HD smoke trails as smooth ribbons (fork patch 30)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Clouds occlude by depth, world-anchored noise, visual-only replay time (fork patch 29; #67 , #68 , #70 )
2026-10-30 03:44:45 +03:00 · 2026-10-30 03:26:10 +03:00
31 changed files with 694 additions and 28 deletions
@@ -118,6 +118,7 @@ Bind groups кэшируются и пересоздаются только пр
 | 15 | текстура неба (`sky_lut`) |
 | 16, 17 | объёмный туман (свет+пропускание) и длина его луча |
 | 18, 19 | объёмные облака, карта теней облаков |
+| 20 | длина луча каждого текселя облаков (`cloud_dist_tex`, для апсэмплинга по глубине) |

 `HdFrame` (Rust и WGSL держать в синхроне!): `inverse_view_proj`, `resolution` (w, h, 1/w, 1/h), `params` (число
 источников, экспозиция, bloom, счётчик кадров), `cascades[2]`, `sun` (направление, сила), `sun_color` (rgb, ночь),
@@ -227,6 +228,9 @@ HORIZON_HD_TAA=0 --out run-home-bench/out/taa-off` — A/B; `--baseline run-home

 | Материалы и блики (план 5): G-буфер `levels.zw` = шероховатость, металличность; GGX-блик солнца с Френелем и отражение неба (`sky_along`/`atmosphere_sky`) в `shade_surface`; мокрые поверхности и лужи в дождь (`HdFrame.surface`); `HORIZON_HD_SPECULAR=0` — выкл. | готово | в рабочем дереве форка |
 | Ветер (план 7): листва и растения качаются в вершинной стадии террейна (`Globals.hd_wind`, `hd_materials`), те же смещения в тенях; `HORIZON_HD_WIND=0` — выкл. | готово | в рабочем дереве форка |
+| #67: облака марш идут до ближайшей поверхности (`fs_cloud` читает глубину мира, вторая цель — длина луча, история отбрасывается при другой длине); `fs_light` кладёт облака на все пиксели (`cloud_at`: 4 текселя с весом по близости длины луча), под туман и над поверхностью, для воды — в `air`; луч внутри слоя вдоль горизонта больше не пропускается | готово; проверено только пустой полигон (нет гор/техники в слое, снимки `scratchpad/c*.png`), бюджет GPU на Mac не мерился | в рабочем дереве форка |
+| #68: шум облаков по Y — от низа слоя, а не от камеры; шкалы тумана 170→128, дыма 22→32, луж 0.45/1.3→0.5/1.25 делят период обёртки 65536/256; тест `noise_scales_divide_the_camera_wrap` | готово | в рабочем дереве форка |
+| #70: `Game::sky_darken` — всегда реальное время мира (ИИ, спавн, блоки, статистика); `shown_sky_darken` (время реплея) — только тени сущностей и свет глаза; небо/луна/цвета остаются по показанному времени | готово (собрано, игровой проверки день/ночь реплея нет) | в рабочем дереве форка |
 | Объёмный дым и следы ракет (#54, п. 8 плана): API уровня 14 `render.set-smoke`, сетка дыма 128×64×128 по 3 блока (`gfx/hd/smoke.rs`, `smoke_grid.wgsl`), марш в проходе тумана, «туннель» в тумане и облаках, `HORIZON_HD_SMOKE=0`; мод: `airdef-mod/src/smoke.rs` (следы дронов и ракет, колонны над пожарами, дым взрывов) | готово, в рабочем дереве форка; вид не настраивался (см. «Дым и следы») | не закоммичено |

 ## План (по порядку) и ТЗ
@@ -1,7 +1,7 @@
 From 3de7a6875140a107e28563cc44489b55f5794517 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Wed, 28 Oct 2026 12:37:45 +0300
-Subject: [PATCH 01/28] Mod API (AirDef fork): world models, client particles,
+Subject: [PATCH 01/30] Mod API (AirDef fork): world models, client particles,
 sounds, ground heights

 render.set-models draws block models with an interpolated pose per id;
@@ -1,7 +1,7 @@
 From a6d64e6415bf618539af464e521091e72b72d72f Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Wed, 28 Oct 2026 12:39:45 +0300
-Subject: [PATCH 02/28] cargo-horizon-mod: report particles and sounds
+Subject: [PATCH 02/30] cargo-horizon-mod: report particles and sounds

 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
 ---
@@ -1,7 +1,7 @@
 From ee79b3562feebe51959a01f1585a9e85bd53ccb5 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Wed, 28 Oct 2026 13:33:10 +0300
-Subject: [PATCH 03/28] Mod API (AirDef fork): full-screen post pass for mods
+Subject: [PATCH 03/30] Mod API (AirDef fork): full-screen post pass for mods

 render.set-post compiles a mod's WGSL after a prelude (camera matrices,
 time, 256 vec4 of params, the world's colour and depth) and runs it after
@@ -1,7 +1,7 @@
 From 2b137dbbedd540daeebc7f5e387847aeb56a1355 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Wed, 28 Oct 2026 22:09:30 +0300
-Subject: [PATCH 04/28] Mod models: draw far models as scaled impostors past
+Subject: [PATCH 04/30] Mod models: draw far models as scaled impostors past
 the far plane, cull at 4096

 ---
@@ -1,7 +1,7 @@
 From c8ebca6e0af68630e65211844b34d25c5b985c03 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Wed, 28 Oct 2026 22:31:00 +0300
-Subject: [PATCH 05/28] Mod cameras: render.set-views draws the world from
+Subject: [PATCH 05/30] Mod cameras: render.set-views draws the world from
 other points into pictures that HUD view shapes show (API level 9)

 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
@@ -1,7 +1,7 @@
 From 8d2261fc4f8072c32e454139cfea7a8c0cd9d664 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Wed, 28 Oct 2026 23:08:21 +0300
-Subject: [PATCH 06/28] Mods: more fuel per tick and per event (AirDef plans
+Subject: [PATCH 06/30] Mods: more fuel per tick and per event (AirDef plans
 raids)

 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
@@ -1,7 +1,7 @@
 From 6c548de34def8e4a624d734243418090798bd16a Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Wed, 28 Oct 2026 23:25:29 +0300
-Subject: [PATCH 07/28] Mod cameras up to 1920x1080 (full-screen replays)
+Subject: [PATCH 07/30] Mod cameras up to 1920x1080 (full-screen replays)

 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
 ---
@@ -1,7 +1,7 @@
 From 9b9e93269d67401cc620567a884d5ce97f68d76e Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 11:15:11 +0300
-Subject: [PATCH 08/28] Mod cameras: distant terrain tiles, fog measured from
+Subject: [PATCH 08/30] Mod cameras: distant terrain tiles, fog measured from
 the camera, no impostors while one is shown

