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Kielan/custom_material.wgsl

Last active November 26, 2025 20:41
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Revisions

  1. Kielan revised this gist Nov 26, 2025. 1 changed file with 38 additions and 2 deletions.
    40 changes: 38 additions & 2 deletions main.rs
    View file
    Original file line number Diff line number Diff line change
    @@ -140,8 +140,44 @@ impl Material for CustomMaterial {
    fn specialize(
    _pipeline: &MaterialPipeline<Self>,
    descriptor: &mut RenderPipelineDescriptor,
    ) {

    _layout: &MeshVertexBufferLayout,
    key: MaterialPipelineKey<Self>,
    ) -> Result<(), SpecializedMeshPipelineError> {
    descriptor.primitive.cull_mode = None;
    if let Some(label) = &mut descriptor.label {
    *label = format!("shielf_{}", *label).into
    }
    Ok(())
    }
    }

    //Struct that is passed to used shader
    #[derive(AsBindGroup, TypeUuid, Debug, Clone)]
    #[uuid = "f690fdae-d598-45ab-8225-97e2a3f056e0"]
    pub struct CustomMaterial {
    #[uniform(0)]
    time: f32,
    #[uniform(1)]
    color: Color,
    #[texture(2)]
    #[sampler(3)]
    color_texture: Option<Handle>Image>>,
    alpha_mode: AlphaMode,
    }

    fn mod_scene(
    mut commands: Commands,
    spheres: Query<
    (Entity, &Handle<Mesh>, &Name),
    Without<Inserted>,
    >,
    mut meshes: ResMut<Assets<Mesh>>,
    mut custom_materials: ResMut<Assets<CustomMaterial>>,
    asset_server: Res<AssetServer>,
    ) {
    for sphere in spheres.iter() {
    let mesh = meshes.get_mut(sphere.1).unwraph();
    if let Some(VertexAttributeValues)
    }
    }

  2. Kielan revised this gist Nov 26, 2025. 1 changed file with 5 additions and 4 deletions.
    9 changes: 5 additions & 4 deletions main.rs
    View file
    Original file line number Diff line number Diff line change
    @@ -95,11 +95,13 @@ struct GLTFScene;
    struct Inserted;

    //set up a simple 3d scene
    /*
    fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
    fn CustomMaterialGLTFSceneSetup(mut commands: Commands, asset_server: Res<AssetServer>) {
    commands
    .spawn_bundle(SceneBundle {
    scene: asset_server.load(
    "hex-sphere-5-subdivisions.glb#Scene0"
    ),
    ..default()
    })
    .insert(GLTFScene);

    @@ -109,7 +111,6 @@ fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
    ..default()
    });
    }
    */

    fn change_color(
    mut materials: ResMut<Assets<CustomMaterial>>,
  3. Kielan revised this gist Nov 26, 2025. 1 changed file with 48 additions and 1 deletion.
    49 changes: 48 additions & 1 deletion main.rs
    View file
    Original file line number Diff line number Diff line change
    @@ -95,7 +95,54 @@ struct GLTFScene;
    struct Inserted;

    //set up a simple 3d scene
    //fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {}
    /*
    fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
    commands
    .spawn_bundle(SceneBundle {
    })
    .insert(GLTFScene);
    commands.spawn_bundle(Camera3dBundle {
    transform: Transform::from_xyz(-2.0, 2.5, 5.0)
    .looking_at(Vec3::ZERO, Vec3::Y),
    ..default()
    });
    }
    */

    fn change_color(
    mut materials: ResMut<Assets<CustomMaterial>>,
    time: Res<Time>,
    ) {
    for material in materials.iter_mut() {
    material.1.time =
    time.seconds_since_startup() as f32;
    }
    }

    //The Material trait is very configurable and comes w defaults for all methods
    //See Material API
    impl Material for CustomMaterial {
    fn fragment_shader() -> ShaderRef {
    "shaders/custom_material.wgsl".into()
    }

    fn vertex_shader() -> ShaderRef {
    "shaders/vertex_shader.wgsl".into()
    }

    fn alpha_mode(&self) -> AlphaMode {
    self.alpha_mode
    }

    fn specialize(
    _pipeline: &MaterialPipeline<Self>,
    descriptor: &mut RenderPipelineDescriptor,
    ) {

