A floor plan that rolls into a house: casa-serra's 470 stars aren't from GitHub
What it is A 3D web demo: you open it to see an architectural floor plan, scroll down and the walls rise out of the drawing, and the camera moves into each room. The repo mostly holds the starter prompt used to build it.
Why it blew up "Floor plan rolls into a house" is clear in three seconds, and it landed right after Opus 5.5 launched. The author is a professional video editor who seeded videos on Threads, LinkedIn and YouTube first, then a second wave came when Meng To, a boss with 189k followers, reposted the link.
CHow you could follow Don't build another floor-plan-to-house. Find a different visual reversal where "the drawing is the finished product" in the same way, time it to the next model launch, test the reaction with short videos first, then build a repo with the demo, the prompt and a one-hour reproduction, and try to land one big-account repost.
- Data (updated daily) · Repo created 2026-10-13 · 474 stars · 7 days +172
GitHub · stars Data 2026-10-14 → 2026-11-08 (26 days, 26 observations). Points before 10-28 come from deeply / archive backfill, not every day has one
Samnang Aing built a web page with Claude Code and Opus 5.5: you open it to see an architectural floor plan, scroll down, and the walls grow out of the drawing while the camera moves into each room. In 24 days the repo got 470 stars and 107 forks, but nearly all those stars came from his videos on Threads, LinkedIn and YouTube, and the second wave came from a repost by his boss. Within three weeks people had copied the idea, and the copies got 0 stars.
Oct 12, "This has never happened to me before"
In Oct 2026 12, Samnang Aing posted on X: "This got over 60K views on Threads and LinkedIn combined overnight, which never happens to me. So here it is for X." He does video editing and creative development at Design+Code. The day before, he had posted a ten-second screen recording to Threads and LinkedIn: a black-line floor plan on white, labeled with room names and dimensions; scroll, the walls stand up, and the camera enters through the front door into the living room, the courtyard, and an olive tree. The LinkedIn post ended with 1,113 reactions and 153 comments, and the most common question in the comments was "how did you make it?"
The next day (10-13 UTC, early morning), he created the GitHub repo casa-serra and put a "starter prompt" right on the first screen of the README. Four days later the repo had 159 stars.
What it actually is
A landing page for a fictional Lisbon architecture studio, "Lintel," whose star is Casa Serra, a 946 m² courtyard house on the Sintra hills. The online demo is hosted on GitHub Pages.
The README explains the method: about 70 prompts, two weeks, four versions thrown out and rebuilt. The initial inspiration was a short video from an old game site, and the "floor plan" idea only came on day four. The stack is plain: three.js + GSAP ScrollTrigger + Lenis, plain files, no build step. All the geometry is generated in code, with no Blender. Textures are free CC0 scans from Poly Haven (about 39 MB on a laptop, about 13 MB on a phone, falling back to still frames and a recording on devices that can't run it).
What stops people is one line: The floor plan isn't an image. It's a real 3D model cut at 1.2 meters high and viewed from directly above with a very long lens. Scrolling down raises the cut plane, so it looks like the walls are growing. The drawing and the house are the same object, so the 2D-to-3D transition is continuous rather than "show an image, then cut to the model." Each room stays as line art until the camera reaches it, and then the materials sweep in.
One caveat: the code in the repo is minified and hard to read. What it really gives away is the prompt, plus a companion repo, casa-larga. The author used the prompt to start a brand-new session, and an hour later got the first checkpoint, with the code released as-is (now 31 stars, 18 forks).
How the stars grew
| Date | star | fork | What happened |
|---|---|---|---|
| 10-11/12 | — | — | Launched on Threads + LinkedIn, 60k views overnight; 10-12 posted to X |
| 10-13 | 0 | — | Repo created, README leads with the starter prompt |
| 10-17 | 159 | 39 | First wave |
| 10-21 | 251 | 68 | Making-of video on YouTube goes live during this stretch |
| 10-28 | 285 | 76 | Plateau, +1 to +5 per day |
| 11-03 | 304 | 81 | Meng To reposts with the repo link |
| 11-04 | 393 | 94 | +89 in a single day, the peak day |
| 11-05 | 445 | 99 | +52 |
| 11-06 | 470 | 107 | Past 7 days +165, the week before that only +33 |
Data: GitHub repo page and daily star records (since 10-17); on Trendshift's CSS category chart it hit #2 twice, dropping to #7–16 in between. It never made GitHub's sitewide trending.
