The update() method of the CameraHelper class in Three.js updates the CameraHelper object with the transformation matrix of the camera. This method must be called every time the camera transforms or the viewport changes in order to ensure that the CameraHelper reflects the correct position and direction of the camera.
cameraHelper.update()
This method does not take any parameters.
The CameraHelper class provides a visual helper for debugging and understanding the position and direction of a camera in a Three.js scene. The CameraHelper object is created by passing a camera object to its constructor, and it will automatically adjust its size and shape to match the position and direction of the camera.
However, the CameraHelper object does not automatically update itself when the camera moves. Instead, the update() method must be called every time the camera transforms or the viewport changes in order to update the CameraHelper with the correct transformation matrix.
The update() method works by accessing the matrixWorld property of the camera object and using it to set the matrix and matrixWorld properties of the CameraHelper. This ensures that the CameraHelper reflects the correct position and direction of the camera.
// Create the camera object
var camera = new THREE.PerspectiveCamera( 75, window.innerWidth / window.innerHeight, 0.1, 1000 );
camera.position.set( 0, 0, 5 );
// Create the camera helper
var cameraHelper = new THREE.CameraHelper( camera );
scene.add( cameraHelper );
// Update the camera helper every animation frame
function animate() {
requestAnimationFrame( animate );
camera.position.y += 0.01;
camera.lookAt( 0, 0, 0 );
cameraHelper.update();
renderer.render( scene, camera );
}
animate();
In this example, we create a camera object and a CameraHelper, and add the CameraHelper to the scene. Then we call update() on the CameraHelper every animation frame to ensure that the CameraHelper reflects the correct position and direction of the camera as it moves.
The CameraHelper.update() method is an essential part of using the CameraHelper class in Three.js. It ensures that the CameraHelper object accurately reflects the position and direction of the camera in the scene, and must be called every time the camera transforms or the viewport changes.