Bloom washes the whole scene out to white

• Setting postProcessStages.bloom.enabled to true makes the whole screen look fogged and blurs all building edges.
• Frame rate drops by roughly a third.
• Disabling bloom restores the image immediately.

1. Toggle only enabled and leave the other uniforms untouched for a clean A/B comparison.
2. Print bloom.uniforms.brightness and bloom.uniforms.delta, whose defaults are 0.8 and 1.
3. Set brightness to 0 and see whether the image is still washed out, to rule out other stages.
4. Check the order of stages added through postProcessStages.add.

Set bloom.uniforms.brightness to 0.15 and delta to 0.9 so only the top 10% of luminance blooms, with sigma 3.0 and contrast 128.0. Add a tonemapping stage from PostProcessStageLibrary with scene.highDynamicRange true to bring highlights back into range.

var bloom = viewer.scene.postProcessStages.bloom;
console.log(bloom.enabled, bloom.uniforms.brightness, bloom.uniforms.delta);
// true 0.8 1

var bloom = viewer.scene.postProcessStages.bloom;
bloom.enabled = true;
bloom.uniforms.brightness = 0.15;
bloom.uniforms.delta = 0.9;        // 只有亮度前 10% 参与
bloom.uniforms.sigma = 3.0;
bloom.uniforms.stepSize = 1.0;
bloom.uniforms.contrast = 128.0;

• Running bloom before tonemapping, which clips highlights to white; running it after compresses the glow away.
• Rebuilding the post-process chain every frame to toggle night mode instead of flipping enabled and calling requestRender.