diff --git a/Cargo.lock b/Cargo.lock
index 1879459..9b53100 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -747,6 +747,8 @@ dependencies = [
  "bevy_text",
  "bevy_time",
  "bevy_transform",
+ "bevy_ui",
+ "bevy_ui_render",
  "bevy_utils",
  "bevy_window",
  "bevy_winit",
@@ -1223,6 +1225,68 @@ dependencies = [
  "thiserror 2.0.17",
 ]
 
+[[package]]
+name = "bevy_ui"
+version = "0.17.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "aa0fe27b8c641c2537480774dfd9198d56779371b04dd76618db39da4e7c7483"
+dependencies = [
+ "accesskit",
+ "bevy_a11y",
+ "bevy_app",
+ "bevy_asset",
+ "bevy_camera",
+ "bevy_color",
+ "bevy_derive",
+ "bevy_ecs",
+ "bevy_image",
+ "bevy_input",
+ "bevy_math",
+ "bevy_platform",
+ "bevy_reflect",
+ "bevy_sprite",
+ "bevy_text",
+ "bevy_transform",
+ "bevy_utils",
+ "bevy_window",
+ "derive_more",
+ "smallvec",
+ "taffy",
+ "thiserror 2.0.17",
+ "tracing",
+]
+
+[[package]]
+name = "bevy_ui_render"
+version = "0.17.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d1d2e783bb5f0b748e6360a0055421d5c934b43830b205a84996a75e54330cd7"
+dependencies = [
+ "bevy_app",
+ "bevy_asset",
+ "bevy_camera",
+ "bevy_color",
+ "bevy_core_pipeline",
+ "bevy_derive",
+ "bevy_ecs",
+ "bevy_image",
+ "bevy_math",
+ "bevy_mesh",
+ "bevy_platform",
+ "bevy_reflect",
+ "bevy_render",
+ "bevy_shader",
+ "bevy_sprite",
+ "bevy_sprite_render",
+ "bevy_text",
+ "bevy_transform",
+ "bevy_ui",
+ "bevy_utils",
+ "bytemuck",
+ "derive_more",
+ "tracing",
+]
+
 [[package]]
 name = "bevy_utils"
 version = "0.17.3"
@@ -2174,6 +2238,12 @@ dependencies = [
  "bitflags 2.10.0",
 ]
 
+[[package]]
+name = "grid"
+version = "0.15.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "36119f3a540b086b4e436bb2b588cf98a68863470e0e880f4d0842f112a3183a"
+
 [[package]]
 name = "guillotiere"
 version = "0.6.2"
@@ -3649,6 +3719,18 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "taffy"
+version = "0.7.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ab4f4d046dd956a47a7e1a2947083d7ac3e6aa3cfaaead36173ceaa5ab11878c"
+dependencies = [
+ "arrayvec",
+ "grid",
+ "serde",
+ "slotmap",
+]
+
 [[package]]
 name = "termcolor"
 version = "1.4.1"
diff --git a/Cargo.toml b/Cargo.toml
index 9f14753..a1ff4fd 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -17,7 +17,7 @@ all-features = true
 [features]
 dev = ["bevy/dynamic_linking", "bevy/file_watcher", "bevy/embedded_watcher"]
 debug = ["bevy/debug", "bevy_egui", "bevy/bevy_text"]
-fly_camera = []
+fly_camera = ["bevy/bevy_text", "bevy/bevy_ui", "bevy/bevy_ui_render", "bevy/default_font"]
 
 [dependencies]
 bevy = { version = "0.17.3", default-features = false, features = [
diff --git a/src/fly_camera.rs b/src/fly_camera.rs
index 33d45ad..762343f 100644
--- a/src/fly_camera.rs
+++ b/src/fly_camera.rs
@@ -1,10 +1,17 @@
 //! Camera movement logic based on <https://github.com/mcpar-land/bevy_fly_camera>
+//!
+//! See [`KeyBindings`] as to how to use this plugin.
 use bevy::{
     input::mouse::MouseMotion,
     prelude::*,
     window::{CursorGrabMode, CursorOptions, PrimaryWindow},
 };
 
+/// The duration for which the [`SpeedLabel`] is visible, in seconds.
+///
+/// It indicates the current speed value after you pressed `speed_increase` or `speed_decrease`.
+const SPEED_LABEL_VISIBLE_DURATION: f32 = 2.0;
+
 /// A marker component used in queries when you want flycams and not other cameras
 #[derive(Component)]
 pub struct FlyCam;
@@ -12,26 +19,30 @@ pub struct FlyCam;
 /// Configuration for which keyboard keys control which action
 /// Mouse is used for rotating the camera.
 /// Keyboard is used for moving the camera around.
+///
+/// You can press the Space key ([`toggle_grab_cursor`]) to toggle mouse control on/off.
 #[derive(Resource)]
 pub struct KeyBindings {
-    /// The [`KeyCode`] that increases the speed of the movement of the camera.
+    /// The [`KeyCode`] that increases the speed of the movement of the camera
+    /// (default: [`KeyCode::Digit2`]).
     pub speed_increase: KeyCode,
-    /// The [`KeyCode`] that decreases the speed of the movement of the camera.
+    /// The [`KeyCode`] that decreases the speed of the movement of the camera
+    /// (default: [`KeyCode::Digit1`]).
     pub speed_decrease: KeyCode,
-    /// The [`KeyCode`] that moves the camera forward.
+    /// The [`KeyCode`] that moves the camera forward (default: [`KeyCode::KeyW`]).
     pub move_forward: KeyCode,
-    /// The [`KeyCode`] that moves the camera backward.
+    /// The [`KeyCode`] that moves the camera backward (default: [`KeyCode::KeyS`]).
     pub move_backward: KeyCode,
-    /// The [`KeyCode`] that moves the camera left.
+    /// The [`KeyCode`] that moves the camera left (default: [`KeyCode::KeyA`]).
     pub move_left: KeyCode,
-    /// The [`KeyCode`] that moves the camera right.
+    /// The [`KeyCode`] that moves the camera right (default: [`KeyCode::KeyD`]).
     pub move_right: KeyCode,
-    /// The [`KeyCode`] that moves the camera upward.
+    /// The [`KeyCode`] that moves the camera upward (default: [`KeyCode::KeyR`]).
     pub move_ascend: KeyCode,
-    /// The [`KeyCode`] that moves the camera downward.
+    /// The [`KeyCode`] that moves the camera downward (default: [`KeyCode::KeyF`]).
     pub move_descend: KeyCode,
     /// The [`KeyCode`] that toggles between mouse (rotational) and keyboard (translational)
-    /// control.
+    /// control (default: [`KeyCode::Space`]).
     pub toggle_grab_cursor: KeyCode,
 }
 
