Change camera order ambiguity warning to warn_once!

[natepiano]

Objective

Fixes #22635

Camera order ambiguity warnings currently fire every frame, flooding the console.

Solution

• Change warn! to warn_once! in sort_cameras so the warning only fires once per ambiguity
• Remove the log filter workaround from ui_target_camera example since the warning is no longer spammy

Testing

Ran the ui_target_camera example and triggered a camera order ambiguity by clicking to give two cameras the same order. Verified the warning appears exactly once in the logs despite running for many frames afterward.

[IceSentry]

Would you be interested in doing the bevy_log dependency in a separate PR and also remove all the direct tracing usage we have in bevy_render? That's a weird quirk that we've had for a long time but nobody needed bevy_log directly until now.

[natepiano]

Would you be interested in doing the bevy_log dependency in a separate PR and also remove all the direct tracing usage we have in bevy_render? That's a weird quirk that we've had for a long time but nobody needed bevy_log directly until now.

Just so i'm clear - split this so that adding bevy_log dependency is completely by itself and then a separate PR to remove direct tracing? I don't mind doing it but just want to make sure I understand the request.

[IceSentry]

You can add bevy_log and remove direct tracing usage in the same PR because those things are directly related I think. I mostly just want this current PR to not have that noise.

[natepiano]

You can add bevy_log and remove direct tracing usage in the same PR because those things are directly related I think. I mostly just want this current PR to not have that noise.

I'm working on the PR for just replacing tracing with bevy_log but ran up against one issue -

bevy_render/src/renderer/mod.rs has a reference to tracing::event! here:

        #[cfg(feature = "tracing-tracy")]
        tracing::event!(
            bevy_log::Level::INFO,
            message = "finished frame",
            tracy.frame_mark = true
        );

tracing::event! is not re-exported from bevy_log - any concern if i add it to the list of re-exports from bevy_log?

pub use tracing::{
    self, debug, debug_span, error, error_span, event, info, info_span, trace, trace_span, warn,
    warn_span, Level,
};

it compiles and i think matches the intent of your ask

[natepiano]

just added #22652 PR with the replacement of tracing - once that merges i can rebase this PR on top of it

[IceSentry]

I would wait on the tracing PR to merge and then update the description of this PR but other than that LGTM

[github-actions]

You added a new example but didn't add metadata for it. Please update the root Cargo.toml file.