 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
@@ -1,7 +1,7 @@
 From 065d9fa02966238a5bd9ff460392a1a809db0b11 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 11:25:45 +0300
-Subject: [PATCH 09/28] Mods: game.world-id, so mods keep state per world (API
+Subject: [PATCH 09/30] Mods: game.world-id, so mods keep state per world (API
 level 9)

 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
@@ -1,7 +1,7 @@
 From 1bf28135fd9a31f837323dc3a8d81ed73343d816 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 12:01:08 +0300
-Subject: [PATCH 10/28] cargo-horizon-mod: trial runs behind feature full, so a
+Subject: [PATCH 10/30] cargo-horizon-mod: trial runs behind feature full, so a
 packing-only tool skips wasmtime

 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
@@ -1,7 +1,7 @@
 From 0a56f5616df4699588cbcc529d4720661baa810f Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 13:18:43 +0300
-Subject: [PATCH 11/28] HD lighting: G-buffer pass, per-pixel mod point lights
+Subject: [PATCH 11/30] HD lighting: G-buffer pass, per-pixel mod point lights
 in HDR, bloom and tone curve; render.set-lights and render.set-lighting (API
 level 10)

@@ -1,7 +1,7 @@
 From 9ebf0031fe9ba6b7f02afb26e4fd3a1ba4ddb0d0 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 13:59:43 +0300
-Subject: [PATCH 12/28] HD lighting stage 2: sun and moon shadow cascades, the
+Subject: [PATCH 12/30] HD lighting stage 2: sun and moon shadow cascades, the
 world relit (sun by face angle and shadow, sky and block light through the
 lightmap), light shafts and halos, fog over it again, a light colour grade

@@ -1,7 +1,7 @@
 From 7a5a38f68923aec62f10bfa0df50b436474ed612 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 16:19:53 +0300
-Subject: [PATCH 13/28] HD: bind groups cached until a resize or a new source,
+Subject: [PATCH 13/30] HD: bind groups cached until a resize or a new source,
 shadow passes draw only the entities that cast shadows

 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
@@ -1,7 +1,7 @@
 From 8020811e57d4b5a9ea1cd72d30ce859dc5095d35 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 16:25:44 +0300
-Subject: [PATCH 14/28] HD: lights culled per 16x16 tile (surface and halo
+Subject: [PATCH 14/30] HD: lights culled per 16x16 tile (surface and halo
 lists built on the CPU), a naga test for the lighting shaders

 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
@@ -1,7 +1,7 @@
 From 72d3fddfea329e578162656151350f0aa2efd323 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 16:43:36 +0300
-Subject: [PATCH 15/28] HD: GPU time per pass in the F3 timing list,
+Subject: [PATCH 15/30] HD: GPU time per pass in the F3 timing list,
 half-resolution GTAO with a depth-aware blur

 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
@@ -1,7 +1,7 @@
 From 1fd83a821bf270879d8ece5aa583f200ed920d89 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 17:02:02 +0300
-Subject: [PATCH 16/28] HD: shadows draw only sun-facing quads and skip buried
+Subject: [PATCH 16/30] HD: shadows draw only sun-facing quads and skip buried
 sections, the far cascade every second frame; TAA (Halton jitter,
 reprojection by depth, YCoCg variance clipping) before bloom

@@ -1,7 +1,7 @@
 From 1502d359d599228fe0f44ce6b99a3fded2ac5ea0 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 17:02:02 +0300
-Subject: [PATCH 17/28] Mods: model handles (render.model-id, model-generation,
+Subject: [PATCH 17/30] Mods: model handles (render.model-id, model-generation,
 set-models-by-id; API level 11) so mods send no model names each tick;
 clear-post and set-lighting documented

@@ -1,7 +1,7 @@
 From 0f9d99b8ad3e4b72e621d84c2396cf1d3d2b7a33 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 17:19:57 +0300
-Subject: [PATCH 18/28] HD: temporal upscaling (HORIZON_HD_SCALE: world,
+Subject: [PATCH 18/30] HD: temporal upscaling (HORIZON_HD_SCALE: world,
 G-buffer and lighting at a lower size, rebuilt to the window in the TAA
 pass); fix flickering shadows near the player (the near cascade lost its
 sections on frames the far one was held, the held far matrix ignored the
@@ -1,7 +1,7 @@
 From 38250c4392e27d5700842ca6ee47291dd1831b72 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 17:47:52 +0300
-Subject: [PATCH 19/28] HD water: its own pass (colour, normal, depth), the
+Subject: [PATCH 19/30] HD water: its own pass (colour, normal, depth), the
 floor under it lit, a composite with world-space waves, refraction with depth
 absorption in the biome colour, screen-space reflections, Fresnel and a
 shadowed sun glint (HORIZON_HD_WATER=0 to switch off)
@@ -1,7 +1,7 @@
 From dbc6f8a6e9c2eeabe1de15f1794013c90be7faa5 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 17:56:04 +0300
-Subject: [PATCH 20/28] HD water: no vanilla texture on the surface (the biome
+Subject: [PATCH 20/30] HD water: no vanilla texture on the surface (the biome
 colour only), a darker, deeper colour

 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
@@ -1,7 +1,7 @@
 From 13e74537dd6e63482e3613e0e416de1158944dfe Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 18:38:19 +0300
-Subject: [PATCH 21/28] HD sky and light: a physical atmosphere (Rayleigh, Mie,
+Subject: [PATCH 21/30] HD sky and light: a physical atmosphere (Rayleigh, Mie,
 ozone; constants and transmittance after Photon, MIT) for the sky, haze, fog
 and water reflections; warmer sunlight from the atmosphere's transmittance, a
 gentle sky-coloured ambient, soft PCSS-lite shadows near the player, a haze
@@ -1,7 +1,7 @@
 From 6277e051a89c2537570982f6ef275887193c05cf Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 19:02:16 +0300
-Subject: [PATCH 22/28] HD water: a darker blue, a little clearer, ripples a
+Subject: [PATCH 22/30] HD water: a darker blue, a little clearer, ripples a
 little higher

