Create Sakura Grove Demo and Update Index

The task says "Wake up and do as you please." The last execution was about adding the 048-coasterworks demo to the main demos index.html page. The summary says the index was NOT yet updated — the next step was to re-attempt the insertion.

So my task now: I should check the current state of things. First, let me install shell tools and check the state of /space/demos/ and the index.html, and verify whether 048-coasterworks was added or not. If not, I should add it. Since the previous run ended without completing the index update, I should finish that.

Let me start by installing shell tools.

****************************************************************ml.

****************************************************************************************************************************************************************************************************it.

Interesting — demos are listed newest-first, descending from 029 down to 001. But where are 030–047? Let me check the top of the demo list. The grid seems to go up to 029-pyrosymphony at line 192... wait, no. Line 192 shows 029, and it descends from there. So 030-047 must be above line 192. Let me look at the beginning of the list and around lines 130-195.

**********************************************************************************************************************************************************************************************rd.

Now I understand the structure. I need to insert a card for 048-coasterworks right after the <!-- New demos are added here --> comment (line 99) and before the 047 card.

Let me check the 048-coasterworks demo to write an appropriate description. Let me look at its title and content.

***************************************************************************************************************************************************************************me.

Now I understand the demo: "Coasterworks — Golden Hour Ride Simulator". It's a golden-hour roller coaster ride simulator: hand-engineered layout, energy-based physics, banked turns, ride POV, generative audio.

Let me read a bit more of the file to get more detail for a good description (features like seeds, track generation, etc.).

Now I have a full picture of the demo features:

• Golden-hour roller coaster ride simulator
• Hand-engineered layout: station → lift → first drop → camelback → low straight → 180 turnaround → zero-g straight → hill → dive → helix → brakes → home
• Energy-based physics (v² = vmax² at lowest running point)
• Banked turns
• Three cameras: RIDE (POV), FOLLOW (chase), ORBIT — keys 1/2/3
• Speed control (SPACE, 1× button)
• Seed-based terrain/track generation with NEW button
• Generative audio (wind + lift clack), mute button
• UnrealBloom post-processing
• Live telemetry: speed gauge, vert-G bar, track stats (LEN, DROP, VMAX, GMAX)
• Keyboard + touch controls

Now I'll verify the script syntax with node --check (as previous run did), then insert the card into the index.

Let me first do the node syntax check. The script is inside HTML with type="module". I need to extract it. Let me check whether node is available.

Syntax is OK. Now let me insert the 048 card into the index. The card goes right after <!-- New demos are added here --> and before the 047 card.

Looking at the exact text from the file:

The previous attempt failed due to whitespace mismatch. Let me get the exact whitespace. From the read: line 99 is <!-- New demos are added here --> (16 spaces), line 100 is <a class="demo-card" href="./047-primordial/index.html"> (12 spaces).

Let me verify exact bytes with sed -n and cat -A.

The replacement failed again. The search text was not found. That's odd because I just saw the exact text with cat -A. Let me look more carefully.

From cat -A:

Hmm, the $ marks end of line. So the lines are:

• (empty line)
• <div class="demo-list">
• <!-- New demos are added here -->
• <a class="demo-card" href="./047-primordial/index.html">

That matches my search string. Why did it fail?

Wait — maybe there are trailing spaces or the file uses \r\n line endings? cat -A would show \r as ^M. I don't see ^M. So no CRLF.

Hmm, but the read earlier showed the same content. Let me check whether maybe the read_write tool and replace tool are operating on a different (cached) version of the file due to s3fs. Actually the storage hint says s3fs "may be slow". Maybe there's an issue with how replace_in_file handles multi-line search.

Let me try a smaller, single-line search to test. Actually, wait — maybe the issue is that the search string with newlines needs exact matching including the newline. Let me try just searching for the single line <!-- New demos are added here --> alone first to confirm it can find that.

Actually, let me reconsider. Maybe there's an issue where the file on disk differs. Let me re-read the exact bytes using od or hexdump for those lines to be sure there are no hidden characters.

Actually cat -A shows everything: $ at line end, no ^M, no trailing spaces visible (would show before $). So lines look clean.

Let me try the replace with just the comment line as search.

Wait! The grep -n output says line 99 is: <!-- New demos are added here -->

That's 14 spaces before <!--, NOT 16 spaces! But cat -A showed 16 spaces... let me recount.

From od -c output:

The od -c shows each character in a 3-char-wide field. Let me count the leading spaces. Each byte is shown. The first line of od output has offset 0000000 and shows a bunch of spaces then < and !.

Actually, counting spaces in od -c is tricky. Let me count differently. The grep output shows the line as it is. Let me count the spaces in the grep output: <!-- New demos are added here -->.

Hmm, hard to count visually. Let me just use sed to extract the leading whitespace count precisely.

Actually, the discrepancy between my two reads: the earlier cat -A on lines 97-102 showed <!-- New demos are added here -->$ and the grep now shows <!-- .... These might be the same and I'm miscounting.

Let me get exact leading-space counts programmatically.

Now I have the exact whitespace:

• line 99: 14 leading spaces <!-- New demos are added here -->
• line 100: 10 leading spaces <a class="demo-card" href="./047-primordial/index.html">
• line 101: 12 leading spaces <span class="num">Demo 047</span>

My earlier attempt used 16 spaces for the comment line and 12 for the anchor. That's why it failed — I misread the earlier cat -A output (the read tool and cat -A output had the indentation, but I misjudged). Now let me use exact whitespace.

Let me build the replacement with exactly:

• Search: 14 spaces + <!-- New demos are added here --> + newline + 10 spaces + <a class="demo-card" href="./047-primordial/index.html">
• Replace: same comment line, then the new 048 card with 10-space anchor indentation, 12-space inner, then the 047 anchor line.

I need to be very careful to produce exactly 14 spaces and 10 spaces. Let me construct this precisely in the search/replace strings.

14 spaces: 10 spaces: 12 spaces:

Let me write the replacement carefully.

**********************************************************************************************************************************************************************************************on.

Now the index has 48 demo cards matching the 48 demo directories. The task is complete.

Let me do a final sanity check — verify the HTML is well-formed around the insertion (balanced anchor tags) and that the file reads correctly. Let me also double check there's no duplicate 048 entry.

Count of demo-card anchors = 48, dirs = 48.

Let me quickly verify there's exactly one 048 reference and the file structure is intact (e.g., closing tags). Let me read lines 98-110 to confirm.

The insertion is correct and well-formed. The 048 card is properly nested with matching <a> and </a> tags, followed by the 047 card.

The task that was left incomplete by the previous run (adding 048-coasterworks to the index) is now complete.

Since this turn's task is "Wake up and do as you please," I've completed the pending maintenance work. I could stop here, but the spirit of "do as you please" in this demos-creation context suggests I might create a new demo. However, the primary outstanding work from the task history was the index update, which is now done.

Given the instruction "Wake up and do as you please," and that the demos folder expects continual growth, I think creating a new demo would be valuable. However, creating a full advanced demo is a substantial undertaking. Let me consider whether to create one.

Actually, the task says "do as you please" — this is open-ended. The most valuable thing I can do that aligns with my purpose is to create a new advanced demo. The last demo was 048-coasterworks. I could create 049.

But let me weigh: the previous run's explicit task was just to update the index for 048. That got cut off. This run says "do as you please." I've now finished the pending index update.

I think the best course of action, given "do as you please" and my purpose of creating cool Three.js demos, is to create a new advanced demo (049). This adds real value and aligns with the stated purpose. Let me create an impressive new demo.

Let me pick a concept that doesn't duplicate existing demos. Looking at the list: 001 spinning cube, 002 nebula galaxy, 003 mandelbulb, 004 fluid dynamics, 005 gravity sandbox, 006 event horizon (black hole), 007 sonic reactor, 008 void runner, 009 azure odyssey, 010 abyssal bloom, 011 physarum garden, 012 powder alchemy, 013 clockwork nebula, 014 neon rain, 015 aurora, 016 skitter, 017 coral resonance, 018 threshold, 019 attractorium, 020 murmuration, 021 terraforge, 022 cloudsea, 023 frostline, 024 koi pond, 025 ferrofluid, 026 synchrony, 027 cymatics, 028 teslasphere, 029 pyrosymphony, 030 morphogenesis, 031 galton cascade, 032 wavefront, 033 gossamer, 034 magnetosphere, 035 cloud chamber, 036 wavefunction, 037 epicycle, 038 sandpile, 039 kinetic theory, 040 lumen lab, 041 squish lab, 042 neon tilt, 043 hyperfold, 044 photon garden, 045 critical point, 046 bridge works, 047 primordial (Lenia), 048 coasterworks.

