Reflector/Refractor/Water warn when renderer.outputEncoding is not Linear

[mrdoob]

While cleaning up webgl_shaders_ocean I bumped into the issue that programs were getting recompiled twice every frame when setting renderer.outputEncoding to sRGBEncoding.

The fact that Water uses LinearEncoding forces materials to be recompiled when rendering the reflection view. This applies to Reflector and Refractor too.

I think the right fix is to support multiple compiled programs per material (something I'm currently investigating). Until that's done I think it'll be better to warn the user.

[mrdoob]

Maybe Reflector and Refractor doesn't need this and we could just do renderTarget.texture.encoding = renderer.outputEncoding; before rendering, but I think we would be encoding twice? 🤔

[Mugen87]

I think the right fix is to support multiple compiled programs per material (something I'm currently investigating).

Another possibility to fix this particular issue is to provide the output encoding as a uniform. That would also avoid a recompile and is probably easier to implement. Multiple programs will also trigger program binds and thus WebGL state changes which is not the case when a uniform value is changed.

TBH, I'm not sure the warning is much of a help since the encoding parameter was a workaround that made the mirror and other objects usable with sRGB output encoding. This is now not the case anymore. I guess I would prefer to rollback the change if there is no other solution in the r118 dev cycle.

[mrdoob]

Another possibility to fix this particular issue is to provide the output encoding as a uniform. That would also avoid a recompile and is probably easier to implement. Multiple programs will also trigger program binds and thus WebGL state changes which is not the case when a uniform value is changed.

We would also need a uniform for toneMapping then. Reflector and Refractor doesn't need it but Water does lighting and texture compositing in its shader.

[mrdoob]

TBH, I'm not sure the warning is much of a help since the encoding parameter was a workaround that made the mirror and other objects usable with sRGB output encoding. This is now not the case anymore. I guess I would prefer to rollback the change if there is no other solution in the r118 dev cycle.

Happy to revert if this doesn't get solved in time.