ToneMappingEffect affects the background color

[MajorMeerkatThe3rd]

Currently the ToneMappingEffect affects the background color, this can be reproduced on the demo page.

It would be very helpful to have a setting to ignore the background, like for other passes.

[vanruesc]

Hi,

I agree that it would be a useful feature to have, but there are currently no plans to add support for masking to ToneMappingEffect. The reason being transparent objects.

Implementing masking based on min/max depth wouldn't be too difficult. However, transparent objects don't write depth so all transparent fragments rendered on top of the background would no longer be tone mapped. Depth-based masking also causes aliasing artifacts around object edges and it requires additional texture sampling which isn't free.

I haven't tried this, but it might be possible to modify three's skybox shader to output untonemapped/inverse-tonemapped colors (http://www.codersnotes.com/notes/untonemapping/). After applying tone mapping, the final output should then look closer to the original colors.

[MajorMeerkatThe3rd]

Hello @vanruesc,

thank you for this very insightful answer! This makes the complexity of the issue much more clear to me.
Once I find some time, I'll try the suggested approach and will report back!

Thank you!