    }
    }

    #[derive(Resource)]
    struct MapHandles {
  4. Kielan revised this gist Nov 26, 2025. 1 changed file with 37 additions and 1 deletion.
    38 changes: 37 additions & 1 deletion main.rs
    View file
    Original file line number Diff line number Diff line change
    @@ -3,10 +3,28 @@
    //https://www.youtube.com/watch?v=i4zImwo_flw&t=5s
    //https://www.youtube.com/watch?v=mGRC567ooAM&list=PL_U1hw01V0ze620DDrUwK2-WtVQI_nsr9&index=38

    /* Applying Bevy 0.8 Custom Materials to GLTF scenes imports*/
    use bevy::{
    pbr::{MaterialPipeline, MaterialPipelineKey},
    prelude::*,
    reflect::TypeUuid,
    render::{
    mesh::{
    MeshVertexBufferLayout, VertexAttributeValues,
    },
    render_resource::{
    AsBindGroup, Face, RenderPipelineDescriptor,
    ShaderRef, SpecializedMeshPipelineError,
    },
    },
    scene::SceneInstance,
    };
    use bevy_shader_utils::ShaderUtilsPlugin;

    mod map_loader;

    use map_loader::*;
    bevy::prelude::*;
    //bevy::prelude::*;
    use roxmltree::*;

    #derive(AsBindGroup, Debug, Clone, TypeUuid)]
    @@ -51,16 +69,34 @@ fn setup(

    fn main() {
    App::new()
    .insert_resource({
    })
    .add_plugins((DefaultPlugins.set(plugin: AssetPlugin {
    mode: Asset<pde::Unprocessed,
    file_path: "res".to_string(),
    ...Default::default()
    }), MapLoaderPlugin)) &mut App
    .add_plugins(ShaderUtilsPlugin)
    .add_plugin(
    MaterialPlugin::<CustomMaterial>::default(),
    )
    .add_startup_system(setup)
    .add_system(change_color)
    .add_system(mod_scene)
    .add_systems(schedule: Startup, systems: setup) &mut App
    .add_systems(shedule: Update, systems: hello_assets) &mut App
    .run();
    }

    #[derive(Component)]
    struct GLTFScene;

    #[derive(Component)]
    struct Inserted;

    //set up a simple 3d scene
    //fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {}

    #[derive(Resource)]
    struct MapHandles {
    maps: Vec<Handle<Map>>
  5. Kielan revised this gist Nov 26, 2025. 1 changed file with 1 addition and 0 deletions.
    1 change: 1 addition & 0 deletions main.rs
    View file
    Original file line number Diff line number Diff line change
    @@ -1,6 +1,7 @@
    //https://github.com/bevyengine/bevy/blob/latest/examples/asset/processing/asset_processing.rs
    //https://www.youtube.com/watch?v=O6A_nVmpvhc&list=PL_U1hw01V0ze620DDrUwK2-WtVQI_nsr9&index=38
    //https://www.youtube.com/watch?v=i4zImwo_flw&t=5s
    //https://www.youtube.com/watch?v=mGRC567ooAM&list=PL_U1hw01V0ze620DDrUwK2-WtVQI_nsr9&index=38

    mod map_loader;

  6. Kielan revised this gist Nov 26, 2025. 2 changed files with 140 additions and 0 deletions.
    35 changes: 35 additions & 0 deletions custom_material.wgsl
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,35 @@
    #import bevy_shader_utils::simplex_noise_3d

    struct CustomMaterial {
    // color: vec4<f32>,
    time: f32,
    };

    @group(1) @binding(0)
    var<uniform> material: CustomMaterial;
    @group(1) @binding(1)
    var base_color_texture: texture_2d<f32>;
    @group(1) @binding(2)
    var base_color_sampler: sampler;

    @fragment
    fn fragment(
    @builtin(front_facing) is_front: bool,
    @builtin(position) frag_coord: vec4<f32>,
    @location(0) world_position: vec4<f32>,
    @location(1) world_normal: vec3<f32>,
    @location(2) uv: vec2<f32>,
    #ifdef VERTEX_COLORS
    @location(4) color: vec4<f32>,
    #endif
    ) -> @location(0) vec4<f32> {
    // return material.color * textureSample(base_color_texture, base_color_sampler, uv);
    // var input: vec3<f32> = vec3<f32>(uv.x * 40.0, uv.y * 40.0, 1.);
    var noise = simplexNoise3(vec3<f32>(world_normal.xyz * 2.0));
    var alpha = (noise + 1.0) / 2.0;
    // return material.color * textureSample(base_color_texture, base_color_sampler, uv) * vec4<f32>(1.0, 1.0, 1.0, alpha);
    // return material.color * vec4<f32>(1.0, 1.0, 1.0, alpha);
    // return vec4<f32>(uv.x, uv.y, 0.0, 1.0);

    return vec4<f32>(world_normal.xyz, smoothstep(-1.0, 3.0, noise));
    }
    105 changes: 105 additions & 0 deletions vertext_shader.wgsl
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,105 @@
    #import bevy_pbr::mesh_view_bindings
    #import bevy_pbr::mesh_bindings

