Ensure depth texture is shared between passes

Author: HackerFoo

crates/bevy_core_pipeline/src/lib.rs

@@ -23,7 +23,7 @@ use bevy_app::{App, Plugin};
 use bevy_core::FloatOrd;
 use bevy_ecs::prelude::*;
 use bevy_render::{
-    camera::{ActiveCameras, CameraPlugin, RenderTarget},
+    camera::{ActiveCameras, CameraPlugin, ExtractedCamera, RenderTarget},
     color::Color,
     render_graph::{EmptyNode, RenderGraph, SlotInfo, SlotType},
     render_phase::{
@@ -393,32 +393,43 @@ pub fn prepare_core_views_system(
     msaa: Res<Msaa>,
     render_device: Res<RenderDevice>,
     views_3d: Query<
-        (Entity, &ExtractedView),
+        (Entity, &ExtractedView, Option<&ExtractedCamera>),
         (
             With<RenderPhase<Opaque3d>>,
             With<RenderPhase<AlphaMask3d>>,
             With<RenderPhase<Transparent3d>>,
         ),
     >,
 ) {
-    for (entity, view) in views_3d.iter() {
-        let cached_texture = texture_cache.get(
-            &render_device,
-            TextureDescriptor {
-                label: Some("view_depth_texture"),
-                size: Extent3d {
-                    depth_or_array_layers: 1,
-                    width: view.width as u32,
-                    height: view.height as u32,
+    let mut textures = HashMap::default();
+    for (entity, view, camera) in views_3d.iter() {
+        let mut get_cached_texture = || {
+            texture_cache.get(
+                &render_device,
+                TextureDescriptor {
+                    label: Some("view_depth_texture"),
+                    size: Extent3d {
+                        depth_or_array_layers: 1,
+                        width: view.width as u32,
+                        height: view.height as u32,
+                    },
+                    mip_level_count: 1,
+                    sample_count: msaa.samples,
+                    dimension: TextureDimension::D2,
+                    format: TextureFormat::Depth32Float, /* PERF: vulkan docs recommend using 24
+                                                          * bit depth for better performance */
+                    usage: TextureUsages::RENDER_ATTACHMENT,
                 },
-                mip_level_count: 1,
-                sample_count: msaa.samples,
-                dimension: TextureDimension::D2,
-                format: TextureFormat::Depth32Float, /* PERF: vulkan docs recommend using 24
-                                                      * bit depth for better performance */
-                usage: TextureUsages::RENDER_ATTACHMENT,
-            },
-        );
+            )
+        };
+        let cached_texture = if let Some(camera) = camera {
+            textures
+                .entry(camera.target.clone())
+                .or_insert_with(get_cached_texture)
+                .clone()
+        } else {
+            get_cached_texture()
+        };
         commands.entity(entity).insert(ViewDepthTexture {
             texture: cached_texture.texture,
             view: cached_texture.default_view,

crates/bevy_core_pipeline/src/main_pass_3d.rs

@@ -139,7 +139,7 @@ impl Node for MainPass3dNode {
                     // transparent ones.
                     depth_ops: Some(Operations {
                         load: LoadOp::Load,
-                        store: false,
+                        store: true,
                     }),
                     stencil_ops: None,
                 }),

crates/bevy_render/src/texture/texture_cache.rs

@@ -18,6 +18,7 @@ struct CachedTextureMeta {
 /// A cached GPU [`Texture`] with corresponding [`TextureView`].
 /// This is useful for textures that are created repeatedly (each frame) in the rendering process
 /// to reduce the amount of GPU memory allocations.
+#[derive(Clone)]
 pub struct CachedTexture {
     pub texture: Texture,
     pub default_view: TextureView,

examples/3d/two_passes.rs

@@ -104,7 +104,7 @@ fn setup(
         ..Default::default()
     });
 
-    let split = 1.0;
+    let split = 2.0;
 
     // This specifies the layer used for the first pass, which will be attached to the first pass camera and cube.
     let first_pass_layer = RenderLayers::layer(1);
@@ -158,7 +158,7 @@ fn setup(
             mesh: cube_handle,
             material: material_handle,
             transform: Transform {
-                translation: Vec3::new(split, 0.0, 1.5),
+                translation: Vec3::new(split, 0.0, -4.5),
                 rotation: Quat::from_rotation_x(-std::f32::consts::PI / 5.0),
                 ..Default::default()
             },