diff --git a/crates/bevy_gltf_blueprints/src/lib.rs b/crates/bevy_gltf_blueprints/src/lib.rs
index 366f05f..78642cd 100644
--- a/crates/bevy_gltf_blueprints/src/lib.rs
+++ b/crates/bevy_gltf_blueprints/src/lib.rs
@@ -120,6 +120,9 @@ impl Plugin for BlueprintsPlugin {
         .register_type::<MaterialInfo>()
         .register_type::<SpawnHere>()
         .register_type::<Animations>()
+        .register_type::<BlueprintsList>()
+        .register_type::<Vec<String>>()
+        .register_type::<HashMap<String, Vec<String>>>()
         .insert_resource(BluePrintsConfig {
             format: self.format,
             library_folder: self.library_folder.clone(),
@@ -140,11 +143,24 @@ impl Plugin for BlueprintsPlugin {
         .add_systems(
             Update,
             (
-                spawn_from_blueprints,
-                compute_scene_aabbs.run_if(aabbs_enabled),
-                apply_deferred.run_if(aabbs_enabled),
+                (
+                    prepare_blueprints,
+                    check_for_loaded,
+                    spawn_from_blueprints,
+                    apply_deferred,
+                )
+                    .chain(),
+                (compute_scene_aabbs, apply_deferred)
+                    .chain()
+                    .run_if(aabbs_enabled),
                 apply_deferred,
-                materials_inject.run_if(materials_library_enabled),
+                (
+                    materials_inject,
+                    check_for_material_loaded,
+                    materials_inject2,
+                )
+                    .chain()
+                    .run_if(materials_library_enabled),
             )
                 .chain()
                 .in_set(GltfBlueprintsSet::Spawn),
diff --git a/crates/bevy_gltf_blueprints/src/materials.rs b/crates/bevy_gltf_blueprints/src/materials.rs
index 5f0140a..030ee90 100644
--- a/crates/bevy_gltf_blueprints/src/materials.rs
+++ b/crates/bevy_gltf_blueprints/src/materials.rs
@@ -4,6 +4,7 @@ use bevy::{
     asset::{AssetServer, Assets, Handle},
     ecs::{
         component::Component,
+        entity::Entity,
         query::{Added, With},
         reflect::ReflectComponent,
         system::{Commands, Query, Res, ResMut},
@@ -16,7 +17,7 @@ use bevy::{
     render::mesh::Mesh,
 };
 
-use crate::BluePrintsConfig;
+use crate::{AssetLoadTracker, AssetsToLoad, BluePrintsConfig};
 
 #[derive(Component, Reflect, Default, Debug)]
 #[reflect(Component)]
@@ -26,10 +27,113 @@ pub struct MaterialInfo {
     pub source: String,
 }
 
