Examples: Improve the slider in the wide gamut example

[WestLangley]

Improved the look of the slider.

Also fixed bugs in the slider when resizing the window.

[WestLangley]

The updated screenshot is not correct...

[Mugen87]

The E2E testing for this particular example should be improved by updating https://github.com/mrdoob/three.js/blob/dev/test/e2e/clean-page.js. This script ensure to remove all HTML which overlays the renderer's canvas so the testing can focus on the renderer output.

[Mugen87]

It seems adding the slider and label class to the following line should be sufficient.

three.js/test/e2e/clean-page.js

Line 12 in 2b5e500

style.innerHTML = '#info, button, input, body > div.lil-gui, body > div.lbl { display: none !important; }';

[Mugen87]

The above is the screenshot generated on my system so it's not a general issue.

Did you do a npm i before making the screenshot? Maybe you are using an outdated dependencies.

[WestLangley]

I tried updating, but no luck... (I am on a mac, using homebrew.)

It appears the animation loop is rendering before the textures load.

[Mugen87]

Then let me update the screenshot after the merge so it's not blocking the PR.

[WestLangley]

OK. I reverted the screenshot update.

[Mugen87]

6b23527