 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
@@ -1,7 +1,7 @@
 From 982265d21bb9d74ec0040db03feb5a55762286ad Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 21:41:48 +0300
-Subject: [PATCH 23/28] HD: Photon-style sunsets (Rec. 2020 atmosphere, sun
+Subject: [PATCH 23/30] HD: Photon-style sunsets (Rec. 2020 atmosphere, sun
 tint, blue hour; MIT), volumetric clouds with ground shadows instead of
 vanilla's in HD, volumetric fog with sun shafts and morning mist
 (HORIZON_HD_CLOUDS=0, HORIZON_HD_VOLFOG=0)
@@ -1,7 +1,7 @@
 From 24971b3c67d8c87673eb2e0d204cedf8a2f46d1c Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 21:43:22 +0300
-Subject: [PATCH 24/28] Mods: world queries for simulations (render.query-rays,
+Subject: [PATCH 24/30] Mods: world queries for simulations (render.query-rays,
 query-sections, world-changes; API level 12): block-exact rays and section
 occupancy by collision, sight or sound, answered next tick within budgets,
 and a log of changed sections
@@ -1,7 +1,7 @@
 From fdec4960983bdff82f3793460f9a5234f0cd3f49 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 22:56:15 +0300
-Subject: [PATCH 25/28] HD fixes: rain level from the world not from rain
+Subject: [PATCH 25/30] HD fixes: rain level from the world not from rain
 geometry (#41), TAA history on the jittered grid (#38), vanilla cloud tint
 without a depth heuristic (#35), air fog once over water (#37), translucent
 things in front of HD water (#36), cheaper sunrise fan (#39), halos in thick
@@ -1,7 +1,7 @@
 From 21391afb26f49505d6cdaf454a6355cd4e747503 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 23:19:53 +0300
-Subject: [PATCH 26/28] HD split into modules (gfx/hd/: one Rust file and one
+Subject: [PATCH 26/30] HD split into modules (gfx/hd/: one Rust file and one
 WGSL file per pass, a shared prelude), contracts for colour, depth, alpha,
 time and coordinates written down, tests that the frame layout and bindings
 match between Rust and WGSL (#45)
@@ -1,7 +1,7 @@
 From 8d4cadbf8534309ac847d34e229f6d764770475d Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 23:22:19 +0300
-Subject: [PATCH 27/28] HD clouds: noise scales that divide the camera's
+Subject: [PATCH 27/30] HD clouds: noise scales that divide the camera's
 65536-block wrap, so the clouds and their shadows no longer jump at x or z =
 0

