IDENTITY;
Quaternion end = Quaternion.fromEuler(0.0, 180.0, 0.0);
Quaternion combined = Quaternion.multiply(start, end);