+/// flag component
+#[derive(Component)]
+pub(crate) struct BlueprintMaterialAssetsLoaded;
+/// flag component
+#[derive(Component)]
+pub(crate) struct BlueprintMaterialAssetsNotLoaded;
+
 /// system that injects / replaces materials from material library
 pub(crate) fn materials_inject(
+    blueprints_config: ResMut<BluePrintsConfig>,
+    material_infos: Query<(Entity, &MaterialInfo), Added<MaterialInfo>>,
+    asset_server: Res<AssetServer>,
+    mut commands: Commands,
+) {
+    for (entity, material_info) in material_infos.iter() {
+        let model_file_name = format!(
+            "{}_materials_library.{}",
+            &material_info.source, &blueprints_config.format
+        );
+        let materials_path = Path::new(&blueprints_config.material_library_folder)
+            .join(Path::new(model_file_name.as_str()));
+        let material_name = &material_info.name;
+        let material_full_path = materials_path.to_str().unwrap().to_string() + "#" + material_name; // TODO: yikes, cleanup
+
+        if blueprints_config
+            .material_library_cache
+            .contains_key(&material_full_path)
+        {
+            debug!("material is cached, retrieving");
+            blueprints_config
+                .material_library_cache
+                .get(&material_full_path)
+                .expect("we should have the material available");
+            commands
+                .entity(entity)
+                .insert(BlueprintMaterialAssetsLoaded);
+        } else {
+            let material_file_handle: Handle<Gltf> = asset_server.load(materials_path.clone());
+            let material_file_id = material_file_handle.id();
+            let asset_infos: Vec<AssetLoadTracker<Gltf>> = vec![
+                AssetLoadTracker {
+                    name: material_full_path,
+                    id: material_file_id,
+                    loaded: false,
+                    handle: material_file_handle.clone(),
+                }
+            ];
+
+            commands
+                .entity(entity)
+                .insert(AssetsToLoad {
+                    all_loaded: false,
+                    asset_infos,
+                    ..Default::default()
+                })
+                .insert(BlueprintMaterialAssetsNotLoaded);
+            /**/
+        }
+    }
+}
+
+// TODO, merge with check_for_loaded, make generic ?
+pub(crate) fn check_for_material_loaded(
+    mut blueprint_assets_to_load: Query<
+        (Entity, &mut AssetsToLoad<Gltf>),
+        With<BlueprintMaterialAssetsNotLoaded>,
+    >,
+    asset_server: Res<AssetServer>,
+    mut commands: Commands,
+) {
+    for (entity, mut assets_to_load) in blueprint_assets_to_load.iter_mut() {
+        let mut all_loaded = true;
+        let mut loaded_amount = 0;
+        let total = assets_to_load.asset_infos.len();
+        for tracker in assets_to_load.asset_infos.iter_mut() {
+            let asset_id = tracker.id;
+            let loaded = asset_server.is_loaded_with_dependencies(asset_id);
+            tracker.loaded = loaded;
+            if loaded {
+                loaded_amount += 1;
+            } else {
+                all_loaded = false;
+            }
+        }
+        let progress: f32 = loaded_amount as f32 / total as f32;
+        assets_to_load.progress = progress;
+
+        if all_loaded {
+            assets_to_load.all_loaded = true;
+            commands
+                .entity(entity)
+                .insert(BlueprintMaterialAssetsLoaded)
+                .remove::<BlueprintMaterialAssetsNotLoaded>();
+        }
+    }
+}
+
+/// system that injects / replaces materials from material library
+pub(crate) fn materials_inject2(
     mut blueprints_config: ResMut<BluePrintsConfig>,
-    material_infos: Query<(&MaterialInfo, &Children), Added<MaterialInfo>>,
+    material_infos: Query<
+        (&MaterialInfo, &Children),
+        (
+            Added<BlueprintMaterialAssetsLoaded>,
+            With<BlueprintMaterialAssetsLoaded>,
+        ),
+    >,
     with_materials_and_meshes: Query<
         (),
         (
@@ -38,9 +142,9 @@ pub(crate) fn materials_inject(
             With<Handle<Mesh>>,
         ),
     >,
-    models: Res<Assets<bevy::gltf::Gltf>>,
-
+    assets_gltf: Res<Assets<Gltf>>,
     asset_server: Res<AssetServer>,
+
     mut commands: Commands,
 ) {
     for (material_info, children) in material_infos.iter() {
@@ -66,9 +170,9 @@ pub(crate) fn materials_inject(
                 .expect("we should have the material available");
             material_found = Some(material);
         } else {
-            let my_gltf: Handle<Gltf> = asset_server.load(materials_path.clone());
-            let mat_gltf = models
-                .get(my_gltf.id())
+            let model_handle: Handle<Gltf> = asset_server.load(materials_path.clone()); // FIXME: kinda weird now
+            let mat_gltf = assets_gltf
+                .get(model_handle.id())
                 .expect("material should have been preloaded");
             if mat_gltf.named_materials.contains_key(material_name) {
                 let material = mat_gltf
diff --git a/crates/bevy_gltf_blueprints/src/spawn_from_blueprints.rs b/crates/bevy_gltf_blueprints/src/spawn_from_blueprints.rs
index 3701fa5..cf679b7 100644
--- a/crates/bevy_gltf_blueprints/src/spawn_from_blueprints.rs
+++ b/crates/bevy_gltf_blueprints/src/spawn_from_blueprints.rs
@@ -1,6 +1,6 @@
 use std::path::{Path, PathBuf};
 
-use bevy::{gltf::Gltf, prelude::*};
+use bevy::{gltf::Gltf, prelude::*, utils::HashMap};
 
 use crate::{Animations, BluePrintsConfig};
 
@@ -46,8 +46,144 @@ pub struct AddToGameWorld;
 /// helper component, just to transfer child data
 pub(crate) struct OriginalChildren(pub Vec<Entity>);
 