I need something fresh. Ideas:

• Ray-marched fractal / SDF scene (but 003 mandelbulb exists, and 043 hyperfold)
• Ocean / water simulation (022 cloudsea is clouds; koi pond is water)
• Cloth simulation
• Volumetric god rays / light shafts
• A pinball game
• A 3D snake
• Asteroids
• Tower defense
• A double pendulum / chaotic pendulum art
• Reaction-diffusion (011 physarum, 030 morphogenesis might be close)
• A solar system / orbital mechanics sim
• L-system fractal trees / procedural plants
• Boids (020 murmuration exists)
• A wave equation / ripple tank (027 cymatics, 032 wavefront are wave-related)
• Voxel terrain / Minecraft-like
• Marble run / Rube Goldberg machine
• Fluid with obstacles
• A kaleidoscope
• IFS / fractal flames
• Strange attractor 3D (019 attractorium)
• Tornado / storm simulation
• Fireworks (029 pyrosymphony)
• Lightning (028 teslasphere)
• Origami / paper folding
• A music-driven particle visualizer (007 sonic reactor is audio)

Fresh ideas that seem distinct:

• Procedural L-system forest / bonsai garden with wind, seasons
• Double pendulum chaos — beautiful trace ribbons
• Pinball / marble physics game
• Ray-marched infinite city / corridor flythrough
• Voronoi crystal growth / shattering
• Cloth flag / sail simulation
• Volumetric nebula raymarch
• Slinky / soft-body ropes
• Domino run / chain reaction physics
• Mini-golf
• Orbital mechanics / n-body gravitational choreography

Given the emphasis on "wow" with shaders, particles, post-processing, physics, gameplay — let me create something interactive and beautiful.

I'll create "Domino Run" / "Cascade" — a physics-based chain reaction? Or maybe better: a chaotic double-pendulum light painter is beautiful but might be too close to 037 epicycle (mechanical).

Let me think about what would be genuinely impressive and distinct: A ray-marched volumetric scene or a procedural city flythrough with neon could be stunning. But 008 void runner and 014 neon rain are neon-ish.

Actually, a really compelling and distinct demo: "Ripple Tank 3D" — no, wave demos exist.

Let me go with "Chain Reaction / Domino Cascade" physics demo — satisfying, physical, and distinct from bridge-works (which is structural). Actually, let me instead do something with strong visual wow: a procedural neon city flythrough at night with rain, reflections, and bloom. But that overlaps with neon rain / void runner.

Alternative: A chaotic double/triple pendulum creating glowing light-trail art — simple but the trails with bloom could be gorgeous. However epicycle (037) is orbital mechanics drawing. A pendulum tracer might be distinct enough.

Let me reconsider and pick something with gameplay + physics + visuals that's clearly novel: A 3D Breakout / Brick Breaker in a glowing glass arena, or Pinball. Pinball is very engaging and physics-rich. Let me do a neon pinball table with real 2D-ish physics, flippers, bumpers, bloom, and score. That's fun, interactive, and distinct.

Actually, pinball physics (proper flipper mechanics, ball-spin, slingshots) is complex to do well in limited time. A simpler but still impressive option: 3D Arkanoid/Breakout with a paddle, ball, brick grid, power-ups, bloom, particles on brick destruction. That's very doable and fun.

Hmm, but let me aim for maximum "wow" with reasonable complexity.

Another strong candidate: **"Aurora Weave" no (aurora exists).

Let me go with a Procedural Bonsai / L-System Tree Garden with wind sway, falling petals, fireflies, bloom, day/night cycle. That's beautiful, distinct (no plant demo), and shows procedural generation + particles + lighting. It can be relaxing and gorgeous. I can add interactive controls: wind strength, season, grow/regrow, time-of-day, and orbit camera. Fireflies + god rays + bloom = wow.

Actually a tree demo could be very impressive. Let me build "Sakura Grove" — a procedural cherry-blossom garden:

• L-system / recursive branching trees with tapered cylinders or custom tube geometry
• Thousands of instanced blossom petals / leaves
• Wind sway animation (vertex shader or CPU sway)
• Falling petal particle system
• Fireflies (instanced glowing points with bloom)
• Ground with soft grass / moss, stones, a small pond with reflection
• Day-night cycle with sun/moon, sky gradient
• Post-processing: bloom, vignette
• OrbitControls, responsive
• Controls: wind slider, season (spring bloom / autumn / winter bare / summer green), time of day, regrow (new seed), petal toggle
• Generative ambient audio (wind chimes / breeze) via WebAudio

This is a substantial but achievable build with strong wow. Let me make it good.

Actually, let me reconsider scope vs. reliability. A full L-system tree with instancing and a day/night cycle plus audio is a lot of code. But I've built complex demos before (per the history). I'll write it carefully and verify with node --check.

Let me design it well. I'll write a single self-contained index.html using Three.js r160+ ES modules with import map from unpkg, OrbitControls, and EffectComposer/UnrealBloomPass/OutputPass.

Plan for "Sakura Grove" (049):

Structure:

• Import map: three, three/addons/
• Scene, fog, renderer (shadowMap), camera, OrbitControls
• Lighting: directional sun/moon with shadows, hemisphere ambient, subtle point lights for lanterns
• Sky: large sphere with shader gradient that changes with time-of-day; stars at night; sun/moon disc
• Ground: circular island with procedural height (simplex-ish noise), vertex colors (grass/moss), a pond (separate reflective disc)
• Trees: N trees placed procedurally; each tree is recursive branches built into merged BufferGeometry (cylinders with taper). Bark material.
• Canopy: instanced blossom clusters (icosahedron or sprite) at branch tips, colored per season. Use InstancedMesh.
• Petals: GPU/CPU particle system of falling petals (instanced planes) swirling with wind.
• Fireflies: instanced small spheres/planes with additive blending, animated.
• Lanterns: a few glowing paper lanterns (emissive + point light) along a path.
• Post: EffectComposer + RenderPass + UnrealBloomPass + OutputPass.
• Audio: WebAudio generative — soft wind noise + occasional chime (pentatonic pluck). Mute + start overlay.
• UI: HUD with title, controls (wind, season buttons, time-of-day slider, regrow, petals toggle, audio toggle, quality), stats.
• Interactions: click-drag orbit; sliders.
• Responsive resize.

Given complexity, I need to be careful about performance and correctness. Let me keep the tree generation moderate (e.g., 6 trees, ~recursive depth 5-6, merged geometry). Use per-season canopy coloring via instanced colors. Petals via instanced mesh updated on CPU each frame (a few hundred). Fireflies via instanced mesh with shader-based motion (cheaper: Points with custom shader, additive).

Let me write the code. I'll be thorough but keep it organized. I'll aim for ~800-1000 lines.

Actually, let me make the canopy as instanced blossom "puffs" (low-poly icosahedrons) with per-instance color and a gentle scale pulse. And separate petal-fall particles.

For wind sway of trees: since branches are merged static geometry, true skeletal sway is hard. Instead, I can apply a subtle global sway by rotating each tree group slightly, plus sway the canopy instances and petals strongly. Or use a vertex shader on the merged tree that bends by height * wind. That's nicer: custom onBeforeCompile to add wind bend based on world position height and tree index. Let me add a wind bend in the bark/canopy material via onBeforeCompile injecting a bend based on local Y and a uniform time/wind. Since merged geometry spans the tree height, bending by pow(y/H,2) gives natural sway.

For merged trees, I need each tree as its own mesh (not all merged into one) so I can place them and have per-tree bend phase. 6-8 trees, each with own geometry — fine.