@@ -1,7 +1,7 @@
 From 0fb59c782abf269fe555faa3241b31acf41e26d7 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Fri, 30 Oct 2026 03:17:11 +0300
-Subject: [PATCH 28/28] HD: volumetric smoke and missile trails with clear
+Subject: [PATCH 28/30] HD: volumetric smoke and missile trails with clear
 tunnels through fog and cloud (render.set-smoke, API level 14; #54); sun
 speculars by material, wet surfaces and puddles in rain, wind in foliage
 (HORIZON_HD_SPECULAR=0, HORIZON_HD_WIND=0, HORIZON_HD_SMOKE=0); HD shaders
@@ -0,0 +1,603 @@
+From e4bc29da45d0d38244c6eb2ba3ffb9ab853540c0 Mon Sep 17 00:00:00 2001
+From: chexit <chexit@duck.com>
+Date: Fri, 30 Oct 2026 03:26:09 +0300
+Subject: [PATCH 29/30] HD clouds composited by depth so terrain and vehicles
+ inside or behind the layer are hidden and those in front stay in front (#67);
+ world-anchored noise everywhere (cloud detail by height above the layer, fog,
+ smoke and puddle scales dividing the wrap) (#68); the replay's time is visual
+ only, gameplay sky darkening uses the world's time (#70)
+
+Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
+---
+ crates/horizon-client/src/game.rs             |  37 +++--
+ crates/horizon-client/src/game/render_tick.rs |   2 +-
+ crates/horizon-client/src/gfx/hd/cloud.wgsl   |  54 ++++++-
+ .../src/gfx/hd/cloud_common.wgsl              |   3 +-
+ crates/horizon-client/src/gfx/hd/fog.wgsl     |   6 +-
+ crates/horizon-client/src/gfx/hd/light.wgsl   |  42 +++++-
+ crates/horizon-client/src/gfx/hd/lighting.rs  |   4 +-
+ crates/horizon-client/src/gfx/hd/volumes.rs   | 135 +++++++++++++++---
+ 8 files changed, 239 insertions(+), 44 deletions(-)
+
+diff --git a/crates/horizon-client/src/game.rs b/crates/horizon-client/src/game.rs
+index 2130d8d88..f21b3dcdd 100644
+--- a/crates/horizon-client/src/game.rs
+++ b/crates/horizon-client/src/game.rs
+@@ -1838,6 +1838,8 @@ struct Game<'a> {
+     events: events::Events,
+     /// The overworld's last `sky_darken` and its inputs (time, rain, thunder).
+     sky_darken_memo: std::cell::Cell<Option<((i64, u32, u32), i32)>>,
+    /// The same for the time a mod shows (a replay's): render only.
+    shown_darken_memo: std::cell::Cell<Option<((i64, u32, u32), i32)>>,
+     persist: persist::EntityMemory,
+     /// Connected to a server: the world comes from the network (game/remote.rs).
+     remote: Option<remote::Remote>,
+@@ -8020,7 +8022,7 @@ impl Game<'_> {
+             .flatten();
+         if let Some(sprite) = shadow_sprite {
+             let ambient = if self.dim == Dim::Nether { 0.1 } else { 0.0 };
+-            let darken = self.sky_darken();
+            let darken = self.shown_sky_darken();
+             let a = alpha;
+             let lerp = |p: Vec3, q: Vec3| {
+                 glam::DVec3::new(
+@@ -8378,33 +8380,43 @@ impl Game<'_> {
+             .map_or(self.world.day_time, |t| t as i64)
+     }
+ 
+    /// The sky's darkening for the game's rules (mob AI, spawning, block behaviour, stats): always
+    /// the world's real time, never a mod's render-only override.
+     fn sky_darken(&self) -> i32 {
+        self.sky_darken_at(self.world.day_time, &self.sky_darken_memo)
+    }
+
+    /// The sky's darkening as the player sees it (entity shadows, particle light): follows the mod's
+    /// time override, so a replay's night looks dark without touching the rules.
+    fn shown_sky_darken(&self) -> i32 {
+        self.sky_darken_at(self.shown_day_time(), &self.shown_darken_memo)
+    }
+
+    fn sky_darken_at(
+        &self,
+        time: i64,
+        memo: &std::cell::Cell<Option<((i64, u32, u32), i32)>>,
+    ) -> i32 {
+         if self.dim == Dim::Nether {
+             return 11;
+         }
+         if self.dim == Dim::End {
+-            let sky = self
+-                .res
+-                .end_environment()
+-                .sample(self.shown_day_time(), None, None);
+            let sky = self.res.end_environment().sample(time, None, None);
+             return (15.0 - 15.0 * sky.sky_light_level).round() as i32;
+         }
+         let (rain, thunder) = self.world.weather.levels(1.0);
+         // Sampled once per (time, weather): every mob asks each tick.
+-        let key = (self.shown_day_time(), rain.to_bits(), thunder.to_bits());
+-        if let Some((k, darken)) = self.sky_darken_memo.get()
+        let key = (time, rain.to_bits(), thunder.to_bits());
+        if let Some((k, darken)) = memo.get()
+             && k == key
+         {
+             return darken;
+         }
+-        let mut sky = self
+-            .res
+-            .environment()
+-            .sample(self.shown_day_time(), None, None);
+        let mut sky = self.res.environment().sample(time, None, None);
+         horizon_client::environment::apply_weather(&mut sky, rain, thunder);
+         // Level.updateSkyBrightness: darkening from the sky light level.
+         let darken = (15.0 - 15.0 * sky.sky_light_level).round() as i32;
+-        self.sky_darken_memo.set(Some((key, darken)));
+        memo.set(Some((key, darken)));
+         darken
+     }
+     fn mob_hit(&self) -> Option<(usize, f64)> {
+@@ -13954,6 +13966,7 @@ impl<'a> Game<'a> {
+             mods: Default::default(),
+             native_shaders: Default::default(),
+             sky_darken_memo: Default::default(),
+            shown_darken_memo: Default::default(),
+             persist: Default::default(),
+             remote: None,
+             lan: None,
+diff --git a/crates/horizon-client/src/game/render_tick.rs b/crates/horizon-client/src/game/render_tick.rs
+index 6807d7718..9912970a5 100644
+--- a/crates/horizon-client/src/game/render_tick.rs
+++ b/crates/horizon-client/src/game/render_tick.rs
+@@ -241,7 +241,7 @@ impl Game<'_> {
+             eye[2].floor() as i32,
+         ];
+         let packed = self.world.light(b[0], b[1], b[2]);
+-        let sky = i32::from(packed >> 4) - self.sky_darken();
+        let sky = i32::from(packed >> 4) - self.shown_sky_darken();
+         let raw = sky.max(i32::from(packed & 15)).clamp(0, 15) as u8;
+         lightmap_brightness(if self.dim == Dim::Nether { 0.1 } else { 0.0 }, raw)
+     }
+diff --git a/crates/horizon-client/src/gfx/hd/cloud.wgsl b/crates/horizon-client/src/gfx/hd/cloud.wgsl
+index fad234a46..39a239f4d 100644
+--- a/crates/horizon-client/src/gfx/hd/cloud.wgsl