-/// main spawning functions,
+#[derive(Component, Reflect, Default, Debug)]
+#[reflect(Component)]
+pub struct BlueprintsList(pub HashMap<String, Vec<String>>);
+
+#[derive(Default, Debug)]
+pub(crate) struct AssetLoadTracker<T: bevy::prelude::Asset> {
+    #[allow(dead_code)]
+    pub name: String,
+    pub id: AssetId<T>,
+    pub loaded: bool,
+    #[allow(dead_code)]
+    pub handle: Handle<T>,
+}
+#[derive(Component, Debug)]
+pub(crate) struct AssetsToLoad<T: bevy::prelude::Asset> {
+    pub all_loaded: bool,
+    pub asset_infos: Vec<AssetLoadTracker<T>>,
+    pub progress: f32,
+}
+impl <T: bevy::prelude::Asset>Default for AssetsToLoad<T> {
+    fn default() -> Self {
+        Self { all_loaded: Default::default(), asset_infos: Default::default(), progress: Default::default() }
+    }
+}
+
+/// flag component
+#[derive(Component)]
+pub(crate) struct BlueprintAssetsLoaded;
+/// flag component
+#[derive(Component)]
+pub(crate) struct BlueprintAssetsNotLoaded;
+
+/// spawning prepare function,
 /// * also takes into account the already exisiting "override" components, ie "override components" > components from blueprint
+pub(crate) fn prepare_blueprints(
+    spawn_placeholders: Query<
+        (
+            Entity,
+            &BlueprintName,
+            Option<&Parent>,
+            Option<&Library>,
+            Option<&Name>,
+            Option<&BlueprintsList>,
+        ),
+        (Added<BlueprintName>, Added<SpawnHere>, Without<Spawned>),
+    >,
+
+    mut commands: Commands,
+    asset_server: Res<AssetServer>,
+    blueprints_config: Res<BluePrintsConfig>,
+) {
+    for (entity, blupeprint_name, original_parent, library_override, name, blueprints_list) in
+        spawn_placeholders.iter()
+    {
+        debug!(
+            "requesting to spawn {:?} for entity {:?}, id: {:?}, parent:{:?}",
+            blupeprint_name.0, name, entity, original_parent
+        );
+
+        // println!("main model path {:?}", model_path);
+        if blueprints_list.is_some() {
+            let blueprints_list = blueprints_list.unwrap();
+            // println!("blueprints list {:?}", blueprints_list.0.keys());
+            let mut asset_infos: Vec<AssetLoadTracker<Gltf>> = vec![];
+            let library_path =
+                library_override.map_or_else(|| &blueprints_config.library_folder, |l| &l.0);
+            for (blueprint_name, _) in blueprints_list.0.iter() {
+                let model_file_name = format!("{}.{}", &blueprint_name, &blueprints_config.format);
+                let model_path = Path::new(&library_path).join(Path::new(model_file_name.as_str()));
+
+                let model_handle: Handle<Gltf> = asset_server.load(model_path.clone());
+                let model_id = model_handle.id();
+                let loaded = asset_server.is_loaded_with_dependencies(model_id);
+                if !loaded {
+                    asset_infos.push(AssetLoadTracker {
+                        name: model_path.to_string_lossy().into(),
+                        id: model_id,
+                        loaded: false,
+                        handle: model_handle.clone(),
+                    });
+                }
+            }
+            // if not all assets are already loaded, inject a component to signal that we need them to be loaded
+            if !asset_infos.is_empty() {
+                commands
+                    .entity(entity)
+                    .insert(AssetsToLoad {
+                        all_loaded: false,
+                        asset_infos,
+                        ..Default::default()
+                    })
+                    .insert(BlueprintAssetsNotLoaded);
+            } else {
+                commands.entity(entity).insert(BlueprintAssetsLoaded);
+            }
+        } else {
+            // in case there are no blueprintsList
+            commands.entity(entity).insert(BlueprintAssetsLoaded);
+        }
+    }
+}
+
+pub(crate) fn check_for_loaded(
+    mut blueprint_assets_to_load: Query<
+        (Entity, &mut AssetsToLoad<Gltf>),
+        With<BlueprintAssetsNotLoaded>,
+    >,
+    asset_server: Res<AssetServer>,
+    mut commands: Commands,
+) {
+    for (entity, mut assets_to_load) in blueprint_assets_to_load.iter_mut() {
+        let mut all_loaded = true;
+        let mut loaded_amount = 0;
+        let total = assets_to_load.asset_infos.len();
+        for tracker in assets_to_load.asset_infos.iter_mut() {
+            let asset_id = tracker.id;
+            let loaded = asset_server.is_loaded_with_dependencies(asset_id);
+            tracker.loaded = loaded;
+            if loaded {
+                loaded_amount += 1;
+            } else {
+                all_loaded = false;
+            }
+        }
+        let progress: f32 = loaded_amount as f32 / total as f32;
+        // println!("progress: {}",progress);
+        assets_to_load.progress = progress;
+
+        if all_loaded {
+            assets_to_load.all_loaded = true;
+            commands
+                .entity(entity)
+                .insert(BlueprintAssetsLoaded)
+                .remove::<BlueprintAssetsNotLoaded>();
+        }
+    }
+}
+
 pub(crate) fn spawn_from_blueprints(
     spawn_placeholders: Query<
         (
@@ -59,7 +195,11 @@ pub(crate) fn spawn_from_blueprints(
             Option<&AddToGameWorld>,
             Option<&Name>,
         ),
-        (Added<BlueprintName>, Added<SpawnHere>, Without<Spawned>),
+        (
+            With<BlueprintAssetsLoaded>,
+            Added<BlueprintAssetsLoaded>,
+            Without<BlueprintAssetsNotLoaded>,
+        ),
     >,
 
     mut commands: Commands,
@@ -81,18 +221,11 @@ pub(crate) fn spawn_from_blueprints(
         name,
     ) in spawn_placeholders.iter()
     {
-        debug!(
-            "need to spawn {:?} for entity {:?}, id: {:?}, parent:{:?}",
+        info!(
+            "attempting to spawn {:?} for entity {:?}, id: {:?}, parent:{:?}",
             blupeprint_name.0, name, entity, original_parent
         );
 
-        let mut original_children: Vec<Entity> = vec![];
-        if let Ok(c) = children.get(entity) {
-            for child in c.iter() {
-                original_children.push(*child);
-            }
-        }
-
         let what = &blupeprint_name.0;
         let model_file_name = format!("{}.{}", &what, &blueprints_config.format);
 
@@ -101,8 +234,8 @@ pub(crate) fn spawn_from_blueprints(
             library_override.map_or_else(|| &blueprints_config.library_folder, |l| &l.0);
         let model_path = Path::new(&library_path).join(Path::new(model_file_name.as_str()));
 
-        debug!("attempting to spawn {:?}", model_path);
-        let model_handle: Handle<Gltf> = asset_server.load(model_path);
+        // info!("attempting to spawn {:?}", model_path);
+        let model_handle: Handle<Gltf> = asset_server.load(model_path); // FIXME: kinda weird now
 
         let gltf = assets_gltf
             .get(&model_handle)
@@ -123,6 +256,12 @@ pub(crate) fn spawn_from_blueprints(
             transforms = *transform.unwrap();
         }
 
