Add test for GltfLoaderSettings::override_sampler and mipmap rendering

Cargo.toml

@@ -1410,6 +1410,14 @@ doc-scrape-examples = true
 [package.metadata.example.no_prepass]
 hidden = true
 
+[[example]]
+name = "gltf_override_sampler"
+path = "tests/gltf/gltf_override_sampler.rs"
+doc-scrape-examples = true
+
+[package.metadata.example.gltf_override_sampler]
+hidden = true
+
 # Animation
 [[example]]
 name = "animation_events"

assets/models/checkerboard/checkerboard.gltf

@@ -0,0 +1,143 @@
+{
+	"asset":{
+		"generator":"Khronos glTF Blender I/O v4.3.47",
+		"version":"2.0"
+	},
+	"extensionsUsed":[
+		"KHR_materials_unlit"
+	],
+	"scene":0,
+	"scenes":[
+		{
+			"name":"Scene",
+			"nodes":[
+				0
+			]
+		}
+	],
+	"nodes":[
+		{
+			"mesh":0,
+			"name":"Plane"
+		}
+	],
+	"materials":[
+		{
+			"doubleSided":true,
+			"extensions":{
+				"KHR_materials_unlit":{}
+			},
+			"name":"Material.001",
+			"pbrMetallicRoughness":{
+				"baseColorTexture":{
+					"index":0
+				},
+				"metallicFactor":0,
+				"roughnessFactor":0.9
+			}
+		}
+	],
+	"meshes":[
+		{
+			"name":"Plane",
+			"primitives":[
+				{
+					"attributes":{
+						"POSITION":0,
+						"NORMAL":1,
+						"TEXCOORD_0":2
+					},
+					"indices":3,
+					"material":0
+				}
+			]
+		}
+	],
+	"textures":[
+		{
+			"sampler":0,
+			"source":0
+		}
+	],
+	"images":[
+		{
+			"mimeType":"image/png",
+			"name":"checkerboard.ktx2",
+			"uri":"checkerboard.ktx2"
+		}
+	],
+	"accessors":[
+		{
+			"bufferView":0,
+			"componentType":5126,
+			"count":4,
+			"max":[
+				1,
+				0,
+				1
+			],
+			"min":[
+				-1,
+				0,
+				-1
+			],
+			"type":"VEC3"
+		},
+		{
+			"bufferView":1,
+			"componentType":5126,
+			"count":4,
+			"type":"VEC3"
+		},
+		{
+			"bufferView":2,
+			"componentType":5126,
+			"count":4,
+			"type":"VEC2"
+		},
+		{
+			"bufferView":3,
+			"componentType":5123,
+			"count":6,
+			"type":"SCALAR"
+		}
+	],
+	"bufferViews":[
+		{
+			"buffer":0,
+			"byteLength":48,
+			"byteOffset":0,
+			"target":34962
+		},
+		{
+			"buffer":0,
+			"byteLength":48,
+			"byteOffset":48,
+			"target":34962
+		},
+		{
+			"buffer":0,
+			"byteLength":32,
+			"byteOffset":96,
+			"target":34962
+		},
+		{
+			"buffer":0,
+			"byteLength":12,
+			"byteOffset":128,
+			"target":34963
+		}
+	],
+	"samplers":[
+		{
+			"magFilter":9729,
+			"minFilter":9987
+		}
+	],
+	"buffers":[
+		{
+			"byteLength":140,
+			"uri":"checkerboard.bin"
+		}
+	]
+}