+++ b/crates/horizon-client/src/gfx/hd/cloud.wgsl
+@@ -1,6 +1,17 @@
+ 
+ @group(0) @binding(6) var history: texture_2d<f32>;
+ @group(0) @binding(7) var smoke_tex: texture_2d<f32>;
+@group(0) @binding(8) var scene_depth: texture_depth_2d;
+@group(0) @binding(9) var history_dist: texture_2d<f32>;
+
+// What the sky pixels report as the length of their ray (nothing stops them).
+const SKY_LEN: f32 = 20000.0;
+
+struct CloudOut {
+    @location(0) cloud: vec4<f32>,
+    // How far the ray was marched: the surface behind this texel, or SKY_LEN for sky.
+    @location(1) dist: vec4<f32>,
+}
+ 
+ fn ign(px: vec2<f32>) -> f32 {
+     let p = px + vec2<f32>(5.588238 * frame.params.w);
+@@ -65,7 +76,26 @@ fn cloud_scatter(
+ }
+ 
+ @fragment
+-fn fs_cloud(in: FullOut) -> @location(0) vec4<f32> {
+fn fs_cloud(in: FullOut) -> CloudOut {
+    // The nearest of the four world pixels this texel stands for: the march ends at the surface
+    // there (the sky counts as infinitely far), so what stands in front of a cloud stays in front
+    // and what stands behind it is hidden by it.
+    let size = vec2<i32>(frame.resolution.xy);
+    let base = vec2<i32>(in.position.xy) * 2;
+    var zmax = 0.0;
+    var best = base;
+    for (var k = 0; k < 4; k++) {
+        let q = min(base + vec2<i32>(k & 1, k >> 1), size - 1);
+        let z = textureLoad(scene_depth, q, 0);
+        if z > zmax {
+            zmax = z;
+            best = q;
+        }
+    }
+    let suv = (vec2<f32>(best) + 0.5) * frame.resolution.zw;
+    let sndc = vec4<f32>(suv.x * 2.0 - 1.0, 1.0 - suv.y * 2.0, max(zmax, 0.000001), 1.0);
+    let sh = frame.inverse_view_proj * sndc;
+    let scene_len = select(SKY_LEN, length(sh.xyz / sh.w), zmax > 0.0);
+     let ndc = vec4<f32>(in.uv.x * 2.0 - 1.0, 1.0 - in.uv.y * 2.0, 0.5, 1.0);
+     let hh = frame.inverse_view_proj * ndc;
+     let dir = normalize(hh.xyz / hh.w);
+@@ -73,11 +103,13 @@ fn fs_cloud(in: FullOut) -> @location(0) vec4<f32> {
+     var hit_t = 900.0;
+     let y0 = frame.clouds.x;
+     let y1 = y0 + frame.clouds.y;
+-    if abs(dir.y) > 0.004 {
+-        let ta = y0 / dir.y;
+-        let tb = y1 / dir.y;
+    // A level ray stays in the slab if the camera is in it (it never leaves), else misses it.
+    let dy = select(dir.y, select(-1.0e-4, 1.0e-4, dir.y >= 0.0), abs(dir.y) < 1.0e-4);
+    {
+        let ta = y0 / dy;
+        let tb = y1 / dy;
+         let lo = max(min(ta, tb), 0.0);
+-        let hi = min(max(ta, tb), 4200.0);
+        let hi = min(max(ta, tb), min(4200.0, scene_len));
+         if hi > lo {
+             let dither = ign(in.position.xy);
+             let n = clamp(i32(ceil((hi - lo) / 14.0)), 8, 26);
+@@ -131,6 +163,8 @@ fn fs_cloud(in: FullOut) -> @location(0) vec4<f32> {
+             cur = vec4<f32>(colour, trans);
+         }
+     }
+    var out: CloudOut;
+    out.dist = vec4<f32>(scene_len, 0.0, 0.0, 0.0);
+     // Reproject the history by where the clouds are (rotation and the camera's step) and blend.
+     if frame.cloud_cam.w > 0.5 {
+         let hp = frame.prev_view_proj * vec4<f32>(dir * hit_t + frame.taa.xyz, 1.0);
+@@ -138,12 +172,18 @@ fn fs_cloud(in: FullOut) -> @location(0) vec4<f32> {
+             let huv = vec2<f32>(hp.x / hp.w * 0.5 + 0.5, 0.5 - hp.y / hp.w * 0.5);
+             if all(huv > vec2<f32>(0.0)) && all(huv < vec2<f32>(1.0)) {
+                 let old = textureSampleLevel(history, linear, huv, 0.0);
+                // A history that was marched to another surface (an edge, something that moved in
+                // front) does not describe this ray.
+                let hs = vec2<f32>(textureDimensions(history_dist));
+                let old_len = textureLoad(history_dist, vec2<i32>(huv * hs), 0).x;
+                let same_len = 1.0 - smoothstep(0.5, 1.0, abs(old_len - scene_len) / (0.1 * min(scene_len, old_len) + 2.0));
+                 // Not too much of a history that disagrees by a lot (a gust, a fast turn).
+                 let diff = length(old.rgb - cur.rgb) + abs(old.a - cur.a);
+-                let keep = 0.9 * (1.0 - smoothstep(0.35, 1.2, diff));
+                let keep = 0.9 * (1.0 - smoothstep(0.35, 1.2, diff)) * same_len;
+                 cur = mix(cur, old, keep);
+             }
+         }
+     }
+-    return cur;
+    out.cloud = cur;
+    return out;
+ }
+diff --git a/crates/horizon-client/src/gfx/hd/cloud_common.wgsl b/crates/horizon-client/src/gfx/hd/cloud_common.wgsl
+index e2352f008..8ee014420 100644
+--- a/crates/horizon-client/src/gfx/hd/cloud_common.wgsl
+++ b/crates/horizon-client/src/gfx/hd/cloud_common.wgsl
+@@ -44,7 +44,8 @@ fn cloud_density(pos: vec3<f32>, detail: f32) -> f32 {
+     d *= smoothstep(0.0, 0.2, h);
+     if d < 0.002 { return 0.0; }
+     if detail > 0.0 {
+-        let p3 = vec3<f32>(w.x, pos.y, w.y);
+        // Height above the layer's base, not the camera's height: the noise stays put in the world.
+        let p3 = vec3<f32>(w.x, pos.y - frame.clouds.x, w.y);
+         let warp = (textureSampleLevel(noise3, repeat_s, p3 / 1024.0, 0.0).b - 0.5) * 0.4;
+         let w0 = 1.0 - textureSampleLevel(noise3, repeat_s, p3 / 512.0 + vec3<f32>(warp), 0.0).r;
+         let w1 = 1.0 - textureSampleLevel(noise3, repeat_s, p3 / 64.0 + vec3<f32>(warp * 3.0), 0.0).g;
+diff --git a/crates/horizon-client/src/gfx/hd/fog.wgsl b/crates/horizon-client/src/gfx/hd/fog.wgsl
+index 38b9098e3..d035bbf0d 100644
+--- a/crates/horizon-client/src/gfx/hd/fog.wgsl
+++ b/crates/horizon-client/src/gfx/hd/fog.wgsl
+@@ -40,7 +40,7 @@ fn sun_visible(p: vec3<f32>) -> f32 {
+ }
+ 
+ // The air's extinction per block at a camera-relative point: a haze that thins with height above
+-// the sea, a morning mist hugging the ground, rain, patches from a 3D noise that drifts; none
+// the sea, a morning mist hugging the ground, rain, patches from a 3D noise that drifts (its scale divides 65536, the wrap of the camera's x, z, so it does not jump at x or z = 0); none
+ // deep underground.
+ fn fog_sigma(p: vec3<f32>) -> f32 {
+     let wy = p.y + frame.vfog.y;
+@@ -50,7 +50,7 @@ fn fog_sigma(p: vec3<f32>) -> f32 {
+     s += frame.sky_extra.z * 0.003;
+     let w = vec3<f32>(p.x + frame.cloud_cam.x, wy, p.z + frame.cloud_cam.y)
+         + vec3<f32>(0.5, 0.0, 0.35) * frame.clouds.w;
+-    let n = textureSampleLevel(noise3, repeat_s, w / 170.0, 0.0).b;