+        let mut original_children: Vec<Entity> = vec![];
+        if let Ok(c) = children.get(entity) {
+            for child in c.iter() {
+                original_children.push(*child);
+            }
+        }
         commands.entity(entity).insert((
             SceneBundle {
                 scene: scene.clone(),
diff --git a/crates/bevy_gltf_blueprints/src/spawn_post_process.rs b/crates/bevy_gltf_blueprints/src/spawn_post_process.rs
index 2caa625..b53f4d7 100644
--- a/crates/bevy_gltf_blueprints/src/spawn_post_process.rs
+++ b/crates/bevy_gltf_blueprints/src/spawn_post_process.rs
@@ -1,12 +1,16 @@
 use std::any::TypeId;
 
+use bevy::gltf::Gltf;
 use bevy::prelude::*;
 use bevy::scene::SceneInstance;
 // use bevy::utils::hashbrown::HashSet;
 
 use super::{AnimationPlayerLink, Animations};
 use super::{SpawnHere, Spawned};
-use crate::{CopyComponents, InBlueprint, NoInBlueprint, OriginalChildren};
+use crate::{
+    AssetsToLoad, BlueprintAssetsLoaded, CopyComponents, InBlueprint, NoInBlueprint,
+    OriginalChildren,
+};
 
 /// this system is in charge of doing any necessary post processing after a blueprint scene has been spawned
 /// - it removes one level of useless nesting
@@ -89,6 +93,8 @@ pub(crate) fn spawned_blueprint_post_process(
         commands.entity(original).remove::<SpawnHere>();
         commands.entity(original).remove::<Spawned>();
         commands.entity(original).remove::<Handle<Scene>>();
+        commands.entity(original).remove::<AssetsToLoad<Gltf>>(); // also clear the sub assets tracker to free up handles, perhaps just freeing up the handles and leave the rest would be better ?
+        commands.entity(original).remove::<BlueprintAssetsLoaded>();
         commands.entity(root_entity).despawn_recursive();
     }
 }
diff --git a/examples/bevy_gltf_blueprints/animation/src/game/in_game.rs b/examples/bevy_gltf_blueprints/animation/src/game/in_game.rs
index fcf711b..454ce27 100644
--- a/examples/bevy_gltf_blueprints/animation/src/game/in_game.rs
+++ b/examples/bevy_gltf_blueprints/animation/src/game/in_game.rs
@@ -30,7 +30,7 @@ pub fn setup_game(
         SceneBundle {
             // note: because of this issue https://github.com/bevyengine/bevy/issues/10436, "world" is now a gltf file instead of a scene
             scene: models
-                .get(game_assets.world.id())
+                .get(game_assets.world.clone().unwrap().id())
                 .expect("main level should have been loaded")
                 .scenes[0]
                 .clone(),
diff --git a/examples/bevy_gltf_blueprints/basic/src/game/in_game.rs b/examples/bevy_gltf_blueprints/basic/src/game/in_game.rs
index 3af11d5..231137b 100644
--- a/examples/bevy_gltf_blueprints/basic/src/game/in_game.rs
+++ b/examples/bevy_gltf_blueprints/basic/src/game/in_game.rs
@@ -20,7 +20,7 @@ pub fn setup_game(
         SceneBundle {
             // note: because of this issue https://github.com/bevyengine/bevy/issues/10436, "world" is now a gltf file instead of a scene
             scene: models
-                .get(game_assets.world.id())
+                .get(game_assets.world.clone().unwrap().id())
                 .expect("main level should have been loaded")
                 .scenes[0]
                 .clone(),
diff --git a/examples/bevy_gltf_blueprints/basic_xpbd_physics/src/game/in_game.rs b/examples/bevy_gltf_blueprints/basic_xpbd_physics/src/game/in_game.rs
index 3fa60da..6853655 100644
--- a/examples/bevy_gltf_blueprints/basic_xpbd_physics/src/game/in_game.rs
+++ b/examples/bevy_gltf_blueprints/basic_xpbd_physics/src/game/in_game.rs
@@ -20,7 +20,7 @@ pub fn setup_game(
         SceneBundle {
             // note: because of this issue https://github.com/bevyengine/bevy/issues/10436, "world" is now a gltf file instead of a scene
             scene: models
-                .get(game_assets.world.id())
+                .get(game_assets.world.clone().unwrap().id())
                 .expect("main level should have been loaded")
                 .scenes[0]
                 .clone(),
diff --git a/examples/bevy_gltf_blueprints/materials/src/game/in_game.rs b/examples/bevy_gltf_blueprints/materials/src/game/in_game.rs
index e5fc8b8..6bdf1d9 100644
--- a/examples/bevy_gltf_blueprints/materials/src/game/in_game.rs
+++ b/examples/bevy_gltf_blueprints/materials/src/game/in_game.rs
@@ -21,7 +21,7 @@ pub fn setup_game(
         SceneBundle {
             // note: because of this issue https://github.com/bevyengine/bevy/issues/10436, "world" is now a gltf file instead of a scene
             scene: models
-                .get(game_assets.world.id())
+                .get(game_assets.world.clone().unwrap().id())
                 .expect("main level should have been loaded")
                 .scenes[0]
                 .clone(),
diff --git a/examples/bevy_gltf_blueprints/multiple_levels_multiple_blendfiles/src/game/in_game.rs b/examples/bevy_gltf_blueprints/multiple_levels_multiple_blendfiles/src/game/in_game.rs
index 75be98a..11ee36d 100644
--- a/examples/bevy_gltf_blueprints/multiple_levels_multiple_blendfiles/src/game/in_game.rs
+++ b/examples/bevy_gltf_blueprints/multiple_levels_multiple_blendfiles/src/game/in_game.rs
@@ -21,7 +21,7 @@ pub fn setup_game(
         SceneBundle {
             // note: because of this issue https://github.com/bevyengine/bevy/issues/10436, "world" is now a gltf file instead of a scene
             scene: models
-                .get(game_assets.world.id())
+                .get(game_assets.world.clone().unwrap().id())
                 .expect("main level should have been loaded")
                 .scenes[0]
                 .clone(),
diff --git a/examples/bevy_gltf_blueprints/multiple_levels_multiple_blendfiles/src/game/level_transitions.rs b/examples/bevy_gltf_blueprints/multiple_levels_multiple_blendfiles/src/game/level_transitions.rs
index 41d5c90..4dcb69c 100644
--- a/examples/bevy_gltf_blueprints/multiple_levels_multiple_blendfiles/src/game/level_transitions.rs
+++ b/examples/bevy_gltf_blueprints/multiple_levels_multiple_blendfiles/src/game/level_transitions.rs
@@ -76,7 +76,7 @@ pub fn trigger_level_transition(
                     } else if target_level == "Level2" {
                         level = game_assets.level2.clone().unwrap();
                     } else {
-                        level = game_assets.world.clone();
+                        level = game_assets.world.clone().unwrap();
                     }
                     info!("spawning new level");
                     commands.spawn((
diff --git a/examples/bevy_registry_export/basic/src/game/in_game.rs b/examples/bevy_registry_export/basic/src/game/in_game.rs
index 75be98a..11ee36d 100644
--- a/examples/bevy_registry_export/basic/src/game/in_game.rs
+++ b/examples/bevy_registry_export/basic/src/game/in_game.rs
@@ -21,7 +21,7 @@ pub fn setup_game(
         SceneBundle {
             // note: because of this issue https://github.com/bevyengine/bevy/issues/10436, "world" is now a gltf file instead of a scene
             scene: models
-                .get(game_assets.world.id())
+                .get(game_assets.world.clone().unwrap().id())
                 .expect("main level should have been loaded")
                 .scenes[0]
                 .clone(),
diff --git a/examples/common/src/assets/assets_game.rs b/examples/common/src/assets/assets_game.rs
index 988e964..5bb5986 100644
--- a/examples/common/src/assets/assets_game.rs
+++ b/examples/common/src/assets/assets_game.rs
@@ -5,8 +5,8 @@ use bevy_asset_loader::prelude::*;
 
