Chapter 344: EllipseCurve

Core Idea

A curve representing an ellipse.

Key Concepts

aClockwise : boolean: Whether the ellipse is drawn clockwise or not.
aEndAngle : number: The end angle of the curve in radians starting from the positive X axis.
aRotation : number: The rotation angle of the ellipse in radians, counterclockwise from the positive X axis.
aStartAngle : number: The start angle of the curve in radians starting from the positive X axis.
aX : number: The X center of the ellipse.
aY : number: The Y center of the ellipse.
isEllipseCurve : boolean (readonly): This flag can be used for type testing.
xRadius : number: The radius of the ellipse in the x direction. Setting the this value equal to the EllipseCurve#yRadius will re…
yRadius : number: The radius of the ellipse in the y direction. Setting the this value equal to the EllipseCurve#xRadius will re…

Code Examples

const curve = new THREE.EllipseCurve(
	0, 0,
	10, 10,
	0, 2 * Math.PI,
	false,
	0
);
const points = curve.getPoints( 50 );
const geometry = new THREE.BufferGeometry().setFromPoints( points );
const material = new THREE.LineBasicMaterial( { color: 0xff0000 } );
// Create the final object to add to the scene
const ellipse = new THREE.Line( geometry, material );

What it demonstrates: Typical usage of EllipseCurve.

Reference Tables

Constructor

Signature
`new EllipseCurve( aX : number, aY : number, xRadius : number, yRadius : number, aStartAngle : number, aEndAngle : number, aClockwise : boolean, aRotation : number )`

Properties

Property	Description
`.aClockwise : boolean`	Whether the ellipse is drawn clockwise or not.
`.aEndAngle : number`	The end angle of the curve in radians starting from the positive X axis.
`.aRotation : number`	The rotation angle of the ellipse in radians, counterclockwise from the positive X axis.
`.aStartAngle : number`	The start angle of the curve in radians starting from the positive X axis.
`.aX : number`	The X center of the ellipse.
`.aY : number`	The Y center of the ellipse.
`.isEllipseCurve : boolean (readonly)`	This flag can be used for type testing.
`.xRadius : number`	The radius of the ellipse in the x direction. Setting the this value equal to the EllipseCurve#yRadius will result in a circle.
`.yRadius : number`	The radius of the ellipse in the y direction. Setting the this value equal to the EllipseCurve#xRadius will result in a circle.

Methods

Method	Description
`.getPoint( t : number, optionalTarget : Vector2 ) : Vector2`	Returns a point on the curve.

Key Takeaways

EllipseCurve extends: Curve
Most relevant properties: aClockwise, aEndAngle, aRotation, aStartAngle.
Key methods: getPoint.

Connects To

Curve: parent class
Source: src/extras/curves/EllipseCurve.js