    // NOTE: Bindings must come before functions that use them!
    #import bevy_pbr::mesh_functions

    #import bevy_shader_utils::simplex_noise_3d
    #import bevy_shader_utils::simplex_noise_2d
    #import bevy_pbr::utils

    struct CustomMaterial {
    time: f32,
    // color: vec4<f32>,
    // base_color: vec4<f32>;
    // emissive: vec4<f32>;
    // perceptual_roughness: f32;
    // metallic: f32;
    // reflectance: f32;
    // // 'flags' is a bit field indicating various options. u32 is 32 bits so we have up to 32 options.
    // flags: u32;
    // alpha_cutoff: f32;
    };

    @group(1) @binding(0)
    var<uniform> material: CustomMaterial;

    // @group(1) @binding(3)
    // var base_color_texture: texture_2d<f32>;
    // @group(1) @binding(4)
    // var base_color_sampler: sampler;

    struct Vertex {
    @location(0) position: vec3<f32>,
    @location(1) normal: vec3<f32>,
    #ifdef VERTEX_UVS
    @location(2) uv: vec2<f32>,
    #endif
    #ifdef VERTEX_TANGENTS
    @location(3) tangent: vec4<f32>,
    #endif
    #ifdef VERTEX_COLORS
    @location(4) color: vec4<f32>,
    #endif
    #ifdef SKINNED
    @location(5) joint_indices: vec4<u32>,
    @location(6) joint_weights: vec4<f32>,
    #endif
    };

    struct VertexOutput {
    @builtin(position) clip_position: vec4<f32>,
    @location(0) world_position: vec4<f32>,
    @location(1) world_normal: vec3<f32>,
    #ifdef VERTEX_UVS
    @location(2) uv: vec2<f32>,
    #endif
    #ifdef VERTEX_TANGENTS
    @location(3) world_tangent: vec4<f32>,
    #endif
    #ifdef VERTEX_COLORS
    @location(4) color: vec4<f32>,
    #endif
    };

    @vertex
    fn vertex(vertex: Vertex) -> VertexOutput {

    let thickness = 5.0;
    // higher is shorter
    let how_long_to_stay_in_opposite_state = 30.0;
    let frequency = 2.0;
    // let position_diff = pow(sin(2.0 * material.time), 1.0);
    let position_diff = 1.0 - pow(thickness * sin(frequency * material.time + vertex.position.y + vertex.position.z), how_long_to_stay_in_opposite_state);

    // let smooth_diff = smoothstep(0.0, 1.0, position_diff);
    let position = (vertex.normal * (smoothstep(0.0, 1.0, position_diff)) * 0.02) + vertex.position;

    var out: VertexOutput;
    #ifdef SKINNED
    var model = skin_model(vertex.joint_indices, vertex.joint_weights);
    out.world_normal = skin_normals(model, vertex.normal);
    #else
    var model = mesh.model;
    out.world_normal = mesh_normal_local_to_world(vertex.normal);
    #endif
    // out.world_position = mesh_position_local_to_world(model, vec4<f32>(vertex.position, 1.0));
    out.world_position = mesh_position_local_to_world(model, vec4<f32>(position, 1.0));
    #ifdef VERTEX_UVS
    out.uv = vertex.uv;
    #endif
    #ifdef VERTEX_TANGENTS
    out.world_tangent = mesh_tangent_local_to_world(model, vertex.tangent);
    #endif
    #ifdef VERTEX_COLORS
    out.color = vertex.color;
    #endif

    out.clip_position = mesh_position_world_to_clip(out.world_position);

    out.color = out.clip_position;

    // out.view_position = view.inverse_view * out.world_position;
    // out.view_position = view.inverse_view_proj * out.clip_position;
    return out;
    }
  7. Kielan revised this gist Nov 26, 2025. 1 changed file with 15 additions and 2 deletions.
    17 changes: 15 additions & 2 deletions main.rs
    View file
    Original file line number Diff line number Diff line change
    @@ -103,6 +103,13 @@ commands.spawn_bundle(Camera3dBundle {
    #import bevy_pbr::mesh_view_bindings
    #import bevy_pbr::mesh_bindings

