Add SkipDeferredLighting component

[JMS55]

Adds a new component for when you want to run the deferred gbuffer prepass, but not the lighting pass.

This will be used by bevy_solari in the future, as it'll do it's own shading pass, but still wants the gbuffer.

[DGriffin91]

This option exists specifically for this use case:

bevy/crates/bevy_pbr/src/lib.rs

Line 164 in 4da420c

pub add_default_deferred_lighting_plugin: bool,

Is it not sufficient?

[JMS55]

No because that's global, instead of per-view :/

[DGriffin91]

Ahh, gotcha. That make sense. Wonder if this option should be removed then in favor of the per view version?

[JMS55]

Lets leave it for now imo. I think there's still benefit in the global option.

[cart]

This makes sense in the short term.

I think its worth trying to think about how we could make this sort of thing a product of the configured pipeline / camera, rather than making it per-entity user-app-world configuration. It would be nice if we could spawn a normal gltf into a context that raytraces it, rather than needing to modify the gltf scene to fit the inner workings of the renderer's requirements. SkipDeferredLighting is an implementation detail that we could (and I will argue should) abstract away from the user app world.

Another path (if we decide "raytracing" is a scene property and not a camera/pipeline property) would be to scope this to being a material property (ex: materials that are configured to be "raytraceable" would have this property enabled). That way, it would be as simple as patching all of the materials in the scene to be "raytraced materials".

In the context of rendering, I like to think of the user's app world components as the "user facing contract" for an entity. SkipDeferredLighting doesn't feel like a user facing contract for entities. It feels like an implementation detail of a render pipeline.

[JMS55]

I changed the PR a little, now it's no longer inserted in the main world and extracted. I'll have bevy_solari insert it directly into the render world when extracting SolariLighting.

[cart]

I erroneously thought this was intended to be a per-entity component (sorry for skimming this ... that was irresponsible of me). I actually do not strongly object to using Components like this in the context of the Camera API + required components, as this sort of "view pipeline configuration" on Cameras is par for the course there.

This is still "implementation detail-ey" and theres still an argument to abstract this out from the user (ex: by doing this in the render world). But I care much less about that case. Feel free to do what you think is best there.