 #[derive(AssetCollection, Resource)]
 pub struct GameAssets {
-    #[asset(key = "world")]
-    pub world: Handle<Gltf>,
+    #[asset(key = "world", optional)]
+    pub world: Option<Handle<Gltf>>,
 
     #[asset(key = "world_dynamic", optional)]
     pub world_dynamic: Option<Handle<Gltf>>,
@@ -16,8 +16,8 @@ pub struct GameAssets {
     #[asset(key = "level2", optional)]
     pub level2: Option<Handle<Gltf>>,
 
-    #[asset(key = "models", collection(typed, mapped))]
-    pub models: HashMap<String, Handle<Gltf>>,
+    #[asset(key = "models", collection(typed, mapped), optional)]
+    pub models: Option<HashMap<String, Handle<Gltf>>>,
 
     #[asset(key = "materials", collection(typed, mapped), optional)]
     pub materials: Option<HashMap<String, Handle<Gltf>>>,
diff --git a/testing/bevy_example/assets/assets_game.assets.ron b/testing/bevy_example/assets/assets_game.assets.ron
index 5b1e969..40825c0 100644
--- a/testing/bevy_example/assets/assets_game.assets.ron
+++ b/testing/bevy_example/assets/assets_game.assets.ron
@@ -1,6 +1,6 @@
 ({
-    "world":File (path: "models/World.glb"),
+    /*"world":File (path: "models/World.glb"),
     "models": Folder (
         path: "models/library",
-    ),
+    ),*/
 })
\ No newline at end of file
diff --git a/testing/bevy_example/assets/registry.json b/testing/bevy_example/assets/registry.json
index 65dea5f..33887c3 100644
--- a/testing/bevy_example/assets/registry.json
+++ b/testing/bevy_example/assets/registry.json
@@ -3576,6 +3576,22 @@
       "type": "array",
       "typeInfo": "TupleStruct"
     },
+    "bevy_gltf_blueprints::spawn_from_blueprints::BlueprintsList": {
+      "isComponent": true,
+      "isResource": false,
+      "items": false,
+      "prefixItems": [
+        {
+          "type": {
+            "$ref": "#/$defs/bevy_utils::hashbrown::HashMap<alloc::string::String, alloc::vec::Vec<alloc::string::String>, bevy_utils::hashbrown::hash_map::DefaultHashBuilder>"
+          }
+        }
+      ],
+      "short_name": "BlueprintsList",
+      "title": "bevy_gltf_blueprints::spawn_from_blueprints::BlueprintsList",
+      "type": "array",
+      "typeInfo": "TupleStruct"
+    },
     "bevy_gltf_blueprints::spawn_from_blueprints::SpawnHere": {
       "additionalProperties": false,
       "isComponent": true,
@@ -10834,6 +10850,19 @@
       "type": "object",
       "typeInfo": "Value"
     },
+    "bevy_utils::hashbrown::HashMap<alloc::string::String, alloc::vec::Vec<alloc::string::String>, bevy_utils::hashbrown::hash_map::DefaultHashBuilder>": {
+      "additionalProperties": {
+        "type": {
+          "$ref": "#/$defs/alloc::vec::Vec<alloc::string::String>"
+        }
+      },
+      "isComponent": false,
+      "isResource": false,
+      "short_name": "HashMap<String, Vec<String>, DefaultHashBuilder>",
+      "title": "bevy_utils::hashbrown::HashMap<alloc::string::String, alloc::vec::Vec<alloc::string::String>, bevy_utils::hashbrown::hash_map::DefaultHashBuilder>",
+      "type": "object",
+      "typeInfo": "Map"
+    },
     "bevy_utils::smallvec::SmallVec<[bevy_ecs::entity::Entity; 8]>": {
       "isComponent": false,
       "isResource": false,
diff --git a/testing/bevy_example/src/core/mod.rs b/testing/bevy_example/src/core/mod.rs
index 1ef7f3e..339ea40 100644
--- a/testing/bevy_example/src/core/mod.rs
+++ b/testing/bevy_example/src/core/mod.rs
@@ -11,6 +11,7 @@ impl Plugin for CorePlugin {
                 legacy_mode: false,
                 library_folder: "models/library".into(),
                 format: GltfFormat::GLB,
+                material_library: true,
                 aabbs: true,
                 ..Default::default()
             },
diff --git a/testing/bevy_example/src/game/in_game.rs b/testing/bevy_example/src/game/in_game.rs
index 75be98a..4873f4e 100644
--- a/testing/bevy_example/src/game/in_game.rs
+++ b/testing/bevy_example/src/game/in_game.rs
@@ -1,37 +1,27 @@
 use bevy::prelude::*;
-use bevy_gltf_blueprints::{BluePrintBundle, BlueprintName, GameWorldTag};
-use bevy_gltf_worlflow_examples_common_rapier::{assets::GameAssets, GameState, InAppRunning};
+use bevy_gltf_blueprints::{
+    BluePrintBundle, BlueprintName, GameWorldTag,
+};
+use bevy_gltf_worlflow_examples_common_rapier::{GameState, InAppRunning};
 