    #import bevy_pbr::pbr_types
    #import bevy_pbr::utils
    #import bevy_pbr::clustered_forward
    #import bevy_pbr::lighting
    #import bevy_pbr::shadows
    #import bevy_pbr::pbr_functions

    @group(1) @binding(0)
    var texture: texture_2d<f32>;
    @group(1) @binding(1)
    @@ -120,6 +127,11 @@ fn dir_to_requirerectangular(dir: vec3<f32>) -> vec2<f32> {
    return vec2<f32>(x. y);
    }

    fn refract(I: vec3<f32>, N: vec3<f32>, eta: f32) -> vec3<f32> {
    let k = max((1.0 - eta * eta * (1.0 - dot(N, I) * dot(N, I)))), 0.0);
    return eta * I - (eta * dot(N, I) + sqrt(k)) * N;
    }

    @fragment
    fn fragment(in:FragmentInput) -> @location(0) vec4<f32> {
    var N = normalize(in.world_normal);
    @@ -132,10 +144,11 @@ fn fragment(in:FragmentInput) -> @location(0) vec4<f32> {
    col = mix(col, vec3(0.5, 0.1, 0.0), glow);

    var reflect_coords = dir_to_reqire_rectangular(reflect(-V, N));
    let reflection = textureSample(texture, texture_sampler, reflect_coords).rgs;
    let reflection = textureSample(texture, texture_sampler, reflect_coords).rgb;

    //return vec4(0.0, 1.0, 0.0, 1.0);
    //return vec4(vec3(glow), 1.0);
    //return vec4(col, 1.0);
    return vec4(reflection, 1.0);
    //return vec4(reflection, 1.0);
    return tone_mapping(vec4(reflection, 1.0));
    }
  8. Kielan revised this gist Nov 26, 2025. 1 changed file with 5 additions and 1 deletion.
    6 changes: 5 additions & 1 deletion main.rs
    View file
    Original file line number Diff line number Diff line change
    @@ -131,7 +131,11 @@ fn fragment(in:FragmentInput) -> @location(0) vec4<f32> {

    col = mix(col, vec3(0.5, 0.1, 0.0), glow);

    var reflect_coords = dir_to_reqire_rectangular(reflect(-V, N));
    let reflection = textureSample(texture, texture_sampler, reflect_coords).rgs;

    //return vec4(0.0, 1.0, 0.0, 1.0);
    //return vec4(vec3(glow), 1.0);
    return vec4(col, 1.0);
    //return vec4(col, 1.0);
    return vec4(reflection, 1.0);
    }
  9. Kielan revised this gist Nov 26, 2025. 1 changed file with 7 additions and 1 deletion.
    8 changes: 7 additions & 1 deletion main.rs
    View file
    Original file line number Diff line number Diff line change
    @@ -113,7 +113,13 @@ struct FragmentInput {
    @builtin(position) frag_coord: vec4<f32>,
    #import bevy_pbr::mesh_vertext_output
    };


    fn dir_to_requirerectangular(dir: vec3<f32>) -> vec2<f32> {
    let x = atan2(dir.z, dir.x) / (2.0 * PI) + 0.5 //e-1
    let y = acos(dir.y) / PI; // e-1
    return vec2<f32>(x. y);
    }

    @fragment
    fn fragment(in:FragmentInput) -> @location(0) vec4<f32> {
    var N = normalize(in.world_normal);
  10. Kielan revised this gist Nov 26, 2025. 1 changed file with 7 additions and 2 deletions.
    9 changes: 7 additions & 2 deletions main.rs
    View file
    Original file line number Diff line number Diff line change
    @@ -100,8 +100,13 @@ commands.spawn_bundle(Camera3dBundle {
    });

    //assets/shaders/glow.wgsl
    ##import bevy_pbr::mesh_view_bindings
    ##import bevy_pbr::mesh_bindings
    #import bevy_pbr::mesh_view_bindings
    #import bevy_pbr::mesh_bindings

    @group(1) @binding(0)
    var texture: texture_2d<f32>;
    @group(1) @binding(1)
    var texture_sampler: sampler;

    struct FragmentInput {
    @builtin(front_facing) is_front: bool,
  11. Kielan revised this gist Nov 26, 2025. 1 changed file with 3 additions and 1 deletion.
    4 changes: 3 additions & 1 deletion main.rs
    View file
    Original file line number Diff line number Diff line change
    @@ -32,7 +32,9 @@ fn setup(
    //Load Texture
    let env_texture = asset_server.load("textures_stone_alley_02_1k.hdr");

    let material = glowmaterials.add(GlowMaterial {});
    let material = glowmaterials.add(GlowMaterial {
    env_texture: Some(env_texture),
    });

    //Sphere
    commands.spawn().insert_bundle(MaterialMeshBundle {
  12. Kielan revised this gist Nov 26, 2025. 1 changed file with 24 additions and 0 deletions.
    24 changes: 24 additions & 0 deletions main.rs
    View file
    Original file line number Diff line number Diff line change
    @@ -22,6 +22,30 @@ impl Material for GlowMaterial {
    }
    }

    fn setup(
    mut commands: Commands,
    mut meshes: ResMut<Assets<Mesh>>,
    glowmaterials: ResMut<Assets<GlowyMaterial>>,
    mut materials: ResMut<Assets<StandardMaterial>>,
    asset_server: Res<AssetServer>>,
    ) {
    //Load Texture
    let env_texture = asset_server.load("textures_stone_alley_02_1k.hdr");

    let material = glowmaterials.add(GlowMaterial {});

    //Sphere
    commands.spawn().insert_bundle(MaterialMeshBundle {
    mesh: meshes.add(Mesh::from(shape::UVSphere {
    radius: 1.0,
    ..default()
    })),
    material: material.clone(),
    ..default()
    });

    }

    fn main() {
    App::new()
    .add_plugins((DefaultPlugins.set(plugin: AssetPlugin {
  13. Kielan revised this gist Nov 26, 2025. 1 changed file with 14 additions and 0 deletions.
    14 changes: 14 additions & 0 deletions main.rs
    View file
    Original file line number Diff line number Diff line change
    @@ -8,6 +8,20 @@ use map_loader::*;
    bevy::prelude::*;
    use roxmltree::*;

    #derive(AsBindGroup, Debug, Clone, TypeUuid)]
    #[uuid = "717f64fe-6844-4822-8926-e0ed374294c8"]
    pub struct GlowMaterial {
    #[texture(0)]
    #[sampler(1)]
    pub env_texture: Option<Handle<Image>>,
    }

    impl Material for GlowMaterial {
    fn fragment_shader() -> ShaderRef {
    "shaders/glow.wgsl".into()
    }
    }

    fn main() {
    App::new()
    .add_plugins((DefaultPlugins.set(plugin: AssetPlugin {
  14. Kielan revised this gist Nov 26, 2025. 1 changed file with 2 additions and 0 deletions.
    2 changes: 2 additions & 0 deletions main.rs
    View file
    Original file line number Diff line number Diff line change
    @@ -78,6 +78,8 @@ fn fragment(in:FragmentInput) -> @location(0) vec4<f32> {

    var col = vec3(0.0, 0.0, 0.0);

    col = mix(col, vec3(0.5, 0.1, 0.0), glow);

    //return vec4(0.0, 1.0, 0.0, 1.0);
    //return vec4(vec3(glow), 1.0);
    return vec4(col, 1.0);
  15. Kielan revised this gist Nov 26, 2025. 1 changed file with 4 additions and 1 deletion.
    5 changes: 4 additions & 1 deletion main.rs
    View file
    Original file line number Diff line number Diff line change
    @@ -76,6 +76,9 @@ fn fragment(in:FragmentInput) -> @location(0) vec4<f32> {
    let NdotV = max(dot(N, V), 0.0001);
    let glow = pow(NdotV, 2.0);

    var col = vec3(0.0, 0.0, 0.0);