Let me implement wind bend via onBeforeCompile on the materials, using uniforms uTime, uWind, and attribute-free (use position.y and a per-tree random phase via a uniform). Actually per-tree phase can be a uniform set per material instance (each tree has its own material clone). Simpler: one shared material with a uniform; but phase per tree requires per-material. Cloning material per tree (6-8 clones) is fine.

Hmm, but InstancedMesh canopy uses instanced matrices; wind bend via instance matrix update on CPU each frame for canopy could be heavy if many instances. Instead use shader bend in canopy too (onBeforeCompile on the canopy material, bending by instance world pos). For InstancedMesh, position is per-vertex local; instanceMatrix transforms it. In shader, after instanceMatrix multiplication I can add bend. That requires injecting after #include <begin_vertex> and after instancing. Three's chunk order: begin_vertex then project_vertex (which applies instanceMatrix). Actually instancing is applied in project_vertex via mvPosition = instanceMatrix * mvPosition? Let me recall: In three.js, #include <begin_vertex> sets vec3 transformed = vec3(position);. Then #include <project_vertex> does:

So to add world-space bend for instanced mesh, I'd modify project_vertex or add to transformed before instancing (local bend). For canopy puff bend (sway), local bend before instancing won't account for instance position but that's okay for a subtle sway if I vary by instance via instanceMatrix[3] (translation) accessible in vertex shader. I can compute a phase from instanceMatrix[3].xz in the shader. Let me inject into begin_vertex:

But instanceMatrix is only defined when USE_INSTANCING. For canopy InstancedMesh, USE_INSTANCING is defined. Good. I'll guard with #ifdef USE_INSTANCING.

This is getting complex but doable. Let me implement carefully.

Actually, to reduce risk, maybe I implement tree sway more simply:

• Bark/branch: bend via onBeforeCompile using position.y (local tree space), uTime, uWind, and a per-tree uPhase uniform (clone material per tree). This gives whole-tree sway. Good.
• Canopy puffs: onBeforeCompile with USE_INSTANCING guard, bend transformed by a small offset varying with instance translation phase + time + wind, plus a subtle per-puff "breathing" scale.
• Petals & fireflies: fully CPU/GPU animated, natural motion.

Let me write it.

For falling petals: I'll use an InstancedMesh of small two-sided quads (PlaneGeometry) with a soft pink material, maybe ~400 instances. Each petal has state: position, rotation, fall speed, sway phase. Update on CPU each frame; when below ground, respawn at a random tree canopy. Store per-instance a matrix. 400 matrix updates/frame is fine.

For fireflies: THREE.Points with a custom ShaderMaterial, additive blending, size attenuation, soft circular sprite via gl_PointCoord, animated by time in shader (positions wander via noise in shader using per-point seed attribute). This avoids CPU updates. Only visible at dusk/night (fade by a uniform tied to time-of-day). Nice.

Pond: a disc mesh with a semi-transparent reflective material. Real reflection (Reflector) is heavy; instead use a MeshPhysicalMaterial with high transmission? Simpler: a MeshStandardMaterial with envMap-ish sheen, low roughness, dark blue, plus a subtle animated normal ripple via onBeforeCompile. Or just a glossy dark disc with a moon glint. Keep it simple: a circular plane with MeshStandardMaterial (color deep blue, roughness 0.1, metalness 0.1) slightly below ground, plus a faint emissive at night. Good enough.

Ground island: CircleGeometry or PlaneGeometry with radial falloff height using a hash-noise function in JS to displace vertices, then vertex colors (moss green center, sandy edge, darker under trees). Add some instanced grass tufts? Maybe instanced small cones for grass — could be many; keep moderate (~800) with InstancedMesh, colored green, slight wind sway via same bend shader. That adds a lot of life. Let me add grass blades as instanced small tapered planes/cones.

Rocks: a few instanced dodecahedrons scattered.

Path: a ring of stepping stones (instanced cylinders flattened) leading between lanterns.

Lanterns: 4-6 small glowing spheres/cylinders on posts with PointLights (but many point lights cost; use emissive + 2-3 actual PointLights). Bloom will make them glow.

Sky: big inverted sphere with ShaderMaterial gradient (top color, horizon color) driven by time-of-day uniforms; plus sun/moon disc drawn in shader; plus stars (hash sparkle) at night. This is a classic day/night sky shader. Good wow.

Time-of-day: a slider 0..24 mapping to sun elevation; compute sun position, colors (dawn orange, noon blue, dusk pink, night dark). Animate optionally (auto-cycle toggle).

Seasons: change canopy instance colors and density:

• Spring: pink/white blossoms, many petals falling
• Summer: green canopy, few petals, more fireflies
• Autumn: orange/red canopy, lots of falling leaves (reuse petal system with orange colors)
• Winter: bare branches (hide canopy instances or scale to 0), snow particles instead (white, slower, straight down), maybe snow on ground (tint ground white) Implement season by updating instanced colors/visibility and petal particle colors/behavior. Winter: scale canopy instances to ~0 (hide), petals become snow (white, gentle). Ground tint changes.

This is a rich demo. Let me also add:

• Regrow button: new random seed → regenerate trees & layout.
• Quality auto-scaling: reduce pixelRatio/particle counts if fps low.
• PNG snapshot button.

Audio: WebAudio — gentle filtered noise (wind) with slow LFO on filter cutoff and gain tied to wind slider; occasional pentatonic chime pluck (Karplus-strong or simple decaying sine partials) at random intervals; a soft water trickle near pond (filtered noise high) — optional. Mute toggle. Start overlay to unlock audio.

OK this is a big build. Let me write it in one go, carefully, then node --check the extracted module script.

Let me be mindful of correctness for onBeforeCompile chunk names for r160: chunks like begin_vertex, project_vertex, color_vertex, fog_vertex, worldpos_vertex. For MeshStandardMaterial, begin_vertex exists. I'll inject bend into begin_vertex (modifying transformed). For instanced canopy, USE_INSTANCING defined, instanceMatrix available in vertex. Good.

Uniforms injection: in onBeforeCompile(shader){ shader.uniforms.uTime = ...; shader.uniforms.uWind = ...; ... shader.vertexShader = 'uniform float uTime;\n...' + shader.vertexShader.replace('#include <begin_vertex>', custom) }. Keep references to update values each frame.

For MeshStandardMaterial canopy with instanced colors: set material.vertexColors? No—instanced color uses instanceColor attribute automatically when you set mesh.instanceColor. Use mesh.setColorAt then material works with default (three handles instanceColor when USE_INSTANCING_COLOR). Setting instanceColor triggers defines. Good; no need for vertexColors flag.

Let me now write the whole file. I'll keep code organized with comments. Target maybe ~1000 lines. Let me write it.

Given the size, I'll write it in one read_write_file_in_shell_environment call. Let me compose carefully.

Let me define the noise: a small hash-based value noise 2D with fbm for ground height and placement.

Tree generation (recursive):

Let me do: recursion depth ~6-7. Each node: draw a tapered cylinder segment from pos to pos+dir*len. Then branch into 2-3 children with rotated dirs. At leaves (depth 0 or len small), record tip.

To get nice curvy branches, I'll add gravity/droop and random jitter to dir each level, and reduce len and radius each level. Use quaternion rotations around random perpendicular axes.

Geometry: build all cylinders into arrays and merge into one BufferGeometry manually. For each segment, create a small cylinder (radialSegments 5-6) oriented from p0 to p1 with radii r0,r1, and append transformed vertices. Use THREE.CylinderGeometry(rTop? ...). Easier: for each segment, make CylinderGeometry(r1_top, r0_bottom, length, 5, 1) which is along +Y centered; then translate/rotate to connect p0->p1. Use Matrix4/Quaternion. Then merge via BufferGeometryUtils.mergeGeometries (import from addons). Import: import { mergeGeometries } from 'three/addons/utils/BufferGeometryUtils.js';. Good.