@@ -44,8 +55,8 @@ impl Default for KeyBindings {
             move_backward: KeyCode::KeyS,
             move_left: KeyCode::KeyA,
             move_right: KeyCode::KeyD,
-            move_ascend: KeyCode::Space,
-            move_descend: KeyCode::ShiftLeft,
+            move_ascend: KeyCode::KeyR,
+            move_descend: KeyCode::KeyF,
             toggle_grab_cursor: KeyCode::Space,
         }
     }
@@ -172,25 +183,83 @@ fn player_look(
 }
 
 fn cursor_grab(
+    mut commands: Commands,
     keys: Res<ButtonInput<KeyCode>>,
     key_bindings: Res<KeyBindings>,
     primary_cursor_options: Single<&mut CursorOptions, With<PrimaryWindow>>,
     settings: Option<ResMut<MovementSettings>>,
+    mut help_text: Query<(Entity, &mut SpeedLabel)>,
 ) {
     if keys.just_pressed(key_bindings.toggle_grab_cursor) {
         toggle_grab_cursor(primary_cursor_options);
     }
 
     if let Some(mut settings) = settings {
+        let mut speed_changed = false;
+
         if keys.just_pressed(key_bindings.speed_increase) {
             settings.speed *= 2.0;
+            speed_changed = true;
         }
         if keys.just_pressed(key_bindings.speed_decrease) {
             settings.speed /= 2.0;
+            speed_changed = true;
+        }
+
+        if speed_changed {
+            if let Some(mut h) = help_text.iter_mut().next() {
+                h.1.time_to_live = SPEED_LABEL_VISIBLE_DURATION;
+            } else {
+                spawn_speed_text_node(&mut commands);
+            }
+        }
+    }
+}
+
+#[derive(Component)]
+struct SpeedLabel {
+    pub time_to_live: f32,
+}
+
+fn animate_text(
+    mut commands: Commands,
+    time: Res<Time>,
+    mut help_text: Single<(Entity, &mut SpeedLabel)>,
+    settings: Option<Res<MovementSettings>>,
+    mut writer: TextUiWriter,
+) {
+    let entity = help_text.0;
+    let animate = &mut help_text.1;
+
+    if let Some(settings) = settings {
+        animate.time_to_live -= time.delta_secs();
+        if animate.time_to_live < 0.0 {
+            animate.time_to_live = 0.0;
+            let mut ent = commands.get_entity(entity).unwrap();
+            ent.despawn();
         }
+
+        *writer.text(entity, 0) = format!("speed: {}", settings.speed);
+        *writer.color(entity, 0) =
+            Color::linear_rgba(1.0, 1.0, 1.0, animate.time_to_live.clamp(0.0, 1.0)).into();
     }
 }
 
+fn spawn_speed_text_node(commands: &mut Commands) {
+    commands.spawn((
+        Text::new(""),
+        SpeedLabel {
+            time_to_live: SPEED_LABEL_VISIBLE_DURATION,
+        },
+        Node {
+            position_type: PositionType::Absolute,
+            left: px(12),
+            top: px(12),
+            ..default()
+        },
+    ));
+}
+
 /// A plugin to control a camera with "fly" keyboard controls
 pub struct FlyCameraPlugin;
 impl Plugin for FlyCameraPlugin {
@@ -198,6 +267,9 @@ impl Plugin for FlyCameraPlugin {
         app.init_resource::<MovementSettings>()
             .init_resource::<RotationSettings>()
             .init_resource::<KeyBindings>()
-            .add_systems(Update, (player_look, cursor_grab, player_move));
+            .add_systems(
+                Update,
+                (player_look, cursor_grab, player_move, animate_text),
+            );
     }
 }
diff --git a/src/shaders/clouds_compute.wgsl b/src/shaders/clouds_compute.wgsl
index 8509a58..ccd0675 100644
--- a/src/shaders/clouds_compute.wgsl
+++ b/src/shaders/clouds_compute.wgsl
@@ -156,7 +156,6 @@ fn get_ray(ray_origin: vec3f, ray_dir: vec3f, max_dist: f32) -> Ray {
     var inside = intersect_planet_sphere(ray_dir, ray_origin.y - config.planet_radius);
 
     if (start <= inside && inside <= end) {
-        return Ray(0.0, 0.0, 0.0);
         if (ray_dir.y < 0.0) {
             end = inside;
         } else {