How do I stop requestAnimationFrame

When using Three.js for animation rendering, you typically use requestAnimationFrame to continuously update the rendering. If you need to stop the animation in certain scenarios, you can achieve this by canceling requestAnimationFrame.

First, each time you call requestAnimationFrame, it returns a unique ID. You can use this ID to stop the animation by calling cancelAnimationFrame.

1. Save the requestAnimationFrame ID: When you call requestAnimationFrame, store the returned ID in a variable. This allows you to use the ID to stop the animation when needed.

2. Call cancelAnimationFrame to stop the animation: When you want to stop the animation, call cancelAnimationFrame using the previously stored ID. This will halt further animation frame calls.

Example Code:

javascript
let frameId;  // Store the `requestAnimationFrame` ID

function animate() {
    frameId = requestAnimationFrame(animate);
    // Your rendering code here
    render();
}

function stopAnimation() {
    cancelAnimationFrame(frameId);
}

function render() {
    // Your rendering logic, such as updating object positions and camera views
    renderer.render(scene, camera);
}

// Start the animation
animate();

// Assume we listen for keyboard events to stop the animation
window.addEventListener('keydown', (event) => {
    if (event.key === 's') {  // When the user presses the 's' key
        stopAnimation();
    }
});

In this example, we first define an animate function that calls itself repeatedly to create an animation loop. The animate function calls requestAnimationFrame each time it executes and stores the returned ID in the frameId variable. When the user presses the 's' key, the stopAnimation function is called, using cancelAnimationFrame and the previously stored frameId to halt further animation frame calls.

This method effectively controls the start and stop of the animation, suitable for scenarios requiring dynamic control of Three.js animation rendering.