Making sprite size fixed while zoom

I am new to even JS. I am trying to show a model with a sprite(with texture) beside it. I need the sprite size to be fixed even while i zoom. it is working with “mousedown” event listener but not with “wheel” or “scroll”. I am using orbitcontrol.js too.

document.addEventListener(‘wheel’, scaler);
function scaler() {
scale = sprite2.position.distanceTo(camera.position) / virtual_d;
sprite2.scale.set(scale, scale, scale);

Like so: