Remove unused material (bevyengine#1898)

This doesn't do anything and complicates the example.

Author: cart

examples/shader/mesh_custom_attribute.rs

@@ -1,11 +1,8 @@
 use bevy::{
     prelude::*,
-    reflect::TypeUuid,
     render::{
         mesh::{shape, VertexAttributeValues},
         pipeline::{PipelineDescriptor, RenderPipeline},
-        render_graph::{base, AssetRenderResourcesNode, RenderGraph},
-        renderer::RenderResources,
         shader::{ShaderStage, ShaderStages},
     },
 };
@@ -14,15 +11,10 @@ use bevy::{
 fn main() {
     App::build()
         .add_plugins(DefaultPlugins)
-        .add_asset::<MyMaterialWithVertexColorSupport>()
         .add_startup_system(setup.system())
         .run();
 }
 
-#[derive(RenderResources, Default, TypeUuid)]
-#[uuid = "0320b9b8-b3a3-4baa-8bfa-c94008177b17"]
-struct MyMaterialWithVertexColorSupport;
-
 const VERTEX_SHADER: &str = r#"
 #version 450
 layout(location = 0) in vec3 Vertex_Position;
@@ -56,34 +48,13 @@ fn setup(
     mut pipelines: ResMut<Assets<PipelineDescriptor>>,
     mut shaders: ResMut<Assets<Shader>>,
     mut meshes: ResMut<Assets<Mesh>>,
-    mut materials: ResMut<Assets<MyMaterialWithVertexColorSupport>>,
-    mut render_graph: ResMut<RenderGraph>,
 ) {
     // Create a new shader pipeline
     let pipeline_handle = pipelines.add(PipelineDescriptor::default_config(ShaderStages {
         vertex: shaders.add(Shader::from_glsl(ShaderStage::Vertex, VERTEX_SHADER)),
         fragment: Some(shaders.add(Shader::from_glsl(ShaderStage::Fragment, FRAGMENT_SHADER))),
     }));
 
-    // Add an AssetRenderResourcesNode to our Render Graph. This will bind
-    // MyMaterialWithVertexColorSupport resources to our shader
-    render_graph.add_system_node(
-        "my_material_with_vertex_color_support",
-        AssetRenderResourcesNode::<MyMaterialWithVertexColorSupport>::new(true),
-    );
-
-    // Add a Render Graph edge connecting our new "my_material" node to the main pass node. This
-    // ensures "my_material" runs before the main pass
-    render_graph
-        .add_node_edge(
-            "my_material_with_vertex_color_support",
-            base::node::MAIN_PASS,
-        )
-        .unwrap();
-
-    // Create a new material
-    let material = materials.add(MyMaterialWithVertexColorSupport {});
-
     // create a generic cube
     let mut cube_with_vertex_colors = Mesh::from(shape::Cube { size: 2.0 });
 
@@ -128,16 +99,14 @@ fn setup(
         ]),
     );
     // cube
-    commands
-        .spawn_bundle(MeshBundle {
-            mesh: meshes.add(cube_with_vertex_colors), // use our cube with vertex colors
-            render_pipelines: RenderPipelines::from_pipelines(vec![RenderPipeline::new(
-                pipeline_handle,
-            )]),
-            transform: Transform::from_xyz(0.0, 0.0, 0.0),
-            ..Default::default()
-        })
-        .insert(material);
+    commands.spawn_bundle(MeshBundle {
+        mesh: meshes.add(cube_with_vertex_colors), // use our cube with vertex colors
+        render_pipelines: RenderPipelines::from_pipelines(vec![RenderPipeline::new(
+            pipeline_handle,
+        )]),
+        transform: Transform::from_xyz(0.0, 0.0, 0.0),
+        ..Default::default()
+    });
     // camera
     commands.spawn_bundle(PerspectiveCameraBundle {
         transform: Transform::from_xyz(3.0, 5.0, -8.0).looking_at(Vec3::ZERO, Vec3::Y),