land-vertex exploration

land_vertex_shader.wgsl

#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

struct StandardMaterial {
    time: 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: StandardMaterial;

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 {
    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));
#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


    var noise = simplexNoise3(vertex.position);

    // out.color = vec4<f32>(vertex.position.x, noise, vertex.position.z, 1.0);
    out.color = vec4<f32>(vertex.uv.x, noise, vertex.uv.y, 1.0);

    out.world_position = mesh_position_local_to_world(model, vec4<f32>(vertex.position.x, noise, vertex.position.z, 1.0));
    // out.world_position.x = -100.0;

    out.clip_position = mesh_position_world_to_clip(out.world_position);


    return out;
}

main.rs

//! Loads and renders a glTF file as a scene.

use bevy::{
    pbr::wireframe::{
        Wireframe, WireframeConfig, WireframePlugin,
    },
    prelude::*,
    reflect::TypeUuid,
    render::{
        mesh::{
            Indices, PrimitiveTopology,
            VertexAttributeValues,
        },
        render_resource::{AsBindGroup, ShaderRef},
    },
    render::{
        render_resource::WgpuFeatures,
        settings::WgpuSettings,
    },
};
use bevy_shader_utils::ShaderUtilsPlugin;
use itertools::Itertools;

fn main() {
    App::new()
        .insert_resource(AmbientLight {
            color: Color::WHITE,
            brightness: 1.0 / 5.0f32,
        })
        .insert_resource(ClearColor(
            Color::hex("071f3c").unwrap(),
        ))
        .insert_resource(WgpuSettings {
            features: WgpuFeatures::POLYGON_MODE_LINE,
            ..default()
        })
        .add_plugins(DefaultPlugins)
        .add_plugin(WireframePlugin)
        .add_plugin(ShaderUtilsPlugin)
        .add_plugin(
            MaterialPlugin::<LandMaterial>::default(),
        )
        .add_startup_system(setup)
        .add_system(animate_light_direction)
        .add_system(movement)
        .run();
}

fn setup(
    mut commands: Commands,
    mut meshes: ResMut<Assets<Mesh>>,
    mut materials: ResMut<Assets<LandMaterial>>,
    mut standard_materials: ResMut<
        Assets<StandardMaterial>,
    >,
    asset_server: Res<AssetServer>,
) {
    commands
        .spawn_bundle(Camera3dBundle {
            transform: Transform::from_xyz(0.0, 1.5, 10.0)
                .looking_at(
                    Vec3::new(0.0, 0.3, 0.0),
                    Vec3::Y,
                ),
            ..default()
        })
        .insert(Movable);

    const HALF_SIZE: f32 = 1.0;
    commands.spawn_bundle(DirectionalLightBundle {
        directional_light: DirectionalLight {
            shadow_projection: OrthographicProjection {
                left: -HALF_SIZE,
                right: HALF_SIZE,
                bottom: -HALF_SIZE,
                top: HALF_SIZE,
                near: -10.0 * HALF_SIZE,
                far: 10.0 * HALF_SIZE,
                ..default()
            },
            shadows_enabled: true,
            ..default()
        },
        ..default()
    });

    // land
    let mut land = Mesh::from(Land {
        size: 1000.0,
        num_vertices: 1000,
    });
    if let Some(VertexAttributeValues::Float32x3(
        positions,
    )) = land.attribute(Mesh::ATTRIBUTE_POSITION)
    {
        let colors: Vec<[f32; 4]> = positions
            .iter()
            .map(|[r, g, b]| {
                [
                    (1. - *r) / 2.,
                    (1. - *g) / 2.,
                    (1. - *b) / 2.,
                    1.,
                ]
            })
            .collect();
        land.insert_attribute(
            Mesh::ATTRIBUTE_COLOR,
            colors,
        );
    }

    commands
        .spawn()
        .insert_bundle(MaterialMeshBundle {
            mesh: meshes.add(land),
            transform: Transform::from_xyz(0.0, 0.5, 0.0),
            material: materials.add(LandMaterial {
                time: 0.,
                alpha_mode: AlphaMode::Blend,
            }),
            // material: standard_materials.add(
            //     StandardMaterial {
            //         base_color: Color::WHITE,
            //         ..default()
            //     },
            // ),
            ..default()
        })
        .insert(Wireframe);

    // ship
    commands.spawn().insert_bundle(MaterialMeshBundle {
        mesh: meshes
            .add(Mesh::from(shape::Cube { size: 1.0 })),
        transform: Transform::from_xyz(0.0, 1.5, 0.0),
        material: standard_materials.add(
            StandardMaterial {
                base_color: Color::BLUE,
                ..default()
            },
        ),
        ..default()
    });
    // commands.spawn_bundle(SceneBundle {
    //     scene: asset_server
    //         .load("craft/craft_racer.glb#Scene0"),
    //     // scene: asset_server
    //     //     .load("racecar/raceCarGreen.glb/#Scene0"),
    //     ..default()
    // });
    // let my_gltf =
    //     asset_server.load("craft/craft_racer.glb#Scene0");
}

fn animate_light_direction(
    time: Res<Time>,
    mut query: Query<
        &mut Transform,
        With<DirectionalLight>,
    >,
) {
    for mut transform in &mut query {
        transform.rotation = Quat::from_euler(
            EulerRot::ZYX,
            0.0,
            time.seconds_since_startup() as f32
                * std::f32::consts::TAU
                / 10.0,
            -std::f32::consts::FRAC_PI_4,
        );
    }
}

