WIP Blendshapes (#45)

* WIP Blendshapes

* Greatly overhauled how code works

* Stripped almost everything out and simplified code

---------

Co-authored-by: Ryan Butler <[email protected]>

.gitignore

@@ -4,3 +4,4 @@
 .idea
 .envrc
 .direnv
+.vscode

Cargo.toml

@@ -8,6 +8,7 @@ members = [
 	"skills/openxr-6dof",
 	"skills/xr-ik-mirror",
 	"skills/entity-inspector",
+	"skills/blendshapes",
 ]
 
 # These settings will apply to all members of the workspace that opt in to them

skills/blendshapes/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "blendshapes"
+version.workspace = true
+license.workspace = true
+repository.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+
+[dependencies]
+bevy.workspace = true

skills/blendshapes/README.md

@@ -0,0 +1,9 @@
+# Blendshapes and Morph Targets
+
+Demonstrates how to use morph targets to animate the blend shapes. For example
+to make a gltf avatar blink.
+
+To run the code:
+```bash
+cargo run -p blendshapes
+```

skills/blendshapes/src/main.rs

@@ -0,0 +1,64 @@
+use bevy::prelude::*;
+
+/// The blendshape/morph target corresponding to a blink is at this index
+const BLINK_MORPH_IDX: usize = 13;
+const FACE_ENTITY_NAME: &str = "Face";
+const ASSET_FOLDER: &str = concat!(env!("CARGO_MANIFEST_DIR"), "/../../assets/");
+
+fn main() {
+	// This will take like 5 seconds to load the gltf/vrm model, don't worry, just wait.
+	App::new()
+		.insert_resource(AmbientLight {
+			color: Color::WHITE,
+			brightness: 1.0 / 5.0f32,
+		})
+		.add_plugins(DefaultPlugins.set(AssetPlugin {
+			file_path: ASSET_FOLDER.to_string(),
+			..default()
+		}))
+		.add_systems(Startup, setup)
+		.add_systems(Update, animate_blink)
+		.run()
+}
+
+fn setup(mut commands: Commands, assets: Res<AssetServer>) {
+	commands
+		.spawn(SpatialBundle::default())
+		.with_children(|parent| {
+			parent.spawn(Camera3dBundle {
+				transform: Transform::from_xyz(0.0, 1.45, 0.5)
+					.looking_at(Vec3::new(0.0, 1.45, 0.0), Vec3::Y),
+				projection: bevy::render::camera::Projection::Perspective(
+					PerspectiveProjection {
+						fov: std::f32::consts::FRAC_PI_4,
+						aspect_ratio: 1.0,
+						near: 0.1,
+						far: 100.0,
+					},
+				),
+				..default()
+			});
+		});
+
+	commands.spawn(SceneBundle {
+		scene: assets.load("malek.gltf#Scene0"),
+		transform: Transform::from_xyz(0.0, 0.0, 0.0).with_rotation(Quat::from_euler(
+			EulerRot::XYZ,
+			0.0,
+			180.0_f32.to_radians(),
+			0.0,
+		)),
+		..default()
+	});
+}
+
+fn animate_blink(mut morphs: Query<(&Name, &mut MorphWeights)>, time: Res<Time>) {
+	let Some((_, mut weights)) = morphs
+		.iter_mut()
+		.find(|(name, _)| name.as_str() == FACE_ENTITY_NAME)
+	else {
+		return;
+	};
+	weights.weights_mut()[BLINK_MORPH_IDX] =
+		(f32::sin(time.elapsed_seconds() * 10.0) + 1.) / 2.;
+}