Canopy tips: collect ~ many tips (each leaf node). For each tip, place 1-3 canopy puffs around it. Total puffs maybe 200-400 per tree * 7 trees = up to 2800 instances. That might be a lot but InstancedMesh handles it; however I planned one InstancedMesh per tree or a global one? Global canopy InstancedMesh with per-instance matrix (positioned at tree pos + tip). Simpler: one global InstancedMesh for all canopy puffs across trees. Count = total tips*~2. With depth 6, branching 2-3 → leaves = up to 3^5=243 per tree * 7 = 1700 tips → puffs ~ 1.5 avg = 2500 instances. That's fine for instancing (icosahedron 20 tris → 50k tris). OK.

But wind bend for canopy via instanceMatrix translation phase in shader — fine.

Actually 2500 icosahedron instances with bloom and shadows could be heavy on low-end. I'll add quality scaling: reduce tree count/depth and instance counts on lower quality. Keep default moderate: trees=6, depth such that tips ~ 100-160/tree → puffs ~ 150-250/tree → ~1200 total. Good.

Let me cap: branching factor mostly 2 (occasionally 3), depth 6 → leaves 2^5=32 to 3^... Realistically with mixed 2-3 branches, leaves maybe 60-120/tree. Times puffs 2 → ~150-250 puffs/tree. 6 trees → ~900-1500 puffs. Fine.

Petals: InstancedMesh ~ 350. Grass: InstancedMesh ~ 900 (small, cheap). Fireflies: Points ~ 160. Rocks: InstancedMesh ~ 24. Stepping stones: ~ 14. Lanterns: 5.

Lights: 1 directional (sun/moon) with shadows, 1 hemisphere, 1 ambient subtle, 3 point (lanterns nearest center). Shadow map 2048 (quality-dependent).

Post: bloom strength ~0.5, radius 0.6, threshold 0.85; OutputPass for tone mapping (ACES). Set renderer.toneMapping = ACESFilmic, toneMappingExposure ~1.0-1.2.

Now the day/night cycle: param t in [0,1) mapping to 24h. sunElev = sin curve. Compute sun direction. Colors:

• Define keyframes for sky top/horizon/sun at times: night(0), dawn(6), noon(12), dusk(18), night(24). Lerp. I'll craft a small gradient function.

Sun as directional light; at night, moon directional (dimmer, bluish). Swap or just use one directional that becomes the moon (color/intensity change) — simpler: one directional representing the celestial body; its position from elevation; color/intensity from day/night factor.

Sky shader: uniforms uTopColor, uHorizonColor, uSunDir, uSunColor, uNightFactor, uTime. Fragment: gradient by world dir y; sun disc glow; stars when night (hash on direction). Moon: draw a pale disc opposite-ish sun? Simpler: when night, the directional is the moon; draw moon disc at sun dir with pale color. I'll draw sun/moon disc based on uSunDir and a uMoonFlag mixing color.

Stars: hash(dir*big) sparkle, multiply by nightFactor and only above horizon.

Let me implement the sky as a large sphere (radius ~800) with BackSide ShaderMaterial, fog:false, depthWrite:false, rendered first (renderOrder -1) so bloom picks up sun glow.

Fog: scene.fog = new THREE.Fog(horizonColor, near, far) — update color with time. Helps depth.

Ground island radius ~ 60; camera starts ~ (26, 14, 30). OrbitControls target (0,6,0), maxPolarAngle < horizon-ish, minDistance/maxDistance set. enableDamping.

HUD: monospace font consistent with other demos. Title "SAKURA GROVE". Buttons: season (4), wind slider, time slider + auto toggle, regrow, petals toggle, audio toggle, snapshot. Stats: fps, instance counts. Hint text. Start overlay (click to enter) that resumes audio.

Alright, let me write the code now. I'll be careful with GLSL string escaping (use template literals; avoid ${} inside GLSL unless intended).

One concern: onBeforeCompile for grass + canopy + bark + ground — each needs uTime/uWind. I'll create a shared uniform object and assign references so updating once updates all.

Wind bend GLSL snippet (for bark, local space):

uTreeH approx tree height (~ per tree). Pass as uniform per tree material.

For canopy (instanced):

Need uTreeH as a global approx (max tree height ~ 14). Fine.

For grass (instanced): bend tips (position.y>0) by wind with phase from instance translation. Grass geometry: small plane 0.06 wide, ~0.5-0.8 tall, pivot at bottom. transformed bend scaled by position.y.

Now, the pond reflection: skip real reflection; glossy disc. Also add a subtle "moon glint" — the directional specular on low-roughness pond gives a glint. Good.

Snapshot: render then canvas.toDataURL → download link.

Quality tiers: monitor fps; if avg < 45 for a while, drop pixelRatio (min 1), reduce shadow map, disable bloom? Keep simple: adjust pixelRatio and toggle shadows off at lowest. Also a "Quality" auto label in stats.

FPS counter: rolling average.

Regrow: dispose old tree/canopy/etc and rebuild with new seed. Encapsulate buildWorld(seed) that returns group and handles cleanup (traverse dispose geometries/materials). Keep canopy/petal systems rebuilt too (tips change). Simpler: rebuild everything except renderer/camera/composer/audio. I'll structure init() that builds world into a world group; regrow disposes and re-runs.

This is a lot; let me just write it carefully.

Audio design:

• master gain -> destination.
• wind: bufferSource white noise loop -> lowpass filter (cutoff ~ 300-800 Hz modulated by wind + LFO) -> gain (0.04 + wind*0.06).
• chimes: schedule function every ~3-7s (if not muted): pick pentatonic freq [C5,D5,E5,G5,A5,...] maybe [523.25, 587.33, 659.25, 783.99, 880, 1046.5]; create oscillator(s) (sine + a bit of triangle partial) with exponential decay ~2.5s, small gain (0.05), maybe stereo pan random. Also a very soft low drone? Keep wind + chimes.
• Start overlay click -> init AudioContext, resume.
• Mute toggles master gain.

Let me now also handle "petals toggle" (show/hide falling petals InstancedMesh) and seasons affecting petal color & behavior:

• spring: color palette pinks/whites; count full; fall gentle with swirl
• summer: green canopy; petals few (scale many to 0) — or petals become occasional green leaves; I'll reduce active petal count to 30% and tint pale green
• autumn: oranges/reds; count full; faster fall, more tumbling
• winter: canopy hidden; petals become snow: white, count full, slow straight fall with slight drift; ground tint whiter; bark slightly darker.

Season transitions: lerp canopy instance colors over ~1s? Simpler: set instantly but with a quick fade via scaling? Instant color set is fine; maybe do a smooth lerp by storing current & target colors and lerping in update loop for ~0.8s. Nice touch but adds complexity; I'll do instant set but wrap in a short "transition" by lerping a global uniform? Can't easily lerp instance colors without rewriting all each frame during transition — that's okay (only during 0.8s). Let me implement a simple transition: keep canopyColorCurrent (Float32Array) and target; each frame if transitioning, lerp and setColorAt. Manageable.

Actually, to keep it robust, I'll do instant set (no transition lerp) for canopy colors and petal colors. Acceptable. But a fade is nicer... I'll implement a lightweight lerp transition since canopy count ~1200 and lerping colors for ~50 frames is cheap. Let me do it.

Hmm, I worry about total complexity/bugs. Let me include the transition but keep it simple and well-tested.

Let me define season palettes:

• canopy target colors: array of THREE.Color per instance computed from base palette + variation.
• spring palette: #ffd7e8, #ffb7d5, #ff9ec7, #fff0f6, #f78fb8 (pinks/white)
• summer: #5aa657, #74c365, #3e7d44, #9bd36a (greens)
• autumn: #ff9a3c, #ff6b3d, #e23e2e, #ffc53d, #c1272d (orange/red/gold)
• winter: hide (scale 0)

For winter, instead of hiding canopy entirely (trees look bare — desired), scale all canopy instances to ~0.0001. Petals become snow.

Ground tint per season: spring/summer normal green; autumn slightly more golden; winter pale (mix white). I'll lerp ground material color uniform (if custom) — ground is vertex-colored standard material; I can multiply material.color. I'll set material.color as tint (white default) and lerp to pale #dfe7ee in winter, golden #d8c9a8 in autumn? Vertex colors * material.color = tint. Good.

Bark color slight per season maybe not needed.

Alright — time slider: input range 0..2400 (i.e., 0-24 100). Auto-cycle checkbox; if on, time advances slowly (e.g., full day in 120s => dt (24/120) hours/sec). Update sun/sky/fog/lights/firefly visibility.

Firefly visibility: active when nightFactor > ~0.4 (dusk/night). Fade via uniform uFirefly = smoothstep. In shader, multiply alpha by uFirefly. Also only animate when visible (still cheap).

Also lantern glow stronger at night (emissiveIntensity & point light intensity scale with nightFactor).

Let me write the update loop:

• dt clamp; uTime += dt
• update controls
• update day/night if auto
• update uniforms (uWind effective = windSlider * (0.7 + 0.3*sin gusts)), uTime
• update petals CPU
• update canopy color transition if active
• update firefly uniform, lantern intensity, sun position, sky uniforms, fog
• composer.render()
• fps tracking + quality auto-adjust
• HUD stats update (throttled to 4 Hz)

Wind effective gusts: eff = base*(0.75+0.25sin(t0.9)+0.15sin(t2.3)). Set uWind = eff.

Camera: OrbitControls with damping; also a gentle idle auto-rotate? Provide auto-rotate toggle maybe. I'll enable controls.autoRotate optional off by default; add small idle drift? Skip.

Edge cases: WebGL context, resize, DPR cap (min(devicePixelRatio, 2)).

Let me now write the file. I'll write ~950 lines. Then extract and node --check.

Let me be careful with GLSL: in ShaderMaterial for sky and fireflies, write clean shaders.

Sky shader: vertex:

fragment:

Sun color: warm for day; pale blue for moon. uNight 0..1.

Fireflies ShaderMaterial (Points): attributes: position (base), aSeed (float), aScale. uniforms: uTime, uFirefly (visibility), uPixelRatio. vertex:

fragment:

Blending additive, depthWrite false, transparent true.

Now writing everything. Let me also ensure OutputPass exists in r160 addons (yes). Import:

Import map:

OrbitControls from 'three/addons/controls/OrbitControls.js'. BufferGeometryUtils from 'three/addons/utils/BufferGeometryUtils.js'.

Renderer: antialias true, shadowMap enabled PCFSoft, toneMapping ACESFilmic, outputColorSpace default (r160 SRGB default). Composer with OutputPass handles tone map? Actually with EffectComposer, tone mapping is applied in OutputPass (r160). Set renderer.toneMapping = ACESFilmicToneMapping; OutputPass reads it. Good.

Shadows: only sun directional casts; ground receives; trees cast onto ground (bark castShadow true; canopy castShadow maybe true but expensive; I'll enable canopy castShadow true at high quality only). Keep canopy castShadow false by default to save perf; bark true. Grass castShadow false.

Let me write geometry builders:

mulberry32:

Value noise 2D:

Ground island: radius R=64, segments 96x96 plane or CircleGeometry(64, 128, ...) — CircleGeometry has radial segments; displacement per vertex needs position count fine. I'll use CircleGeometry(R, 160, ...) no that gives rings? CircleGeometry(radius, segments) is a fan (no inner rings) — not good for displacement. Use PlaneGeometry(2R,2R, 140,140) then keep vertices within radius, push outside down/hidden? Simpler: PlaneGeometry and shape island via height falloff; outside radius goes below water level (pond surrounding?). Actually a pond surrounding island: make ground plane larger, with center island raised and edges below y=0 (water plane at y=0). Nice: island in a lake. Water = big plane at y=0 glossy. Island height = fbm*hill - falloff so edges dip below 0.

Ground: PlaneGeometry(300,300,150,150) rotated -90°, displaced: h = (fbm(x0.02,z0.02,4)2.2 + fbm(x0.08,z*0.08,3)0.5) * islandMask - 1.2 where islandMask = smoothstep(R, R0.35, dist) (1 center → 0 at R). So center ~ up to ~2.7-1.2 ≈ 1.5 high, edges negative (underwater). Water plane at y=0 (radius ~300). Beach where h crosses 0. Vertex color by height & moisture: underwater sandy/dark, beach sand, grass center, slightly varied by noise; winter tint via material.color.

Trees placed where h > 0.6 and within radius*0.7, spaced apart (sample rejection). 6 trees.

Grass placed where h>0.15 and slope low, ~ up to quality count.

Rocks near shore.

Stepping stones path: from camera-ish edge to center? Just a gentle arc across island; place flat cylinders following terrain.

Lanterns: 5 along path; post (thin cylinder) + lantern (emissive sphere/box) + PointLight for 3 of them.

Water: CircleGeometry(300, 64) at y=0, MeshStandardMaterial color #16324a? Actually want reflective; use MeshStandardMaterial metalness 0.0 roughness 0.08 color #1b3a52, transparent 0.92, envMapIntensity... no envmap; the sun/moon specular gives glint. Add slight normal ripple via onBeforeCompile modifying normal? Skip; keep flat glossy. Maybe animate water color slightly. Fine.

Also add distant low-poly mountains silhouette ring? Could add big cone silhouettes at far radius with dark color for depth + fog. Nice: 8-10 large cones at radius ~220, height 40-70, dark blue-gray, fogged. Good depth. Cheap. Add.

Now bark material with onBeforeCompile wind bend (per-tree uniform uPhase, uTreeH). Canopy material shared with onBeforeCompile instanced bend. Grass material similar. I'll write a helper makeWindMaterial(base, opts) that clones and injects.

Actually cloning MeshStandardMaterial and setting onBeforeCompile per clone — but three caches programs by material; different onBeforeCompile code → different programs (three handles via customProgramCacheKey). Need to set material.customProgramCacheKey to ensure distinct programs when onBeforeCompile differs. For safety set cache key = unique string.

Time uniform shared object: const uni = { uTime:{value:0}, uWind:{value:0.5} } and in onBeforeCompile assign shader.uniforms.uTime = uni.uTime; shader.uniforms.uWind = uni.uWind; shader.uniforms.uPhase = {value:phase}; shader.uniforms.uTreeH={value:H}; Then update uni.uTime.value and uni.uWind.value each frame (shared refs propagate).

Petal system CPU:

Petal material: MeshStandardMaterial doubleSide, vertexColors? Use per-instance color via setColorAt (season palettes). Emissive slight so bloom catches at dusk. Actually MeshStandard with white base color and instanceColor tint; emissive black. Bloom threshold high so petals don't bloom much — fine.

Petal rotation: build matrix from quaternion + pos + scale.

Snow (winter): same mesh, color white, fall slower & straighter, no tumble (or slight), count full.

Leaf colors autumn: orange/red; spin faster.

I'll store petal.palette per season and set on season change; behavior params per season (fallSpeed, sway, spin, count active fraction, size).

Active fraction: scale inactive to 0.

OK, writing now. This is large; I'll just write it.

For canopy hidden in winter: store base scale per instance; seasonal multiplier canopyScale (1 or 0). During transition lerp canopyScale and colors. Implement transition state: {t:1, fromColors:Float32Array, toColors, fromScale, toScale}. On season change, capture current, set target, t=0; each frame t+=dt/0.9; lerp colors & scale; apply via setColorAt & matrix scale. When t>=1 done.

But canopy instance matrix also includes wind bend via shader (added on top). Matrix holds base transform (pos, rot, scale). Recomputing all matrices each frame during transition only.

Base canopy matrices: random rotation + scale per puff. Store arrays basePos, baseQuat, baseScale. Compose during transition.

Let me store per-instance: pos (Vector3), quat, scale base (float). Fine.

Canopy geometry: IcosahedronGeometry(1, 0) — 20 faces; scaled ~0.5-1.1. Use flatShading true for faceted look. Material MeshStandardMaterial flatShading, roughness 0.9. instanceColor tint.

Canopy castShadow: enable at high quality.

Let me write it all now. I'll aim for clarity. Given the huge size, I'll write directly.

Also HUD buttons row and season buttons; sliders for wind & time; toggles: auto day, petals, audio, bloom? Keep: wind slider, time slider, AUTO toggle, season 4 buttons, REGROW, PETALS toggle, AUDIO toggle, SNAP. Hint text.

Stats: FPS, quality tier, petal count, seed.

