Fix CameraProjection panic and improve CameraProjectionPlugin (#1…

…1808)

# Objective

Fix #11799 and improve
`CameraProjectionPlugin`

## Solution

`CameraProjectionPlugin` is now an all-in-one plugin for adding a custom
`CameraProjection`. I also added `PbrProjectionPlugin` which is like
`CameraProjectionPlugin` but for PBR.

P.S. I'd like to get this merged after
#11766.

---

## Changelog

- Changed `CameraProjectionPlugin` to be an all-in-one plugin for adding
a `CameraProjection`
- Removed `VisibilitySystems::{UpdateOrthographicFrusta,
UpdatePerspectiveFrusta, UpdateProjectionFrusta}`, now replaced with
`VisibilitySystems::UpdateFrusta`
- Added `PbrProjectionPlugin` for projection-specific PBR functionality.

## Migration Guide

`VisibilitySystems`'s `UpdateOrthographicFrusta`,
`UpdatePerspectiveFrusta`, and `UpdateProjectionFrusta` variants were
removed, they were replaced with `VisibilitySystems::UpdateFrusta`

crates/bevy_pbr/src/lib.rs

@@ -36,6 +36,8 @@ mod render;
 mod ssao;
 
 use bevy_color::{Color, LinearRgba};
+use std::marker::PhantomData;
+
 pub use bundle::*;
 pub use extended_material::*;
 pub use fog::*;
@@ -91,7 +93,10 @@ use bevy_core_pipeline::core_3d::graph::{Core3d, Node3d};
 use bevy_ecs::prelude::*;
 use bevy_render::{
     alpha::AlphaMode,
-    camera::{CameraUpdateSystem, Projection},
+    camera::{
+        CameraProjection, CameraUpdateSystem, OrthographicProjection, PerspectiveProjection,
+        Projection,
+    },
     extract_component::ExtractComponentPlugin,
     extract_resource::ExtractResourcePlugin,
     render_asset::prepare_assets,
@@ -303,6 +308,9 @@ impl Plugin for PbrPlugin {
                 ExtractComponentPlugin::<ShadowFilteringMethod>::default(),
                 LightmapPlugin,
                 LightProbePlugin,
+                PbrProjectionPlugin::<Projection>::default(),
+                PbrProjectionPlugin::<PerspectiveProjection>::default(),
+                PbrProjectionPlugin::<OrthographicProjection>::default(),
                 GpuMeshPreprocessPlugin {
                     use_gpu_instance_buffer_builder: self.use_gpu_instance_buffer_builder,
                 },
@@ -324,11 +332,7 @@ impl Plugin for PbrPlugin {
                         .after(TransformSystem::TransformPropagate)
                         .after(VisibilitySystems::CheckVisibility)
                         .after(CameraUpdateSystem),
-                    (
-                        clear_directional_light_cascades,
-                        build_directional_light_cascades::<Projection>,
-                    )
-                        .chain()
+                    clear_directional_light_cascades
                         .in_set(SimulationLightSystems::UpdateDirectionalLightCascades)
                         .after(TransformSystem::TransformPropagate)
                         .after(CameraUpdateSystem),
@@ -414,3 +418,21 @@ impl Plugin for PbrPlugin {
             .init_resource::<GlobalLightMeta>();
     }
 }
+
+/// [`CameraProjection`] specific PBR functionality.
+pub struct PbrProjectionPlugin<T: CameraProjection + Component>(PhantomData<T>);
+impl<T: CameraProjection + Component> Plugin for PbrProjectionPlugin<T> {
+    fn build(&self, app: &mut App) {
+        app.add_systems(
+            PostUpdate,
+            build_directional_light_cascades::<T>
+                .in_set(SimulationLightSystems::UpdateDirectionalLightCascades)
+                .after(clear_directional_light_cascades),
+        );
+    }
+}
+impl<T: CameraProjection + Component> Default for PbrProjectionPlugin<T> {
+    fn default() -> Self {
+        Self(Default::default())
+    }
+}

crates/bevy_render/src/camera/projection.rs

@@ -2,16 +2,20 @@ use std::marker::PhantomData;
 use std::ops::{Div, DivAssign, Mul, MulAssign};
 
 use crate::primitives::Frustum;
+use crate::view::VisibilitySystems;
 use bevy_app::{App, Plugin, PostStartup, PostUpdate};
 use bevy_ecs::prelude::*;
 use bevy_math::{AspectRatio, Mat4, Rect, Vec2, Vec3A};
 use bevy_reflect::{
     std_traits::ReflectDefault, GetTypeRegistration, Reflect, ReflectDeserialize, ReflectSerialize,
 };
 use bevy_transform::components::GlobalTransform;
+use bevy_transform::TransformSystem;
 use serde::{Deserialize, Serialize};
 
