function removeStages(collection) {
  if (!collection._stagesRemoved) {
    return;
  }

  collection._stagesRemoved = false;

  const newStages = [];
  const stages = collection._stages;
  for (let i = 0, j = 0; i < stages.length; ++i) {
    const stage = stages[i];
    if (stage) {
      stage._index = j++;
      newStages.push(stage);
    }
  }

  collection._stages = newStages;
}
Control the exposure when HDR is on. Less than 1.0 makes the tonemapping darker while greater than 1.0 makes it brighter.

@example viewer.scene.postProcessStages.exposure = 1.0;

@default 1.0
@memberof PostProcessStageCollection.prototype
@type {number}