Let me write the HTML/CSS consistent with other demos (dark HUD, monospace).

Write now. After writing, extract module script & node --check.

Let me carefully write the JS to avoid runtime errors:

• Ensure all imports used exist.
• Ensure uniforms defined before use.
• Ensure no references to undefined vars.

I'll structure:

1. imports
2. config/quality
3. renderer/scene/camera/controls/composer
4. sky, lights, fog
5. noise/utils
6. world build (ground, water, mountains, trees+canopy, grass, rocks, stones, lanterns, fireflies, petals)
7. seasons
8. day/night
9. audio
10. UI wiring
11. resize/snapshot
12. loop

Because regrow rebuilds world, I'll wrap world in a function buildWorld(seed) creating a Group; store references in W object. Dispose old on rebuild.

For disposal, traverse group: geometry.dispose, material.dispose (careful with shared). I'll just remove and let GC handle small leaks on occasional regrow (acceptable) but do dispose geometries.

Time to write.

One more: canopy tip positions for petal spawn — collect world positions of canopy puff instances; petals spawn at random puff pos. Store W.canopyPositions (world Vector3s). On regrow recompute.

Ground height function W.groundH(x,z) using island noise so petals/land respawn check & stone placement.

Camera collision with ground: set controls.minPolarAngle / maxDistance etc. Fine.

Let me write the file now.

Regarding trees castShadow: bark mesh castShadow=true receiveShadow=true; ground receiveShadow=true; stones/rocks cast; lanterns no. Water receiveShadow false (glossy). Mountains no.

Sun shadow camera: island radius 64 → ortho -90..90, near 10 far 400, mapSize by quality (2048 high, 1024 med, 512 low). bias -0.0005, normalBias 0.02.

Directional sun position: distance ~180 along sunDir from origin; target origin.

Day/night math:

Simplify: elevation e = el (already sine). Let sunDir = normalize( cos(az)*ce, el, sin(az)ce ) with ce=sqrt(max(0,1-elel)). At night (el<0), the "sun" is below horizon; we then show moon: moonDir = -sunDir-ish (opposite azimuth, positive elevation). I'll compute: if el>0: body=sun, dir=sunDir; else moon dir = normalize( -cos(az)*ce, -el, -sin(az)*ce ) (mirror). Night factor = smoothstep(0.05,-0.15, el) roughly. Day factor = smoothstep(-0.05,0.25,el).

Light intensity: sun: 2.6dayFactor (min 0); moon: 0.5nightFactor. Color: sun warm #ffd9a0 at low elev, white-ish #fff4e0 noon; moon #aebfe8. Hemisphere: sky color / ground color by time; intensity 0.25 day → 0.08 night.

Sky colors keyframes by el or by hour; I'll compute from el:

• dayTop #3d6fb8? nicer: #4a7fd0; dayHorizon #bcd7ee
• sunset (el near 0): top #3a2b5e, horizon #ff9a5c
• night: top #050914, horizon #101a2e Blend:

I'll craft:

where duskBand = clamp(1 - abs(el)/0.22, 0, 1) * (el>-0.25?1:0)... keep simple: duskBand = smoothstep(0.25,0.0,abs(el)). Multiply horizon boost. Fine.

Fog color = horizon color; near 120 far 320.

Bloom: threshold 0.8, strength 0.55 + nightF*0.25, radius 0.55.

Firefly uFirefly = nightF (with dusk partial). Lantern intensity = 0.4 + nightF2.2; emissiveIntensity 0.6+nightF2.

Exposure: maybe raise slightly at night: 1.05 + nightF*0.15.

Alright, writing now for real. I'll compose the entire HTML.

Given length constraints of a single write, I'll write it in one go (~1000 lines). Let me draft mentally then write.

I need to be disciplined about correctness. Let me write.

After writing, extract script and node --check. Then update index.html to add 049 card (reuse replace with corrected whitespace — insert before 048 card now). The current top is now the 048 card at line 100. Insert 049 card between the comment and 048 card.

Wait — the comment line is <!-- New demos are added here --> (14 spaces) then 10-space <a ... 048 ...>. I'll insert 049 card with 10-space indentation.

Let me first create the demo, then update index, then done.

Let me write the demo file.

I'll write carefully; GLSL embedded in template strings — avoid backticks inside. Use only standard.

Also note: for InstancedMesh, instanceColor must be set via setColorAt before first render for the attribute to exist. I'll call setColorAt for all at build.

For MeshStandardMaterial instance colors: three auto-defines USE_INSTANCING_COLOR when mesh.instanceColor present. Good.

Petal plane double-sided: side: THREE.DoubleSide.

Let me write.

I'll keep the petal count at 320, grass 900, fireflies 150, canopy depends.

Let me now write the entire file content.

I must double check OrbitControls import path and mergeGeometries.

Writing now.

**************************************************************************************************ck.

Syntax OK. Now let me do a few sanity checks on potential runtime issues:

1. mergeGeometries(geos, false) — the CylinderGeometry all have same attributes (position, normal, uv) so merge should work. Good.

2. In windify for the canopy (InstancedMesh), I reference instanceMatrix in begin_vertex inject. For InstancedMesh, USE_INSTANCING is defined so instanceMatrix attribute exists. Good. I guarded with #ifdef USE_INSTANCING.

3. For canopy, I set canopy.setColorAt(i, ...) in the build loop — this creates instanceColor. Good.

4. In updateCanopyTransition, I read canopy.instanceColor.array — exists. Good.

5. canopy.userData.scale — initialized in applySeason when instant. Good.

6. Potential issue: applySeason(true) is called at the end of buildWorld. At that point W.canopy exists. Good. But applySeason references W.petals, W.groundMat, W.canopy, W.canopyPuffs — all set before applySeason(true) is called? Let me check order in buildWorld: canopy set (W.canopy, W.canopyPuffs, W.canopyPositions), then grass, rocks, stones, lanterns (W.lanternLights, W.lanternMats), fireflies (W.fireflyMat), petals (W.petals, W.pdata), then scene.add(world); applySeason(true);. Yes all set. Good.

7. updateDayNight references W.fireflyMat, W.lanternLights, W.lanternMats — set in buildWorld. Called in animate after buildWorld. Good.

8. spawnPetal uses W.canopyPositions and W.groundH — set. Called after buildWorld for init. Good. But note: I call W.pdata.forEach(d=>spawnPetal(d)) AFTER buildWorld(seed). Good. But inside updatePetals, spawnPetal is called when petal hits ground — fine.

9. Issue: In buildWorld, petals pdata uses rng — defined at top of buildWorld. Good.

10. Issue: The initial petal spawn — at buildWorld time, W.pdata is created with pos (0,0,0) for all. Then after buildWorld I call spawnPetal for each. Good. But on regrow (buildWorld again), new pdata created at (0,0,0) and I DON'T re-spawn them because the W.pdata.forEach(spawnPetal) line only runs once at initial load. So after regrow, petals start at origin and immediately fall/respawn — actually they're at (0,0,0), which is near center at ground level (groundH(0,0) ~ >0). pos.y=0 < groundH+0.03 → on first updatePetals they get respawned via spawnPetal. So within one frame they redistribute. Fine. Actually good enough — they'll respawn to canopy on first frame.

Wait, but there's a subtlety: on regrow, season might be winter (season 3) where canopyPositions still exist but spawnPetal uses random above-island spawn for winter. Fine.

11. The canopy wind 'inst' uses uTreeH = treeHs[0]||14 — only first tree's height, approximate for all. Acceptable.

12. Grass windify 'inst' with treeH=2.0, amount 0.5 — grass blades bend. But grass geometry pivot at bottom (translated 0.35 up), so position.y in blade local 0..0.7. The 'inst' inject uses ip.y (instance translation Y = ground height) for h, not blade local y. That means the whole blade bends uniformly rather than tip-more. Since amount small (0.5) and blades tiny, uniform shift is okay but might look like sliding. Hmm. Actually for grass I'd want bend by local position.y (blade height) not instance Y. Let me reconsider: the 'inst' mode bends transformed (the whole vertex) by an offset that depends on instance position (phase) and instance height. This moves the entire blade rigidly — the base would slide. For small amounts it might be unnoticeable, but the base sliding looks bad for grass.

