Examples: Revert to manual PMREMGenerator usage.

[Mugen87]

Related issue: Fixed #22197.

Description

If an app wants to debug a cubeUV map, it's better when PMREMGenerator is used in app level code. The internal implementation is not flexible enough and I would not enhance it just for the purpose of visualizing the preprocessed env map.

[WestLangley]

If an app wants to debug a cubeUV map, it's better when PMREMGenerator is used in app level code.

No it is not.

The internal implementation is not flexible enough and I would not enhance it just for the purpose of visualizing the preprocessed env map.

What???. This is fixable. The point is to remove PMREM from the app level.

[Mugen87]

Visualizing the env map like in the example is no valid use case to me. The code assigns it to the map property which is obviously not the intended way of using the env map produced by PMREMGenerator. It's a hack for debugging and I would not build an API around that. Using PMREMGenerator on app level for this particular use case is fine.

[mrdoob]

I agree with @Mugen87. And I think this is a good reason for not removing PMREMGenerator from the public API.

[mrdoob]

Thanks!