 use bevy_rapier3d::prelude::Velocity;
 use rand::Rng;
 
 pub fn setup_game(
     mut commands: Commands,
-    game_assets: Res<GameAssets>,
-    models: Res<Assets<bevy::gltf::Gltf>>,
+    asset_server: Res<AssetServer>,
     mut next_game_state: ResMut<NextState<GameState>>,
 ) {
-    commands.insert_resource(AmbientLight {
-        color: Color::WHITE,
-        brightness: 0.2,
-    });
     // here we actually spawn our game world/level
-
     commands.spawn((
         SceneBundle {
-            // note: because of this issue https://github.com/bevyengine/bevy/issues/10436, "world" is now a gltf file instead of a scene
-            scene: models
-                .get(game_assets.world.id())
-                .expect("main level should have been loaded")
-                .scenes[0]
-                .clone(),
+            scene: asset_server.load("models/World.glb#Scene0"),
             ..default()
         },
         bevy::prelude::Name::from("world"),
         GameWorldTag,
         InAppRunning,
     ));
-
     next_game_state.set(GameState::InGame)
 }
 
diff --git a/testing/bevy_example/src/game/mod.rs b/testing/bevy_example/src/game/mod.rs
index 99b9b3f..2cd7144 100644
--- a/testing/bevy_example/src/game/mod.rs
+++ b/testing/bevy_example/src/game/mod.rs
@@ -97,9 +97,10 @@ impl Plugin for GamePlugin {
     fn build(&self, app: &mut App) {
         app.add_systems(Update, (spawn_test).run_if(in_state(GameState::InGame)))
             .add_systems(Update, validate_export)
-            .add_systems(Update, generate_screenshot.run_if(on_timer(Duration::from_secs_f32(0.2)))) // TODO: run once
             .add_systems(OnEnter(AppState::MenuRunning), start_game)
             .add_systems(OnEnter(AppState::AppRunning), setup_game)
+            
+            .add_systems(Update, generate_screenshot.run_if(on_timer(Duration::from_secs_f32(0.2)))) // TODO: run once
             .add_systems(
                 Update,
                 exit_game.run_if(on_timer(Duration::from_secs_f32(0.5))),
diff --git a/tools/gltf_auto_export/auto_export/export_main_scenes.py b/tools/gltf_auto_export/auto_export/export_main_scenes.py
index 8bdb018..25cfd37 100644
--- a/tools/gltf_auto_export/auto_export/export_main_scenes.py
+++ b/tools/gltf_auto_export/auto_export/export_main_scenes.py
@@ -4,7 +4,7 @@ import bpy
 from ..helpers.generate_and_export import generate_and_export
 from .export_gltf import (generate_gltf_export_preferences, export_gltf)
 from ..modules.bevy_dynamic import is_object_dynamic, is_object_static
-from ..helpers.helpers_scenes import clear_hollow_scene, copy_hollowed_collection_into
+from ..helpers.helpers_scenes import clear_hollow_scene, copy_hollowed_collection_into, inject_blueprints_list_into_main_scene
 
