To capture a screenshot in JavaScript without using preserveDrawingBuffer: true, simply ensure that you take the screenshot immediately after rendering. As long as the screenshot is captured post-rendering but before exiting the current event, it will work reliably.
For instance, the following code snippet will consistently yield the desired result
renderer.render( scene, camera );
var screenshot = renderer.domElement.toDataURL();
In contrast, this approach may only produce random results due to its unpredictable timing
someElement.addEventListener('click', function() {
// This is not executed immediately after rendering, making it unreliable.
var screenshot = renderer.domElement.toDataURL();
});
In cases where users request screenshots in THREE.js examples, one can incorporate a render function for accurate captures like so
someElement.addEventListener('click', function() {
render();
var screenshot = renderer.domElement.toDataURL();
});
Alternatively, implement a solution such as the following:
var takeScreenshot;
function render() {
...
if (takeScreenshot) {
takeScreenshot = false;
var screenshot = renderer.domElement.toDataURL();
}
}
someElement.addEventListener('click', function() {
takeScreenshot = true;
});
By ensuring that the screenshot is taken promptly after rendering, various methods can be employed to guarantee consistent and accurate results.