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

/// The Material trait is very configurable, but comes with sensible defaults for all methods.
/// You only need to implement functions for features that need non-default behavior. See the Material api docs for details!
impl Material for LandMaterial {
    // fn fragment_shader() -> ShaderRef {
    //     "shaders/custom_material.wgsl".into()
    // }
    fn vertex_shader() -> ShaderRef {
        "shaders/land_vertex_shader.wgsl".into()
    }

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

// This is the struct that will be passed to your shader
#[derive(AsBindGroup, TypeUuid, Debug, Clone)]
#[uuid = "f690fdae-d598-45ab-8225-97e2a3f056e0"]
pub struct LandMaterial {
    #[uniform(0)]
    time: f32,
    alpha_mode: AlphaMode,
}

#[derive(Debug, Copy, Clone)]
struct Land {
    size: f32,
    num_vertices: u32,
}

impl From<Land> for Mesh {
    fn from(plane: Land) -> Self {
        let extent = plane.size / 2.0;

        let jump = extent / plane.num_vertices as f32;

        let vertices = (0..=plane.num_vertices)
            .cartesian_product(0..=plane.num_vertices)
            .map(|(x, y)| {
                (
                    [
                        x as f32 * jump - 0.5 * extent,
                        0.0,
                        y as f32 * jump - 0.5 * extent,
                    ],
                    [0.0, 1.0, 0.0],
                    [
                        x as f32
                            / plane.num_vertices as f32,
                        y as f32
                            / plane.num_vertices as f32,
                    ],
                )
            })
            .collect::<Vec<_>>();
        // let vertices = [
        //     (
        //         [extent, 0.0, -extent],
        //         [0.0, 1.0, 0.0],
        //         [1.0, 1.0],
        //     ),
        //     (
        //         [extent, 0.0, extent],
        //         [0.0, 1.0, 0.0],
        //         [1.0, 0.0],
        //     ),
        //     (
        //         [-extent, 0.0, extent],
        //         [0.0, 1.0, 0.0],
        //         [0.0, 0.0],
        //     ),
        //     (
        //         [-extent, 0.0, -extent],
        //         [0.0, 1.0, 0.0],
        //         [0.0, 1.0],
        //     ),
        // ];

        // let indices = Indices::U32(vec![0, 2, 1, 0, 3, 2]);
        let indices = Indices::U32(
            (0..=plane.num_vertices)
                .cartesian_product(0..=plane.num_vertices)
                .enumerate()
                .filter_map(|(index, (x, y))| {
                    if y >= plane.num_vertices {
                        None
                    } else if x >= plane.num_vertices {
                        None
                    } else {
                        Some([
                            [
                                index as u32,
                                index as u32 + 1,
                                index as u32
                                    + 1
                                    + plane.num_vertices,
                            ],
                            [
                                index as u32,
                                index as u32
                                    + plane.num_vertices
                                    + 1,
                                index as u32
                                    + plane.num_vertices,
                            ],
                        ])
                    }
                })
                .flatten()
                .flatten()
                .collect::<Vec<_>>(),
        );
        dbg!(&indices.iter().take(6).collect::<Vec<_>>());

        let positions: Vec<_> =
            vertices.iter().map(|(p, _, _)| *p).collect();
        let normals: Vec<_> =
            vertices.iter().map(|(_, n, _)| *n).collect();
        let uvs: Vec<_> =
            vertices.iter().map(|(_, _, uv)| *uv).collect();

        let mut mesh =
            Mesh::new(PrimitiveTopology::TriangleList);
        mesh.set_indices(Some(indices));
        mesh.insert_attribute(
            Mesh::ATTRIBUTE_POSITION,
            positions,
        );
        mesh.insert_attribute(
            Mesh::ATTRIBUTE_NORMAL,
            normals,
        );
        mesh.insert_attribute(Mesh::ATTRIBUTE_UV_0, uvs);
        mesh
    }
}

#[derive(Component)]
struct Movable;
fn movement(
    input: Res<Input<KeyCode>>,
    time: Res<Time>,
    mut query: Query<&mut Transform, With<Movable>>,
) {
    for mut transform in query.iter_mut() {
        let mut direction = Vec3::ZERO;
        if input.pressed(KeyCode::Up) {
            direction.z += 1.0;
        }
        if input.pressed(KeyCode::Down) {
            direction.z -= 1.0;
        }
        if input.pressed(KeyCode::Left) {
            direction.x -= 1.0;
        }
        if input.pressed(KeyCode::Right) {
            direction.x += 1.0;
        }

        transform.translation +=
            time.delta_seconds() * 2.0 * direction;
    }
}