tests/gltf/gltf_override_sampler.rs

@@ -0,0 +1,178 @@
+//! Tests loading the same glTF multiple times but with different values for
+//! `GltfLoaderSettings::override_sampler` and `default_sampler`.
+//!
+//! CAUTION: This test currently fails due to <https://github.com/bevyengine/bevy/issues/18267> -
+//! subsequent loads of the same gltf do not respect the loader settings.
+
+use bevy::{
+    gltf::GltfLoaderSettings,
+    image::{ImageAddressMode, ImageFilterMode, ImageSamplerDescriptor},
+    prelude::*,
+};
+
+fn main() {
+    App::new()
+        .insert_resource(VisibleCombo(KeyCode::Digit1))
+        .add_plugins(DefaultPlugins)
+        .add_systems(Startup, setup)
+        .add_systems(Update, (update_controls, update_camera))
+        .run();
+}
+
+#[derive(Component, Clone)]
+struct Combo {
+    key: KeyCode,
+    label: &'static str,
+    sampler: ImageSamplerDescriptor,
+}
+
+fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
+    let default_sampler = ImageSamplerDescriptor {
+        address_mode_u: ImageAddressMode::Repeat,
+        address_mode_v: ImageAddressMode::Repeat,
+        mag_filter: ImageFilterMode::Linear,
+        min_filter: ImageFilterMode::Linear,
+        mipmap_filter: ImageFilterMode::Nearest,
+        ..Default::default()
+    };
+
+    // Declare combinations of sampler settings linked to a key code.
+
+    let combos: &[Combo] = &[
+        Combo {
+            key: KeyCode::Digit1,
+            label: "1: None",
+            sampler: ImageSamplerDescriptor {
+                lod_max_clamp: 0.0,
+                ..default_sampler.clone()
+            },
+        },
+        Combo {
+            key: KeyCode::Digit2,
+            label: "2: Nearest",
+            sampler: default_sampler.clone(),
+        },
+        Combo {
+            key: KeyCode::Digit3,
+            label: "3: Linear",
+            sampler: ImageSamplerDescriptor {
+                mipmap_filter: ImageFilterMode::Linear,
+                ..default_sampler.clone()
+            },
+        },
+        Combo {
+            key: KeyCode::Digit4,
+            label: "4: Linear, Anisotropic",
+            sampler: ImageSamplerDescriptor {
+                mipmap_filter: ImageFilterMode::Linear,
+                anisotropy_clamp: 16,
+                ..default_sampler.clone()
+            },
+        },
+    ];
+
+    // Spawn each combination.
+
+    for combo in combos.iter() {
+        let asset = GltfAssetLabel::Scene(0).from_asset("models/checkerboard/checkerboard.gltf");
+
+        let sampler = combo.sampler.clone();
+
+        let settings = move |settings: &mut GltfLoaderSettings| {
+            settings.default_sampler = Some(sampler.clone());
+            settings.override_sampler = true;
+        };
+
+        commands.spawn((
+            SceneRoot(asset_server.load_with_settings(asset, settings)),
+            combo.clone(),
+        ));
+    }
+
+    // Spawn camera and text.
+
+    commands.spawn((
+        Camera3d::default(),
+        Projection::from(PerspectiveProjection {
+            near: 0.001,
+            ..Default::default()
+        }),
+    ));
+
+    commands.spawn((
+        Text::default(),
+        Node {
+            position_type: PositionType::Absolute,
+            top: Val::Px(12.0),
+            left: Val::Px(12.0),
+            ..Default::default()
+        },
+    ));
+}
+
+#[derive(Resource, PartialEq)]
+struct VisibleCombo(KeyCode);
+
+fn update_controls(
+    mut text: Single<&mut Text>,
+    keyboard_input: Res<ButtonInput<KeyCode>>,
+    mut time: ResMut<Time<Virtual>>,
+    mut combos: Query<(&Combo, &mut Visibility)>,
+    mut visible_combo: ResMut<VisibleCombo>,
+) {
+    // Update combo visibility.
+
+    for (combo, _) in &combos {
+        if keyboard_input.just_pressed(combo.key) {
+            *visible_combo = VisibleCombo(combo.key);
+        }
+    }
+
+    for (combo, mut visibility) in &mut combos {
+        *visibility = if *visible_combo == VisibleCombo(combo.key) {
+            Visibility::Visible
+        } else {
+            Visibility::Hidden
+        };
+    }
+
+    // Update pause.
+
+    if keyboard_input.just_pressed(KeyCode::Space) {
+        if time.is_paused() {
+            time.unpause();
+        } else {
+            time.pause();
+        }
+    }
+
+    // Update help text.
+
+    text.clear();
+
+    text.push_str(&format!(
+        "Space: {}\n\n",
+        if time.is_paused() { "Unpause" } else { "Pause" }
+    ));
+
+    text.push_str("Mipmap filter:\n");
+
+    for (combo, _) in &combos {
+        let visible = *visible_combo == VisibleCombo(combo.key);
+
+        text.push_str(&format!(
+            "{}{}\n",
+            if visible { "> " } else { "  " },
+            combo.label,
+        ));
+    }
+}
+
+fn update_camera(time: Res<Time>, mut query: Query<&mut Transform, With<Camera3d>>) {
+    for mut transform in &mut query {
+        let height = (ops::sin(time.elapsed_secs()) * 0.07) + 0.08;
+
+        *transform =
+            Transform::from_xyz(0.2, height, 0.95).looking_at(Vec3::new(0.0, -0.1, 0.0), Vec3::Y);
+    }
+}