 
 # export all main scenes
@@ -29,6 +29,8 @@ def export_main_scene(scene, folder_path, addon_prefs, library_collections):
                        }
 
     if export_blueprints : 
+        inject_blueprints_list_into_main_scene(scene)
+
         if export_separate_dynamic_and_static_objects:
             #print("SPLIT STATIC AND DYNAMIC")
             # first export static objects
diff --git a/tools/gltf_auto_export/helpers/helpers_collections.py b/tools/gltf_auto_export/helpers/helpers_collections.py
index edb3214..219add2 100644
--- a/tools/gltf_auto_export/helpers/helpers_collections.py
+++ b/tools/gltf_auto_export/helpers/helpers_collections.py
@@ -36,16 +36,23 @@ def get_marked_collections(scene, addon_prefs):
     return (collection_names, marked_collections)
 
 # gets all collections within collections that might also be relevant
-def get_sub_collections(collections, parent, children_per_collection):
+def get_sub_collections(collections, parent=None, children_per_collection=None):
+    if parent == None:
+        parent = CollectionNode()
+    if children_per_collection == None:
+        children_per_collection = {}
+
     collection_names = set()
     used_collections = []
     
     for root_collection in collections:
-        node = Node(name=root_collection.name, parent=parent)
+        #print("collections", collections)
+        node = CollectionNode(name=root_collection.name, parent=parent)
         parent.children.append(node)
 
         #print("root collection", root_collection.name)
         for collection in traverse_tree(root_collection): # TODO: filter out COLLECTIONS that have the flatten flag (unlike the flatten flag on colleciton instances themselves)
+            #print("sub", collection)
             node_name = collection.name
             children_per_collection[node_name] = []
             #print("  scanning", collection.name)
@@ -53,12 +60,15 @@ def get_sub_collections(collections, parent, children_per_collection):
                 #print("FLATTEN", object.name, 'Flatten' in object)
                 if object.instance_type == 'COLLECTION' : # and not 'Flatten' in object: 
                     collection_name = object.instance_collection.name
+                    #print("sub obj", collection_name)
+                    # FIXME: not sure:
+                    children_per_collection[node_name].append(collection_name)
+
                     (sub_names, sub_collections) = get_sub_collections([object.instance_collection], node, children_per_collection)
                     if len(list(sub_names)) > 0:
                         children_per_collection[node_name]  += (list(sub_names))
                     #print("   found sub collection in use", object.name, object.instance_collection)
 
-
                     if not collection_name in collection_names: 
                         collection_names.add(collection_name)
                         used_collections.append(object.instance_collection)
@@ -77,7 +87,7 @@ def flatten_collection_tree(node, children_per_collection):
     children_per_collection[node.name] = list(set( children_per_collection[node.name]))
        
 
-class Node :
+class CollectionNode :
     def __init__(self, name="", parent=None):
       self.name = name
       self.children = []
@@ -93,7 +103,7 @@ def get_exportable_collections(main_scenes, library_scenes, addon_prefs):
 
     all_collections = []
     all_collection_names = []
-    root_node = Node()
+    root_node = CollectionNode()
     root_node.name = "root"
     children_per_collection = {}
 
diff --git a/tools/gltf_auto_export/helpers/helpers_scenes.py b/tools/gltf_auto_export/helpers/helpers_scenes.py
index e5b4dfb..6275231 100644
--- a/tools/gltf_auto_export/helpers/helpers_scenes.py
+++ b/tools/gltf_auto_export/helpers/helpers_scenes.py
@@ -1,5 +1,6 @@
+import json
 import bpy
-from .helpers_collections import (set_active_collection)
+from .helpers_collections import (CollectionNode, get_sub_collections, get_used_collections, set_active_collection)
 from .object_makers import (make_empty)
 
 
@@ -72,6 +73,13 @@ def copy_hollowed_collection_into(source_collection, destination_collection, par
             """we inject the collection/blueprint name, as a component called 'BlueprintName', but we only do this in the empty, not the original object"""
             empty_obj['BlueprintName'] = '"'+collection_name+'"' if legacy_mode else '("'+collection_name+'")'
             empty_obj['SpawnHere'] = '()'
+            # we also inject a list of all sub blueprints, so that the bevy side can preload them
+            root_node = CollectionNode()
+            root_node.name = "root"
+            children_per_collection = {}
+            get_sub_collections([object.instance_collection], root_node, children_per_collection)
+            empty_obj["BlueprintsList"] = f"({json.dumps(dict(children_per_collection))})"
+            #empty_obj["Assets"] = {"Animations": [], "Materials": [], "Models":[], "Textures":[], "Audio":[], "Other":[]}
 
             # we copy custom properties over from our original object to our empty
             for component_name, component_value in object.items():
@@ -149,3 +157,35 @@ def get_scenes(addon_prefs):
     return [level_scene_names, level_scenes, library_scene_names, library_scenes]
 
 
+
+
+def inject_blueprints_list_into_main_scene(scene):
+    print("injecting assets/blueprints data into scene")
+    root_collection = scene.collection
+    assets_list = None
+    for object in scene.objects:
+        if object.name == "assets_list"+scene.name:
+            assets_list = object
+            break
+
+    if assets_list is None:
+        assets_list = make_empty('assets_list_'+scene.name+"_components", [0,0,0], [0,0,0], [0,0,0], root_collection)
+
+    # find all blueprints used in a scene
+    # TODO: export a tree rather than a flat list ? because you could have potential clashing items in flat lists (amongst other issues)
+    (collection_names, collections) = get_used_collections(scene)
+    root_node = CollectionNode()
+    root_node.name = "root"
+    children_per_collection = {}
+    
+    #print("collection_names", collection_names, "collections", collections)
+    (bla, bli ) = get_sub_collections(collections, root_node, children_per_collection)
+    # what about marked assets ?
+    # what about audio assets ?
+    # what about materials ?
+    # object['MaterialInfo'] = '(name: "'+material.name+'", source: "'+current_project_name + '")' 
+
+    #assets_list["blueprints_direct"] = list(collection_names)
+    assets_list["BlueprintsList"] = f"({json.dumps(dict(children_per_collection))})"
+    #assets_list["Materials"]= '()'
+    # print("assets list", assets_list["BlueprintsList"], children_per_collection)
diff --git a/tools/gltf_auto_export/tests/test_basic.py b/tools/gltf_auto_export/tests/test_basic.py
index 0ebe949..7d01954 100644
--- a/tools/gltf_auto_export/tests/test_basic.py
+++ b/tools/gltf_auto_export/tests/test_basic.py
@@ -19,6 +19,8 @@ def setup_data(request):
 