 /// Adds [`Camera`](crate::camera::Camera) driver systems for a given projection type.
+///
+/// If you are using `bevy_pbr`, then you need to add `PbrProjectionPlugin` along with this.
 pub struct CameraProjectionPlugin<T: CameraProjection + Component + GetTypeRegistration>(
     PhantomData<T>,
 );
@@ -29,12 +33,22 @@ impl<T: CameraProjection + Component + GetTypeRegistration> Plugin for CameraPro
             )
             .add_systems(
                 PostUpdate,
-                crate::camera::camera_system::<T>
-                    .in_set(CameraUpdateSystem)
-                    // We assume that each camera will only have one projection,
-                    // so we can ignore ambiguities with all other monomorphizations.
-                    // FIXME: Add an archetype invariant for this https://github.com/bevyengine/bevy/issues/1481.
-                    .ambiguous_with(CameraUpdateSystem),
+                (
+                    crate::camera::camera_system::<T>
+                        .in_set(CameraUpdateSystem)
+                        // We assume that each camera will only have one projection,
+                        // so we can ignore ambiguities with all other monomorphizations.
+                        // FIXME: Add an archetype invariant for this https://github.com/bevyengine/bevy/issues/1481.
+                        .ambiguous_with(CameraUpdateSystem),
+                    crate::view::update_frusta::<T>
+                        .in_set(VisibilitySystems::UpdateFrusta)
+                        .after(crate::camera::camera_system::<T>)
+                        .after(TransformSystem::TransformPropagate)
+                        // We assume that no camera will have more than one projection component,
+                        // so these systems will run independently of one another.
+                        // FIXME: Add an archetype invariant for this https://github.com/bevyengine/bevy/issues/1481.
+                        .ambiguous_with(VisibilitySystems::UpdateFrusta),
+                ),
             );
     }
 }

crates/bevy_render/src/view/visibility/mod.rs

@@ -15,10 +15,7 @@ use bevy_transform::{components::GlobalTransform, TransformSystem};
 use bevy_utils::{Parallel, TypeIdMap};
 
 use crate::{
-    camera::{
-        camera_system, Camera, CameraProjection, OrthographicProjection, PerspectiveProjection,
-        Projection,
-    },
+    camera::{Camera, CameraProjection},
     mesh::Mesh,
     primitives::{Aabb, Frustum, Sphere},
 };
@@ -239,12 +236,8 @@ pub enum VisibilitySystems {
     /// Label for the [`calculate_bounds`], `calculate_bounds_2d` and `calculate_bounds_text2d` systems,
     /// calculating and inserting an [`Aabb`] to relevant entities.
     CalculateBounds,
-    /// Label for the [`update_frusta<OrthographicProjection>`] system.
-    UpdateOrthographicFrusta,
-    /// Label for the [`update_frusta<PerspectiveProjection>`] system.
-    UpdatePerspectiveFrusta,
-    /// Label for the [`update_frusta<Projection>`] system.
-    UpdateProjectionFrusta,
+    /// Label for [`update_frusta`] in [`CameraProjectionPlugin`](crate::camera::CameraProjectionPlugin).
+    UpdateFrusta,
     /// Label for the system propagating the [`InheritedVisibility`] in a
     /// [`hierarchy`](bevy_hierarchy).
     VisibilityPropagate,
@@ -261,38 +254,14 @@ impl Plugin for VisibilityPlugin {
 
         app.configure_sets(
             PostUpdate,
-            (
-                CalculateBounds,
-                UpdateOrthographicFrusta,
-                UpdatePerspectiveFrusta,
-                UpdateProjectionFrusta,
-                VisibilityPropagate,
-            )
+            (CalculateBounds, UpdateFrusta, VisibilityPropagate)
                 .before(CheckVisibility)
                 .after(TransformSystem::TransformPropagate),
         )
         .add_systems(
             PostUpdate,
             (
                 calculate_bounds.in_set(CalculateBounds),
-                update_frusta::<OrthographicProjection>
-                    .in_set(UpdateOrthographicFrusta)
-                    .after(camera_system::<OrthographicProjection>)
-                    // We assume that no camera will have more than one projection component,
-                    // so these systems will run independently of one another.
-                    // FIXME: Add an archetype invariant for this https://github.com/bevyengine/bevy/issues/1481.
-                    .ambiguous_with(update_frusta::<PerspectiveProjection>)
-                    .ambiguous_with(update_frusta::<Projection>),
-                update_frusta::<PerspectiveProjection>
-                    .in_set(UpdatePerspectiveFrusta)
-                    .after(camera_system::<PerspectiveProjection>)
-                    // We assume that no camera will have more than one projection component,
-                    // so these systems will run independently of one another.
-                    // FIXME: Add an archetype invariant for this https://github.com/bevyengine/bevy/issues/1481.
-                    .ambiguous_with(update_frusta::<Projection>),
-                update_frusta::<Projection>
-                    .in_set(UpdateProjectionFrusta)
-                    .after(camera_system::<Projection>),
                 (visibility_propagate_system, reset_view_visibility).in_set(VisibilityPropagate),
                 check_visibility::<WithMesh>.in_set(CheckVisibility),
             ),
@@ -320,9 +289,7 @@ pub fn calculate_bounds(
 
 /// Updates [`Frustum`].
 ///
-/// This system is used in system sets [`VisibilitySystems::UpdateProjectionFrusta`],
-/// [`VisibilitySystems::UpdatePerspectiveFrusta`], and
-/// [`VisibilitySystems::UpdateOrthographicFrusta`].
+/// This system is used in [`CameraProjectionPlugin`](crate::camera::CameraProjectionPlugin).
 pub fn update_frusta<T: Component + CameraProjection + Send + Sync + 'static>(
     mut views: Query<
         (&GlobalTransform, &T, &mut Frustum),