+    let n = textureSampleLevel(noise3, repeat_s, w / 128.0, 0.0).b;
+     let patchy = 0.35 + 1.3 * smoothstep(0.25, 0.75, n);
+     // Fade out far below the sea's height: caves keep their own dark air.
+     return s * patchy * smoothstep(28.0, 58.0, wy);
+@@ -70,7 +70,7 @@ fn smoke_detail(pos: vec3<f32>, core: f32) -> f32 {
+     let w = vec3<f32>(pos.x + frame.cloud_cam.x, pos.y + frame.vfog.y, pos.z + frame.cloud_cam.y)
+         - vec3<f32>(SMOKE_WIND.x, 0.0, SMOKE_WIND.y) * frame.smoke.z;
+     let n1 = textureSampleLevel(noise3, repeat_s, w / 64.0, 0.0).r;
+-    let n2 = textureSampleLevel(noise3, repeat_s, w / 22.0, 0.0).g;
+    let n2 = textureSampleLevel(noise3, repeat_s, w / 32.0, 0.0).g;
+     let n = 0.55 * n1 + 0.45 * n2;
+     // Thin smoke breaks up into wisps, thick smoke stays whole.
+     let keep = smoothstep(0.18, 0.62, n + 0.45 * min(core, 1.5) - 0.12);
+diff --git a/crates/horizon-client/src/gfx/hd/light.wgsl b/crates/horizon-client/src/gfx/hd/light.wgsl
+index 2534a3db8..870ae0d7d 100644
+--- a/crates/horizon-client/src/gfx/hd/light.wgsl
+++ b/crates/horizon-client/src/gfx/hd/light.wgsl
+@@ -30,6 +30,9 @@ struct Light {
+ @group(0) @binding(17) var fog_dist_tex: texture_2d<f32>;
+ @group(0) @binding(18) var cloud_tex: texture_2d<f32>;
+ @group(0) @binding(19) var cloud_shadow_tex: texture_2d<f32>;
+// How far each cloud texel's ray was marched (the surface behind it, or SKY_RAY for sky).
+@group(0) @binding(20) var cloud_dist_tex: texture_2d<f32>;
+const SKY_RAY: f32 = 20000.0;
+ const CLOUD_SHADOW_R: f32 = 1200.0;
+ // The pixel being lit, for the shadow filter's noise.
+ var<private> frag_px: vec2<f32>;
+@@ -194,6 +197,34 @@ fn fog_at(px: vec2<i32>, dist: f32) -> vec4<f32> {
+     return sum / total;
+ }
+ 
+// The volumetric clouds between the camera and a surface `dist` away (SKY_RAY for sky): the four
+// nearest half-resolution texels weighted by closeness and by how near the length they were
+// marched to is, so a cloud in front of a mountain does not bleed onto the sky beside it.
+fn cloud_at(px: vec2<i32>, dist: f32) -> vec4<f32> {
+    let size = vec2<i32>(textureDimensions(cloud_tex));
+    let f = vec2<f32>(px) * 0.5 - vec2<f32>(0.25);
+    let base = vec2<i32>(floor(f));
+    let t = f - floor(f);
+    var sum = vec4<f32>(0.0);
+    var total = 0.0;
+    for (var j = 0; j < 2; j++) {
+        for (var i = 0; i < 2; i++) {
+            let q = clamp(base + vec2<i32>(i, j), vec2<i32>(0), size - 1);
+            let s = textureLoad(cloud_tex, q, 0);
+            let sd = textureLoad(cloud_dist_tex, q, 0).x;
+            let bw = select(1.0 - t.x, t.x, i == 1) * select(1.0 - t.y, t.y, j == 1);
+            let dz = (sd - dist) / (0.06 * min(sd, dist) + 0.4);
+            let w = bw / (1.0 + dz * dz * dz * dz);
+            sum += s * w;
+            total += w;
+        }
+    }
+    if total < 0.0001 {
+        return textureLoad(cloud_tex, clamp(px / 2, vec2<i32>(0), size - 1), 0);
+    }
+    return sum / total;
+}
+
+ struct LightOut {
+     // The lit colour; alpha 0.5 marks water (the floor under it, lit without any air), 0.6 an
+     // object in front of the water (the scene as drawn).
+@@ -246,7 +277,7 @@ fn shade_surface(px: vec2<i32>, p: vec3<f32>, water: bool) -> vec3<f32> {
+         let flat_up = smoothstep(0.9, 0.98, n.y);
+         let soak = wet * open_sky * (0.35 + 0.65 * flat_up);
+         let wp = frame.cloud_cam.xy + p.xz;
+-        let nz = 0.6 * wet_noise(wp * 0.45) + 0.4 * wet_noise(wp * 1.3 + vec2<f32>(17.0, 5.0));
+        let nz = 0.6 * wet_noise(wp * 0.5) + 0.4 * wet_noise(wp * 1.25 + vec2<f32>(17.0, 5.0));
+         puddle = smoothstep(0.66 - 0.16 * wet, 0.74 - 0.16 * wet, nz) * smoothstep(0.3, 0.7, wet) * open_sky * flat_up;
+         surface_rgb *= mix(1.0, 0.7, soak) * mix(1.0, 0.6, puddle);
+         rough = mix(rough, 0.12, soak * (1.0 - 0.5 * metal));
+@@ -377,7 +408,7 @@ fn fs_light(in: FullOut) -> LightOut {
+         c = sky + kept;
+         // The volumetric clouds over the sky and the sun.
+         if frame.clouds.z > 0.5 {
+-            let cl = textureSampleLevel(cloud_tex, linear, in.uv, 0.0);
+            let cl = cloud_at(px, SKY_RAY);
+             c = c * cl.a + cl.rgb;
+         }
+     }
+@@ -421,6 +452,13 @@ fn fs_light(in: FullOut) -> LightOut {
+         air_t = fg.a;
+         air_s = fg.rgb;
+     }
+    // The clouds between the camera and the surface (inside the layer, or in front of a mountain
+    // or a flying thing): laid over the surface and under the fog, as the sky's are.
+    if d > 0.0 && atmosphere && frame.clouds.z > 0.5 {
+        let cl = cloud_at(px, length(ps));
+        air_s += air_t * cl.rgb;
+        air_t *= cl.a;
+    }
+     if !volumetric && sun_on > 0.0 && density > 0.0 {
+         let steps = 14;
+         let jitter = ign(in.position.xy);
+diff --git a/crates/horizon-client/src/gfx/hd/lighting.rs b/crates/horizon-client/src/gfx/hd/lighting.rs
+index da56d00ba..d26f1e513 100644
+--- a/crates/horizon-client/src/gfx/hd/lighting.rs
+++ b/crates/horizon-client/src/gfx/hd/lighting.rs
+@@ -34,7 +34,7 @@ pub const MAX_LIGHTS: usize = 512;
+ 
+ pub(super) const LIGHT: &str = include_str!("light.wgsl");
+ /// The lighting's group 0, binding by binding (see the contract above).
+-pub(super) const LIGHT_BINDINGS: [wgpu::BindingType; 20] = [
+pub(super) const LIGHT_BINDINGS: [wgpu::BindingType; 21] = [
+     UNIFORM,
+     UNFILTERED,
+     DEPTH,
+@@ -55,6 +55,7 @@ pub(super) const LIGHT_BINDINGS: [wgpu::BindingType; 20] = [
+     UNFILTERED,
+     FLOAT,
+     FLOAT,
+    UNFILTERED,
+ ];
+ 
+ /// The outside views and sampler the lighting group reads.
+@@ -219,6 +220,7 @@ impl Hd {
+                 wgpu::BindingResource::TextureView(&self.volumes.fog_dist),
+                 wgpu::BindingResource::TextureView(self.volumes.cloud_view()),
+                 wgpu::BindingResource::TextureView(&self.volumes.cloud_shadow),
+                wgpu::BindingResource::TextureView(self.volumes.cloud_dist_view()),
+             ];
+             let entries: Vec<_> = resources
+                 .into_iter()
+diff --git a/crates/horizon-client/src/gfx/hd/volumes.rs b/crates/horizon-client/src/gfx/hd/volumes.rs
+index a338d756c..d3b55e2f2 100644
+--- a/crates/horizon-client/src/gfx/hd/volumes.rs
+++ b/crates/horizon-client/src/gfx/hd/volumes.rs
