examples: Fix view z calculation for sort key

Author: superdump

crates/bevy_pbr/src/light.rs

@@ -799,6 +799,9 @@ pub(crate) fn assign_lights_to_clusters(
                 lights
                     .iter()
                     .map(|light| {
+                        // NOTE: row 2 of the inverse view matrix dotted with the world space
+                        // translation gives the z component of translation of the mesh in view
+                        // space
                         -inverse_view_row_2.dot(light.translation.extend(1.0)) + light.range
                     })
                     .reduce(f32::max)

crates/bevy_pbr/src/wireframe.rs

@@ -147,6 +147,8 @@ fn queue_wireframes(
                         entity,
                         pipeline: pipeline_id,
                         draw_function: draw_custom,
+                        // NOTE: row 2 of the inverse view matrix dotted with column 3 of the model matrix
+                        // gives the z component of translation of the mesh in view space
                         distance: inverse_view_row_2.dot(mesh_uniform.transform.col(3)),
                     });
                 }

examples/shader/animate_shader.rs

@@ -112,7 +112,7 @@ fn queue_custom(
         | MeshPipelineKey::from_primitive_topology(PrimitiveTopology::TriangleList);
 
     for (view, mut transparent_phase) in views.iter_mut() {
-        let view_row_2 = view.view.row(2);
+        let inverse_view_row_2 = view.view.inverse().row(2);
         for (entity, mesh_uniform, mesh_handle) in material_meshes.iter() {
             if let Some(mesh) = render_meshes.get(mesh_handle) {
                 let pipeline = pipelines
@@ -122,7 +122,9 @@ fn queue_custom(
                     entity,
                     pipeline,
                     draw_function: draw_custom,
-                    distance: view_row_2.dot(mesh_uniform.transform.col(3)),
+                    // NOTE: row 2 of the inverse view matrix dotted with column 3 of the model matrix
+                    // gives the z component of translation of the mesh in view space
+                    distance: inverse_view_row_2.dot(mesh_uniform.transform.col(3)),
                 });
             }
         }

examples/shader/shader_defs.rs

@@ -149,7 +149,7 @@ fn queue_custom(
         .unwrap();
     let msaa_key = MeshPipelineKey::from_msaa_samples(msaa.samples);
     for (view, mut transparent_phase) in views.iter_mut() {
-        let view_row_2 = view.view.row(2);
+        let inverse_view_row_2 = view.view.inverse().row(2);
         for (entity, mesh_handle, mesh_uniform, is_red) in material_meshes.iter() {
             if let Some(mesh) = render_meshes.get(mesh_handle) {
                 let key =
@@ -166,7 +166,9 @@ fn queue_custom(
                     entity,
                     pipeline,
                     draw_function: draw_custom,
-                    distance: view_row_2.dot(mesh_uniform.transform.col(3)),
+                    // NOTE: row 2 of the inverse view matrix dotted with column 3 of the model matrix
+                    // gives the z component of translation of the mesh in view space
+                    distance: inverse_view_row_2.dot(mesh_uniform.transform.col(3)),
                 });
             }
         }

examples/shader/shader_instancing.rs

@@ -117,7 +117,7 @@ fn queue_custom(
     let msaa_key = MeshPipelineKey::from_msaa_samples(msaa.samples);
 
     for (view, mut transparent_phase) in views.iter_mut() {
-        let view_row_2 = view.view.row(2);
+        let inverse_view_row_2 = view.view.inverse().row(2);
         for (entity, mesh_uniform, mesh_handle) in material_meshes.iter() {
             if let Some(mesh) = meshes.get(mesh_handle) {
                 let key =
@@ -129,7 +129,9 @@ fn queue_custom(
                     entity,
                     pipeline,
                     draw_function: draw_custom,
-                    distance: view_row_2.dot(mesh_uniform.transform.col(3)),
+                    // NOTE: row 2 of the inverse view matrix dotted with column 3 of the model matrix
+                    // gives the z component of translation of the mesh in view space
+                    distance: inverse_view_row_2.dot(mesh_uniform.transform.col(3)),
                 });
             }
         }