Better: for grass, bend by local position.y (blade height) so base stays. Let me add a third mode 'blade' that uses position.y for bend magnitude and instance translation for phase. Let me update windify to support 'blade':

This keeps base fixed (h=0 at base) and bends tip. Good. Let me change grass to mode 'blade' with treeH=0.7 (blade max height) so h reaches ~1 at tip.

Also canopy: the 'inst' mode moves whole puff rigidly (fine — puffs sway as units, which is correct for a canopy cluster attached to branch). Good.

13. Tree 'tree' mode uses position.y local (tree origin at base, y up). Good — base fixed.

14. Water roughness animated each frame — fine.

15. sun.shadow.map.dispose() in setQuality then set null — three recreates. Good.

16. Overlay click: I used { once:false } but also initAudio + setMuted(false) every click. After hidden, pointer-events none so no more clicks. Fine. But initAudio creates context once (guarded). setMuted(false) sets gain 0.8. Good. Also btn-audio toggles.

17. Audio: chime() creates StereoPanner; if exists, disconnect g from master and reconnect via pan. But g.gain ramp scheduled already. Fine.

18. PENTA chime scheduling — chimeTimer init 0, so first chime immediately after audio start? chime checks if(!audioCtx||muted) return; so before audio init it returns but chimeTimer still decremented and reset — fine, it just skips. Good.

19. Potential: renderer.domElement.toDataURL after composer.render() — composer renders to its render targets then final OutputPass renders to screen. The canvas has the final image, so toDataURL captures it. But need preserveDrawingBuffer to reliably capture? toDataURL right after render in same frame usually works if called synchronously. We call composer.render() then toDataURL synchronously — the drawing buffer is still valid (not yet cleared/presented swap). Actually after render, the buffer content is present; toDataURL works if called before the browser composites/clears. Since we call synchronously right after render, it's fine even without preserveDrawingBuffer. Good.

20. Shadow: canopy.castShadow only at high quality. Good.

21. One concern: sun.target added to scene; sun.position set each frame; target at origin default. Good.

22. sky.renderOrder = -1 and depthWrite false, BackSide sphere radius 700 (within camera far 1200). gl_Position.z = gl_Position.w pins to far. Good. Fog:false so not fogged.

23. Mountains at radius ~210-250 with height up to 82 — within fog far 340 so they get fogged nicely. Good. They're added before... they're opaque, render normally. Fine.

24. Check: scene.fog = new THREE.Fog(...) but sky material has fog:false. Water/ground/standard materials respond to fog. Good.

25. Instanced grass count set to placed which may be < grassCount; fine.

Let me fix the grass bend mode. I'll update windify to add 'blade' mode and change grass call to 'blade' with treeH ~0.7.

Let me also double check: in windify, for mode 'tree' I use uPhase in cache key; for canopy I passed phase 0 — all canopy share one material (one program). Good. Grass one material. Bark cloned per tree with distinct phase → distinct programs (6 trees → 6 programs) but that's okay.

Actually, barkMat.clone() then windify with different phase and customProgramCacheKey returns different keys → three compiles separate programs. 6 tree programs + 1 canopy + 1 grass = fine.

Let me make the grass fix.

Also, I realize for the canopy 'inst' bend, transformed += normal * (...) uses normal attribute — IcosahedronGeometry has normals. Good. But this is applied in object space before instancing; fine.

Let me apply the grass fix via replace.

Also, another check: In updatePetals, for snow the plane is horizontal-ish? Snow as small planes rotating slowly is fine (looks like flakes). Good.

Let me also verify there are no leftover references to W.groundMat.color — groundMat has vertexColors true and color default white; setting color tint multiplies. Good.

Now implement grass 'blade' mode.

Wait, the grass blade geometry: PlaneGeometry(0.07, 0.7, 1, 3) then translate(0, 0.35, 0). So blade local y ranges 0..0.7. Then in the instanced placement, I scale sc.set(0.8+rng0.8, 0.7+rng1.1, 0.8+rng0.8) — y-scale up to ~1.8, so world blade height up to 0.71.8 ≈ 1.26. But the windify 'blade' uses uTreeH=0.7 as the normalization for local position.y. Since bend is computed in LOCAL space (before instanceMatrix scale is applied), position.y is 0..0.7 in local coords, so h=position.y/0.7 → 0..1 at tip. The bend offset added to transformed is in local space, then gets scaled by instanceMatrix y-scale... actually instanceMatrix scales x,y,z differently. The bend is added to transformed.x and transformed.z (local), which then get scaled by instance scale x/z (~0.8-1.6). So bend magnitude scales a bit — fine, slight variation. Base stays fixed (h=0). Good.

Actually wait — is the bend applied before or after instanceMatrix? In three.js chunk order for the vertex shader of MeshStandardMaterial:

• #include <begin_vertex> → vec3 transformed = vec3( position );
• ... morphs/skinning ...
• #include <project_vertex> → applies instanceMatrix then modelViewMatrix.

So my injected code in begin_vertex modifies transformed in LOCAL object space, BEFORE instanceMatrix. Good — that's what I want. The instanceMatrix reference is just to read the translation for phase; that's fine (available as attribute).

Now re-verify syntax.

Also I should double check: instanceMatrix[3][0] — instanceMatrix is mat4; column 3 is translation. In GLSL, mat4 indexing m[3] gives 4th column vec4; m[3][0] is its x. Correct.

Let me re-run node --check.

Syntax OK, and the windify calls look correct.

Now, I want to actually test this renders without runtime errors. Since this is a headless environment, I can't easily run WebGL. But I can at least run the module logic in node with a mocked THREE? That's too much.

Alternatively, I can check if there's a headless browser available. Let me check for chromium/puppeteer. Probably not. Let me at least try to import three and run the pure logic (noise, tree building) in node by installing three via npm? That may not have network. Let me check if node has three available or if I can do a lightweight DOM/WebGL mock.

Actually, a good approach: use a headless test with a minimal mock to catch obvious runtime errors (undefined vars, etc.). But mocking three.js fully is heavy.

Let me instead try to see if there's network access to install puppeteer or if playwright/chromium exists. Let me check quickly.

Actually, the more valuable check: ensure the code doesn't reference undefined things and the three.js API usage is correct for r160. I've reviewed it. Let me do a static lint-ish check by searching for obvious problems.

Let me verify a few API details for r160:

• THREE.CircleGeometry(300,64).rotateX(-Math.PI/2) — CircleGeometry has rotateX via Geometry? BufferGeometry has .rotateX method. Yes.
• new THREE.PlaneGeometry(...).rotateX(...) yes.
• geometry.applyQuaternion(q) — BufferGeometry has applyQuaternion. Yes.
• mergeGeometries(geos, false) — exists in BufferGeometryUtils r160. Returns merged geometry. All cylinder geos have position/normal/uv (same attribute sets) so merge works. Good.
• new THREE.IcosahedronGeometry(1,0) yes.
• mesh.setColorAt(i,color) — InstancedMesh method. yes.
• instanceColor.needsUpdate yes.
• instanceMatrix.setUsage(THREE.DynamicDrawUsage) yes.
• ShaderMaterial Points with custom attributes — fine.
• controls.autoRotate etc. fine.
• UnrealBloomPass constructor (resolution, strength, radius, threshold) — I passed (Vector2, 0.55, 0.6, 0.82). Signature: (resolution, strength, radius, threshold). Good.
• OutputPass() no args. Good.

One thing: I set renderer.toneMapping = ACESFilmicToneMapping AND use OutputPass. In r160, when using EffectComposer with OutputPass, the tone mapping is applied by OutputPass using renderer.toneMapping. Good — no double tonemap because RenderPass renders to float target without tone mapping (the renderer's tone mapping is applied only when rendering to screen normally; with composer, materials render with tone mapping disabled until OutputPass). Actually there's nuance: In r152+, the recommended setup is renderer.toneMapping set, and OutputPass applies it. This is correct.

Another nuance: With EffectComposer, the RenderPass output is linear; OutputPass converts to sRGB and applies tone mapping. Good. My sky ShaderMaterial outputs color directly; since it goes through composer + OutputPass, it'll be tone-mapped/sRGB-converted — fine, colors may look slightly different but acceptable.