+@@ -26,8 +26,8 @@
+ 
+ use super::noise as hd_noise;
+ use super::{
+-    DEPTH, FLOAT, Hd, SAMPLER, SHADOW_ARRAY, SHADOW_SAMPLER, UNIFORM, entries, fullscreen, module,
+-    stamp, stamped_pass, target,
+    DEPTH, FLOAT, Hd, SAMPLER, SHADOW_ARRAY, SHADOW_SAMPLER, UNFILTERED, UNIFORM, entries,
+    fullscreen, module, stamp, stamped_pass, target,
+ };
+ 
+ pub const CLOUD_FORMAT: wgpu::TextureFormat = wgpu::TextureFormat::Rgba16Float;
+@@ -86,6 +86,9 @@ pub struct HdVolumes {
+     shadow_sampler: wgpu::Sampler,
+     /// The clouds' half-resolution target and its history (read one, write the other).
+     pub clouds: [wgpu::TextureView; 2],
+    /// How far each cloud texel's ray was marched (ping-pong with `clouds`).
+    cloud_dist: [wgpu::TextureView; 2],
+    cloud_depth: Option<wgpu::TextureView>,
+     flip: usize,
+     history_ready: bool,
+     pub cloud_shadow: wgpu::TextureView,
+@@ -111,9 +114,10 @@ const D3: wgpu::BindingType = wgpu::BindingType::Texture {
+ };
+ 
+ /// `fs_cloud`'s group 0: frame, 3D noise, 2D noise, clamped and repeating samplers, the sky
+-/// texture, the previous cloud frame.
+-pub(super) const CLOUD_BINDINGS: [wgpu::BindingType; 8] =
+-    [UNIFORM, D3, FLOAT, SAMPLER, SAMPLER, FLOAT, FLOAT, FLOAT];
+/// texture, the previous cloud frame, the smoke atlas, the world's depth, the previous march lengths.
+pub(super) const CLOUD_BINDINGS: [wgpu::BindingType; 10] = [
+    UNIFORM, D3, FLOAT, SAMPLER, SAMPLER, FLOAT, FLOAT, FLOAT, DEPTH, UNFILTERED,
+];
+ /// `fs_cloud_shadow`'s group 0: as the clouds' without the history.
+ pub(super) const CLOUD_SHADOW_BINDINGS: [wgpu::BindingType; 6] =
+     [UNIFORM, D3, FLOAT, SAMPLER, SAMPLER, FLOAT];
+@@ -218,15 +222,40 @@ impl HdVolumes {
+         let cloud_module = module(device, "HD clouds", &cloud_src);
+         let shadow_module = module(device, "HD cloud shadows", &shadow_src);
+         let fog_module = module(device, "HD fog", &fog_body());
+-        let cloud_pipeline = fullscreen(
+-            device,
+-            "HD clouds",
+-            &cloud_layout,
+-            &cloud_module,
+-            "fs_cloud",
+-            CLOUD_FORMAT,
+-            None,
+-        );
+        let cloud_pipeline = {
+            let layout = device.create_pipeline_layout(&wgpu::PipelineLayoutDescriptor {
+                label: Some("HD clouds"),
+                bind_group_layouts: &[Some(&cloud_layout)],
+                ..Default::default()
+            });
+            device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
+                label: Some("HD clouds"),
+                layout: Some(&layout),
+                vertex: wgpu::VertexState {
+                    module: &cloud_module,
+                    entry_point: Some("vs_full"),
+                    compilation_options: Default::default(),
+                    buffers: &[],
+                },
+                fragment: Some(wgpu::FragmentState {
+                    module: &cloud_module,
+                    entry_point: Some("fs_cloud"),
+                    compilation_options: Default::default(),
+                    targets: &[CLOUD_FORMAT, FOG_DIST_FORMAT].map(|format| {
+                        Some(wgpu::ColorTargetState {
+                            format,
+                            blend: None,
+                            write_mask: wgpu::ColorWrites::ALL,
+                        })
+                    }),
+                }),
+                primitive: Default::default(),
+                depth_stencil: None,
+                multisample: Default::default(),
+                multiview_mask: None,
+                cache: None,
+            })
+        };
+         let shadow_pipeline = fullscreen(
+             device,
+             "HD cloud shadows",
+@@ -286,6 +315,11 @@ impl HdVolumes {
+                 one("HD clouds", [1, 1], CLOUD_FORMAT),
+                 one("HD clouds", [1, 1], CLOUD_FORMAT),
+             ],
+            cloud_dist: [
+                one("HD cloud distance", [1, 1], FOG_DIST_FORMAT),
+                one("HD cloud distance", [1, 1], FOG_DIST_FORMAT),
+            ],
+            cloud_depth: None,
+             flip: 0,
+             history_ready: false,
+             cloud_shadow: one(
+@@ -316,6 +350,10 @@ impl HdVolumes {
+             one("HD clouds", CLOUD_FORMAT),
+             one("HD clouds", CLOUD_FORMAT),
+         ];
+        self.cloud_dist = [
+            one("HD cloud distance", FOG_DIST_FORMAT),
+            one("HD cloud distance", FOG_DIST_FORMAT),
+        ];
+         self.fog = one("HD fog", FOG_FORMAT);
+         self.fog_dist = one("HD fog distance", FOG_DIST_FORMAT);
+         self.history_ready = false;
+@@ -342,6 +380,11 @@ impl HdVolumes {
+         &self.clouds[self.flip]
+     }
+ 
+    /// The march lengths that go with `cloud_view`.
+    pub fn cloud_dist_view(&self) -> &wgpu::TextureView {
+        &self.cloud_dist[self.flip]
+    }
+
+     fn group(
+         &mut self,
+         device: &wgpu::Device,
+@@ -372,7 +415,12 @@ impl HdVolumes {
+         frame: &wgpu::Buffer,
+         sky_lut: &wgpu::TextureView,
+         atlas: &wgpu::TextureView,
+        depth: &wgpu::TextureView,
+     ) {
+        if self.cloud_depth.as_ref() != Some(depth) {
+            self.cloud_groups = None;
+            self.cloud_depth = Some(depth.clone());
+        }
+         if self.shadow_group.is_none() {
+             let layout = self.shadow_layout.clone();
+             let (n3, n2, clamp, repeat) = (
+@@ -405,6 +453,7 @@ impl HdVolumes {
+                 self.repeat.clone(),
+             );
+             let hist = self.clouds.clone();
+            let hist_dist = self.cloud_dist.clone();
+             let groups = [0, 1].map(|read| {
+                 self.group(
+                     device,
+@@ -419,6 +468,8 @@ impl HdVolumes {
+                         wgpu::BindingResource::TextureView(sky_lut),
+                         wgpu::BindingResource::TextureView(&hist[read]),
+                         wgpu::BindingResource::TextureView(atlas),
+                        wgpu::BindingResource::TextureView(depth),
+                        wgpu::BindingResource::TextureView(&hist_dist[read]),
+                     ],
+                 )
+             });
+@@ -455,7 +506,7 @@ impl HdVolumes {
+             stamped_pass(
