Problem with Multisampled Renderbuffers use background-image in style about three.js

[Mugen87]

@TriggerBlazer Is the issue gone with this updated fiddle? https://jsfiddle.net/Lwsavq7e/

[TriggerBlazer]

That solves my problem. Thanks!

[WestLangley]

Is the issue gone with this updated fiddle?

That solves my problem.

@Mugen87 It is not obviously clear what "that" is without reformatting the two example files and doing a file-compare. Can you briefly state what you changed and why it worked? Perhaps doing so will also provide context for your last comment. Thanks.

[TriggerBlazer]

add
gl_FragColor.rgb *= gl_FragColor.a;
before ToneMapping in OutputShader

[Mugen87]

This is actually a duplicate of #26954.

#26954 discusses two issues. One is that MSAA can fail with HDR workflow (which is unrelated to this issue).

However the second one is related to premultiplied alpha which is not yet handled correctly in all use cases.

[Mugen87]

FYI: There is no fix in place yet since I'm not sure where and when to premultiply alpha in OutputShader. If the fix in the fiddle "looks" okay to you, use it. But it might be not 100% correct depending on how you configure your FX pipeline.