     def finalizer():
         print("\nPerforming teardown...")
+        get_orphan_data()
+
         if os.path.exists(models_path):
             shutil.rmtree(models_path)
 
@@ -33,9 +35,14 @@ def setup_data(request):
 
     return None
 
+
+def get_orphan_data():
+    orphan_meshes = [m.name for m in bpy.data.meshes if m.users == 0]
+    # print("orphan meshes before", orphan_meshes)
+
 def test_export_do_not_export_blueprints(setup_data):
     auto_export_operator = bpy.ops.export_scenes.auto_gltf
-
+    
     # first, configure things
     # we use the global settings for that
     export_props = {
@@ -57,7 +64,6 @@ def test_export_do_not_export_blueprints(setup_data):
 
 def test_export_custom_blueprints_path(setup_data):
     auto_export_operator = bpy.ops.export_scenes.auto_gltf
-
     # first, configure things
     # we use the global settings for that
     export_props = {
@@ -210,3 +216,27 @@ def test_export_separate_dynamic_and_static_objects(setup_data):
 
     assert os.path.exists(os.path.join(setup_data["models_path"], "World.glb")) == True
     assert os.path.exists(os.path.join(setup_data["models_path"], "World_dynamic.glb")) == True
+
+
+def test_export_should_not_generate_orphan_data(setup_data):
+    auto_export_operator = bpy.ops.export_scenes.auto_gltf
+    
+    # first, configure things
+    # we use the global settings for that
+    export_props = {
+        "main_scene_names" : ['World'],
+        "library_scene_names": ['Library']
+    }
+    stored_settings = bpy.data.texts[".gltf_auto_export_settings"] if ".gltf_auto_export_settings" in bpy.data.texts else bpy.data.texts.new(".gltf_auto_export_settings")
+    stored_settings.clear()
+    stored_settings.write(json.dumps(export_props))
+
+    auto_export_operator(
+        direct_mode=True,
+        export_output_folder="./models",
+        export_scene_settings=True,
+        export_blueprints=False,
+    )
+    assert os.path.exists(os.path.join(setup_data["models_path"], "World.glb")) == True
+    assert os.path.exists(os.path.join(setup_data["models_path"], "library", "Blueprint1.glb")) == False
+
diff --git a/tools/gltf_auto_export/tests/test_bevy_integration.py b/tools/gltf_auto_export/tests/test_bevy_integration.py
index afd5255..efa30fe 100644
--- a/tools/gltf_auto_export/tests/test_bevy_integration.py
+++ b/tools/gltf_auto_export/tests/test_bevy_integration.py
@@ -16,18 +16,16 @@ def setup_data(request):
         root_path =  "../../testing/bevy_example"
         assets_root_path = os.path.join(root_path, "assets")
         models_path =  os.path.join(assets_root_path, "models")
-        #materials_path = os.path.join("../../testing", "materials")
+        materials_path = os.path.join(assets_root_path, "materials")
         #other_materials_path = os.path.join("../../testing", "other_materials")
 
         print("\nPerforming teardown...")
         if os.path.exists(models_path):
             shutil.rmtree(models_path)
 
-        """if os.path.exists(materials_path):
+        if os.path.exists(materials_path):
             shutil.rmtree(materials_path)
 
-        if os.path.exists(other_materials_path):
-            shutil.rmtree(other_materials_path)"""
         diagnostics_file_path = os.path.join(root_path, "bevy_diagnostics.json")
         if os.path.exists(diagnostics_file_path):
             os.remove(diagnostics_file_path)
@@ -75,7 +73,8 @@ def test_export_complex(setup_data):
         export_scene_settings=True,
         export_blueprints=True,
         export_legacy_mode=False,
-        export_animations=True
+        export_animations=True,
+        export_materials_library=True
     )
     # blueprint1 => has an instance, got changed, should export
     # blueprint2 => has NO instance, but marked as asset, should export
@@ -95,11 +94,7 @@ def test_export_complex(setup_data):
 
     # now run bevy
     command = "cargo run --features bevy/dynamic_linking"
-    # assert getattr(propertyGroup, 'a') == 0.5714026093482971
     FNULL = open(os.devnull, 'w')    #use this if you want to suppress output to stdout from the subprocess
-    filename = "my_file.dat"
-    args = command
-    #subprocess.call(args, stdout=FNULL, stderr=FNULL, shell=False, cwd=bevy_run_exec_path)
     return_code = subprocess.call(["cargo", "run", "--features", "bevy/dynamic_linking"], cwd=root_path)
     print("RETURN CODE OF BEVY APP", return_code)
     assert return_code == 0