Add Camera::render_on_top

Author: HackerFoo

crates/bevy_core_pipeline/src/lib.rs

@@ -398,6 +398,7 @@ pub fn prepare_core_views_system(
 ) {
     let mut textures = HashMap::default();
     for (entity, view, camera) in views_3d.iter() {
+        let mut render_on_top = false;
         let mut get_cached_texture = || {
             texture_cache.get(
                 &render_device,
@@ -418,6 +419,7 @@ pub fn prepare_core_views_system(
             )
         };
         let cached_texture = if let Some(camera) = camera {
+            render_on_top = camera.render_on_top;
             textures
                 .entry(camera.target.clone())
                 .or_insert_with(get_cached_texture)
@@ -428,6 +430,7 @@ pub fn prepare_core_views_system(
         commands.entity(entity).insert(ViewDepthTexture {
             texture: cached_texture.texture,
             view: cached_texture.default_view,
+            render_on_top,
         });
     }
 }

crates/bevy_core_pipeline/src/main_pass_3d.rs

@@ -68,7 +68,11 @@ impl Node for MainPass3dNode {
                     view: &depth.view,
                     // NOTE: The opaque main pass loads the depth buffer and possibly overwrites it
                     depth_ops: Some(Operations {
-                        load: LoadOp::Load,
+                        load: if depth.render_on_top {
+                            LoadOp::Clear(0.0)
+                        } else {
+                            LoadOp::Load
+                        },
                         store: true,
                     }),
                     stencil_ops: None,

crates/bevy_render/src/camera/camera.rs

@@ -27,6 +27,7 @@ pub struct Camera {
     pub name: Option<String>,
     #[reflect(ignore)]
     pub target: RenderTarget,
+    pub render_on_top: bool,
     #[reflect(ignore)]
     pub depth_calculation: DepthCalculation,
     pub near: f32,

crates/bevy_render/src/camera/mod.rs

@@ -74,6 +74,7 @@ pub struct ExtractedCamera {
     pub target: RenderTarget,
     pub name: Option<String>,
     pub physical_size: Option<UVec2>,
+    pub render_on_top: bool,
 }
 
 fn extract_cameras(
@@ -96,6 +97,7 @@ fn extract_cameras(
                         target: camera.target.clone(),
                         name: camera.name.clone(),
                         physical_size: camera.target.get_physical_size(&windows, &images),
+                        render_on_top: camera.render_on_top,
                     },
                     ExtractedView {
                         projection: camera.projection_matrix,

crates/bevy_render/src/view/mod.rs

@@ -137,6 +137,7 @@ impl ViewTarget {
 pub struct ViewDepthTexture {
     pub texture: Texture,
     pub view: TextureView,
+    pub render_on_top: bool,
 }
 
 fn prepare_view_uniforms(