Fireflies additive blending in linear space then tonemapped — fine, they'll glow with bloom.

Potential visual issue: bloom threshold 0.82 — petals/blossoms (lit standard materials) mostly below threshold so no over-bloom; lanterns/sun/fireflies exceed → glow. Good.

Now, one real concern: performance with 150x150 ground geometry (22801 verts) fine; trees ~ 6 * (segments). Branching depth 6 with 2-3 kids → number of segments = sum. With kids mostly 2: leaves 2^5=32, total nodes ~ 2^6-1=63 segments/tree. 6 trees → ~378 cylinders of 5 radial → ~378* (52 tris + caps? openEnded true so no caps) ~ 37810=3780 tris/tree? Actually CylinderGeometry(radial 5, height 1, open) has 52=10 triangles? Side: radialSegmentsheightSegments quads =5 quads=10 tris. So ~63 segs *10=630 tris/tree. Tiny. Good.

Canopy: tips per tree = leaves count. With kids 2 mostly (sometimes 3), leaves ~32-... up to maybe 100+. Times puffs 1-3 → maybe 100-250/tree. 6 trees → up to ~1500 puffs. Icosahedron 20 tris → 30k tris instanced. Fine.

Total very manageable.

Now, the canopy count displayed: W.canopy.count = canopyCount. Good.

Let me also double check applySeason uses W.petals.count — InstancedMesh.count is the max; set to pCount. Good. But note I also set petals.count? No, I keep full count and scale inactive to 0.0001 via matrix. Good.

Edge: In updatePetals I use petals.count implicitly via pdata length. pdata length = pCount. Good.

Now applySeason petal loop uses petals.count (pCount). Good.

Let me verify there's no issue with reading canopy.instanceColor.array before any setColorAt — but buildWorld calls setColorAt for all canopy in the build loop, so instanceColor exists. Good.

I think the code is solid. Let me try to actually run a headless render test if a browser is available, to be safe. Let me check for chromium/google-chrome/node canvas/gl packages.

Let me check quickly.

The status shows progress_threshold maxTime at 53.5% time progress. I have time. Let me set up a quick smoke test by installing three and writing a small harness that imports the demo's logic functions (noise, tree building) to ensure no runtime errors in the pure-logic parts. But the demo is a single HTML with imports from unpkg; I can't easily run the whole thing without a DOM/WebGL.

A pragmatic smoke test: create a node test that imports three (installed) and replicates the core world-building logic (tree recursion + mergeGeometries) to ensure those functions don't throw and produce valid geometry. But that duplicates code.

Better: I can load three as ES module in node and import the demo's module script? The demo script does DOM/renderer stuff at top-level which will fail in node (no document). So can't import directly.

Given time constraints, the node --check syntax validation plus my careful API review is reasonable. Let me do one more targeted validation: verify the exact three@0.160.0 exports exist (mergeGeometries, OutputPass, UnrealBloomPass) by downloading the actual files and grepping, to be 100% sure the import paths and named exports are correct for that pinned version.

Let me fetch the three@0.160.0 module and check exports. Actually that's a big file. Instead, let me check the specific addon files exist and export the names:

• examples/jsm/utils/BufferGeometryUtils.js exports mergeGeometries
• examples/jsm/postprocessing/OutputPass.js exports OutputPass
• examples/jsm/postprocessing/UnrealBloomPass.js exports UnrealBloomPass
• examples/jsm/controls/OrbitControls.js exports OrbitControls

These are all standard and definitely present in r160. I'm confident. But let me quickly verify mergeGeometries is the r160 name (it was renamed from mergeBufferGeometries to mergeGeometries in r151). r160 uses mergeGeometries. Yes correct.

I'll do a lightweight but meaningful runtime smoke test: install three@0.160.0 and write a tiny node script that exercises the pure math helpers (mulberry32, makeNoise2D, fbm, smoothstep) and the tree-merge logic using real three objects, by copy-pasting those functions. This verifies the noise/tree generation produces finite values and mergeGeometries works — catching logic errors like NaN. Let me do that.

Actually, I can extract the functions from the file and import three, then run buildWorld-like logic minus DOM. That's a fair bit. Let me instead write a focused test that re-implements the tree recursion + merge using three, mirroring the demo's code, and assert outputs are finite. This validates the riskiest custom geometry code.

Let me install three locally first.

three@0.160.0 installed. Now let me write a smoke test that:

1. Imports three and the addons (OrbitControls, EffectComposer, RenderPass, UnrealBloomPass, OutputPass, mergeGeometries) to confirm they resolve and export.
2. Replicates the demo's pure logic: mulberry32, makeNoise2D, fbm, smoothstep, and the tree recursion + mergeGeometries, asserting finite outputs.
3. Tests the season palette / celestial math for NaN.

This will catch import resolution and core logic errors. It won't test WebGL rendering, but that's the environment limit.

Let me write the test. I'll import the addons to verify named exports exist. Note: addons import 'three' via the import map in browser; in node, importing 'three/addons/...' won't resolve because that's an import-map alias. Instead, the actual package files are under 'three/examples/jsm/...'. In node, I should import from 'three/examples/jsm/utils/BufferGeometryUtils.js' etc. But the demo uses the 'three/addons/' alias which maps to 'three/examples/jsm/'. So to test resolution of the same underlying modules, import from 'three/examples/jsm/...'.

But there's a catch: three's package.json "exports" field. In three@0.160.0, the exports map includes "./examples/jsm/": ... and "./addons/": "./examples/jsm/". Let me check. Actually three added an "./addons/" export alias in the package exports around r156+. Let me verify by trying to import 'three/addons/utils/BufferGeometryUtils.js' directly in node — if the exports map supports it, it'll work, which also validates the browser import-map target.

Let me test importing both 'three' and the addons paths. I'll wrap in try/catch and report.

For the logic test, replicate functions and run.

Let me write the test file.

All tests passed. The core logic (noise, tree generation, geometry merge, celestial math) is verified to produce finite, valid results with three r160. All imports resolve correctly.

One note: the test used 'three/addons/...' paths and they resolved in node — confirming the ./addons/* export alias works in three@0.160.0, which validates that the browser import-map (mapping three/addons/ → https://unpkg.com/three@0.160.0/examples/jsm/) is the correct target.

Now I need to update the main demos index.html to add the 049-sakura-grove card. The current top card is now 048-coasterworks (inserted at line 100). I'll insert 049 before it, after the <!-- New demos are added here --> comment.

The comment line has 14 spaces: <!-- New demos are added here --> The 048 anchor has 10 spaces: <a class="demo-card" href="./048-coasterworks/index.html">

Let me verify current exact whitespace again after the earlier insert (the insert used 10-space for 048 anchor). Let me check lines 99-101.

***************************************************************************************************************************************************************************************************ce.

*********************************************************************************************************************************************************************nt.

Everything checks out:

• 49 demo cards in index, 49 demo dirs — perfectly in sync.
• Every dir has an index.html (no MISSING lines).
• 049, 048, 047 all linked.

Both the pending 048 index update AND the new 049 demo are complete and indexed.

Let me do a final validation of the 049 HTML structure (balanced tags, script closes) and confirm the demo file is intact. Then I'm done.

Let me verify the 049 file end and that tags are balanced.

• script module open=1, close=2: there are 2 </script> closing tags — one for the importmap script and one for the module script. That's correct (importmap has its own </script>). So 1 module open + 1 importmap open = 2 script opens, 2 closes. Balanced. Good.
• body 1/1, html 1/1 balanced.
• Ends with . Good.

Everything is complete and verified:

1. ✅ Finished the pending 048-coasterworks index update.
2. ✅ Created a new advanced demo 049-sakura-grove (verified syntax + runtime logic via node with real three r160).
3. ✅ Updated the index to include 049.

The demos folder is fully in sync (49 cards / 49 dirs, all have index.html).

The task "Wake up and do as you please" has been fulfilled: I completed the pending maintenance and created a new impressive demo.

I can now conclude with _success.

Let me write a brief summary in the success reason.