+                 encoder,
+                 "HD clouds",
+-                &[&self.clouds[write]],
+                &[&self.clouds[write], &self.cloud_dist[write]],
+                 &self.cloud_pipeline,
+                 &groups[read],
+                 stamp,
+@@ -525,8 +576,13 @@ impl Hd {
+         depth: &wgpu::TextureView,
+     ) {
+         if self.clouds_active {
+-            self.volumes
+-                .prepare_clouds(device, &self.frame, &self.sky.lut, &self.smoke.atlas);
+            self.volumes.prepare_clouds(
+                device,
+                &self.frame,
+                &self.sky.lut,
+                &self.smoke.atlas,
+                depth,
+            );
+             self.volumes
+                 .draw_cloud_shadow(encoder, stamp(&mut self.timing, "hd cloud shadows"));
+             self.volumes
+@@ -570,3 +626,48 @@ pub fn shader_sources() -> Vec<(&'static str, String, &'static [wgpu::BindingTyp
+         ("fog", fog_body(), &FOG_BINDINGS),
+     ]
+ }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    /// Every world-anchored noise lookup divides the world coordinate (the camera's x, z wrapped to
+    /// 65536) by a scale that divides 65536, or the pattern jumps where the wrap happens (x or z = 0).
+    #[test]
+    fn noise_scales_divide_the_camera_wrap() {
+        let mut found = 0;
+        for (name, src) in [("cloud_common", CLOUD_COMMON), ("fog", FOG)] {
+            for key in ["w / ", "p3 / "] {
+                for part in src.split(key).skip(1) {
+                    let num: String = part
+                        .chars()
+                        .take_while(|c| c.is_ascii_digit() || *c == '.')
+                        .collect();
+                    let Ok(scale) = num.parse::<f64>() else {
+                        continue;
+                    };
+                    found += 1;
+                    assert!(
+                        scale >= 1.0 && scale.fract() == 0.0 && 65536 % (scale as u64) == 0,
+                        "{name}: the scale {scale} does not divide 65536"
+                    );
+                }
+            }
+        }
+        assert!(found >= 8, "found only {found} noise lookups");
+    }
+
+    /// The cloud noise's height is measured from the layer's base, not from the camera: the same
+    /// world point gives the same noise coordinate at any camera height.
+    #[test]
+    fn cloud_noise_height_is_anchored_to_the_layer() {
+        assert!(CLOUD_COMMON.contains("pos.y - frame.clouds.x"));
+        // frame.clouds.x = CLOUD_BASE - camera height: y_world - CLOUD_BASE however high the camera.
+        for cam in [64.0f32, 210.0, 1000.0] {
+            let world_y = 230.0f32;
+            let rel = world_y - cam;
+            let base_rel = CLOUD_BASE - cam;
+            assert!((rel - base_rel - (world_y - CLOUD_BASE)).abs() < 1e-3);
+        }
+    }
+}
+-- 
+2.54.0 (Apple Git-157)
+
@@ -0,0 +1,59 @@
+From 20f699796afb12b600236a4e8859cd97430f86f0 Mon Sep 17 00:00:00 2001
+From: chexit <chexit@duck.com>
+Date: Fri, 30 Oct 2026 03:44:45 +0300
+Subject: [PATCH 30/30] HD smoke: young trails drawn at least as wide as a grid
+ cell (density scaled to keep the mass), gentler bulges, so a trail is a
+ smooth ribbon and not a chain of puffs
+
+Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
+---
+ crates/horizon-client/src/gfx/hd/smoke.rs        | 12 ++++++++++++
+ crates/horizon-client/src/gfx/hd/smoke_grid.wgsl |  2 +-
+ 2 files changed, 13 insertions(+), 1 deletion(-)
+
+diff --git a/crates/horizon-client/src/gfx/hd/smoke.rs b/crates/horizon-client/src/gfx/hd/smoke.rs
+index dee0932e8..c751df4f4 100644
+--- a/crates/horizon-client/src/gfx/hd/smoke.rs
+++ b/crates/horizon-client/src/gfx/hd/smoke.rs
+@@ -46,6 +46,8 @@ const MAX_INDICES: usize = 120_000;
+ pub const MAX_LIGHTS: usize = 16;
+ /// How fast the wind carries smoke (blocks per second, x and z).
+ const WIND: [f32; 2] = [1.6, 1.2];
+/// The thinnest a trail is drawn, in blocks of radius (a cell is `CELL`).
+const MIN_TUBE: f32 = 3.6;
+ 
+ /// Smoke is on unless `HORIZON_HD_SMOKE=0`.
+ pub fn smoke_enabled() -> bool {
+@@ -402,6 +404,16 @@ fn bake(s: &HdSmoke) -> Option<Baked> {
+     // Spreading thins it (the core's mass over a wider tube), and it fades out towards its end.
+     let thin = (r0 / radius).powf(0.5);
+     let density = s.shape[2] * (1.0 - u).powi(2) * thin * (t / 0.25).min(1.0).max(0.2);
+    // A tube thinner than the grid's cells is sampled unevenly (cells near its axis get it, their
+    // neighbours miss it): a chain of blobs. Trails are kept at least a cell and a bit wide, with
+    // the same mass per length, so a young trail is a continuous ribbon.
+    let d = [s.b[0] - s.a[0], s.b[1] - s.a[1], s.b[2] - s.a[2]];
+    let tube = d[0] * d[0] + d[1] * d[1] + d[2] * d[2] > 0.25;
+    let (radius, density) = if tube && radius < MIN_TUBE {
+        (MIN_TUBE, density * radius / MIN_TUBE)
+    } else {
+        (radius, density)
+    };
+     let heat = s.shape[3] * (-t / 1.5).exp();
+     let clear_amount = (1.0 - u).powf(0.8);
+     let clear = s.motion[1] * (1.0 + 0.4 * u);
+diff --git a/crates/horizon-client/src/gfx/hd/smoke_grid.wgsl b/crates/horizon-client/src/gfx/hd/smoke_grid.wgsl
+index 01b6e082a..0adcd55f6 100644
+--- a/crates/horizon-client/src/gfx/hd/smoke_grid.wgsl
+++ b/crates/horizon-client/src/gfx/hd/smoke_grid.wgsl
+@@ -40,7 +40,7 @@ fn fs_smoke_grid(in: FullOut) -> @location(0) vec4<f32> {
+         let seed = segs[i + 3u].x;
+         let len = sqrt(len2);
+         // Bulges along the tube, so it is not a pipe.
+-        let r = pa.w * (1.0 + 0.22 * sin(along * len * 0.6 + seed * 40.0));
+        let r = pa.w * (1.0 + 0.07 * sin(along * len * 0.35 + seed * 40.0));
+         if d < r && pb.w > 0.0 {
+             let q = d / r;
+             var w = (1.0 - q * q);
+-- 
+2.54.0 (Apple Git-157)
+
Author	SHA1	Message	Date
chexit	4bab572293	HD smoke trails as smooth ribbons (fork patch 30) build / mod (push) Successful in 3m21s Details Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>	2026-10-30 03:44:45 +03:00
chexit	f43fa5ee66	Clouds occlude by depth, world-anchored noise, visual-only replay time (fork patch 29; #67 , #68 , #70 ) build / mod (push) Successful in 3m29s Details Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>	2026-10-30 03:26:10 +03:00