    //return vec4(0.0, 1.0, 0.0, 1.0);
    return vec4(vec3(glow), 1.0);
    //return vec4(vec3(glow), 1.0);
    return vec4(col, 1.0);
    }
  16. Kielan revised this gist Nov 26, 2025. 1 changed file with 4 additions and 1 deletion.
    5 changes: 4 additions & 1 deletion main.rs
    View file
    Original file line number Diff line number Diff line change
    @@ -73,6 +73,9 @@ struct FragmentInput {
    fn fragment(in:FragmentInput) -> @location(0) vec4<f32> {
    var N = normalize(in.world_normal);
    var V = normalize(view.world_positin.xyz - in.world_position.xyz);
    let NdotV = max(dot(N, V), 0.0001);
    let glow = pow(NdotV, 2.0);

    return vec4(0.0, 1.0, 0.0, 1.0);
    //return vec4(0.0, 1.0, 0.0, 1.0);
    return vec4(vec3(glow), 1.0);
    }
  17. Kielan revised this gist Nov 26, 2025. 1 changed file with 3 additions and 1 deletion.
    4 changes: 3 additions & 1 deletion main.rs
    View file
    Original file line number Diff line number Diff line change
    @@ -70,7 +70,9 @@ struct FragmentInput {
    };

    @fragment
    fn fragmentfragment(in:FragmentInput) -> location(0) vec4<f32> {
    fn fragment(in:FragmentInput) -> @location(0) vec4<f32> {
    var N = normalize(in.world_normal);
    var V = normalize(view.world_positin.xyz - in.world_position.xyz);

    return vec4(0.0, 1.0, 0.0, 1.0);
    }
  18. Kielan revised this gist Nov 26, 2025. 1 changed file with 17 additions and 1 deletion.
    18 changes: 17 additions & 1 deletion main.rs
    View file
    Original file line number Diff line number Diff line change
    @@ -57,4 +57,20 @@ commands.spawn().insert_bundle(MaterialMeshBundle {
    commands.spawn_bundle(Camera3dBundle {
    transform: Transform::from_xyz(5.0, 2.0, 5.0)
    .looking_at(Vec::new(0.0, 0.0, 0.0), Vec3::v),
    });
    });

    //assets/shaders/glow.wgsl
    ##import bevy_pbr::mesh_view_bindings
    ##import bevy_pbr::mesh_bindings

    struct FragmentInput {
    @builtin(front_facing) is_front: bool,
    @builtin(position) frag_coord: vec4<f32>,
    #import bevy_pbr::mesh_vertext_output
    };

    @fragment
    fn fragmentfragment(in:FragmentInput) -> location(0) vec4<f32> {
    var N = normalize(in.world_normal);
    return vec4(0.0, 1.0, 0.0, 1.0);
    }
  19. Kielan created this gist Nov 26, 2025.
    60 changes: 60 additions & 0 deletions main.rs
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,60 @@
    //https://github.com/bevyengine/bevy/blob/latest/examples/asset/processing/asset_processing.rs
    //https://www.youtube.com/watch?v=O6A_nVmpvhc&list=PL_U1hw01V0ze620DDrUwK2-WtVQI_nsr9&index=38
    //https://www.youtube.com/watch?v=i4zImwo_flw&t=5s

    mod map_loader;

    use map_loader::*;
    bevy::prelude::*;
    use roxmltree::*;

    fn main() {
    App::new()
    .add_plugins((DefaultPlugins.set(plugin: AssetPlugin {
    mode: Asset<pde::Unprocessed,
    file_path: "res".to_string(),
    ...Default::default()
    }), MapLoaderPlugin)) &mut App
    .add_systems(schedule: Startup, systems: setup) &mut App
    .add_systems(shedule: Update, systems: hello_assets) &mut App
    .run();
    }

    #[derive(Resource)]
    struct MapHandles {
    maps: Vec<Handle<Map>>
    }

    fn setup(mut commands: Commands, assets: Res<AssetServer>) {
    commands.insert_resource(MapHandles {
    maps: vec![assets.load("maps/tutorials/0.tmx")]
    });
    }

    fn hellow_assets(
    map_handles: Res<MapHandles>,
    map_assets: Res<Assets<Map>>
    ) {
    match map_assets.get(id: &map_handles.maps[0]) {
    Some(file_data: &Map) -> {
    let doc: Document = Document::parse(text: &file_data.0).expect(msg: "can't parse document");
    let elem: Node = doc.descendants().find(|n: &Node| n.tag_name() == "data".into()).expect(msg: "can't find data");
    }
    }
    }

    impl Plugin for MapLoaderPlugin {

    }

    commands.spawn().insert_bundle(MaterialMeshBundle {
    mesh: meshes.add(Mesh::from(shape::UVSphere {
    radius: 1.0,
    ...default()
    }
    });

    commands.spawn_bundle(Camera3dBundle {
    transform: Transform::from_xyz(5.0, 2.0, 5.0)
    .looking_at(Vec::new(0.0, 0.0, 0.0), Vec3::v),
    });