Point by point.
Short videos first. It went out on Threads and LinkedIn first, then moved to X, Instagram (a 10-24 reel) and TikTok (an account with only 42 followers that barely contributed). Architecture, interiors, real estate and web design circles were all willing to share a three-second "floor plan becomes house" reversal.
Long YouTube video. "A lot of you asked how this was made, so I made a video about it": "Opus 5.5 Turned a Flat Floor Plan Into a Walkable 3D House", about 158k views. The author edits video for a living, so the pacing and title are professional.
Boss repost. Nov 3, Meng To (founder of Design+Code and Aura.build, about 189k followers on X) posted: "novel way to mix architecture, web design and 3d. opus 5.5 is a beast with three.js. prompt: github.com/Sam1983Aing/casa-serra". The author's X bio reads "@ Design+Code," meaning his own boss reposted it. The post linked the GitHub repo directly, and in two days it added 11-04 and 11-05 stars, 141 stars in total. That was the entire source of the second wave.
The author did none of the later spreading. opuskill.com turned its prompt into a tutorial page; tripo3d's prompt library, the WO! Discover newsletter and various "awesome-opus-5.5" lists picked it up; AI traffic accounts on Instagram made posts of "Claude turns a floor plan into a walkable 3D house" with "comment CLAUDE for 7 prompts." I found no trace of ads or a launch on Hacker News or Reddit.
The fork-to-star ratio is about 23%, clearly high. The reason is simple: it's a Pages demo, and forking it gives you your own live address to edit, and the original post invited people to take the prompt and make their own. So most of the people starring it are bookmarking a prompt and copying a method, not using a library.
Why this one
- Instantly understood. "Looks like a drawing, rolls into a house," no explanation needed. The autoplaying three seconds say it all.
- Timed to the Opus 5.5 launch. Every post said "Built with Claude Opus 5.5," and in those weeks everyone was looking for "what can the new model make that looks good?" This was a showcase. Meng To's repost also praised the model.
- The author can make videos and has connections. The first wave came from his own video seeding across five platforms, the second from a boss with 189k followers. Anyone who only copies the prompt gets neither.
Who it's competing with
| Project | Launched | Scale | How it differs |
|---|---|---|---|
| Matterport and developers' 3D unit walkthrough services | Years ago | Commercial services with published quotes starting at $1,495 per unit | Real-world / floor plan walkthrough tools; casa-serra borrows a marketing-page narrative technique |
| cvdlab/react-planner | 2016 | 1,490 stars | Floor plan editors that cut to 3D views, with no scroll storytelling |
| Home Assistant 3D floor plans (ha-floorplan, neonplan3d) | 2017 / 2026-09 | 1,738 / 1,056 stars | Smart home dashboards, practical utilities |
| fireship-io/threejs-scroll-animation-demo | 2021 | 1,673 stars | Generic three.js scroll tutorials |
| Moh4696/open-3d-skills | 10-31 | 269 stars (6 days) | 3D web skill packs for Claude Code / Codex; these are tools |
The real peers, "AI-made 3D scroll pages," are almost all small repos with a few stars; the ones with many stars are either established tools or, like open-3d-skills, packaged "how to get an agent to build a 3D web page" into something others can install directly.
What the copiers got
The author then released sequels: flat-to-3d (10-28, "seven ways to turn a floor plan into a scrolling 3D page," each with a prompt, 68 stars), the full lintel, and casa-larga.
Outsiders followed quickly: mys1erious/3d-plan-to-walk (11-03, a Palladian rotunda villa, whose description reads word for word "cut 1.2 m above the floor"), and wilsonwu-ai/floor-plan-to-house (11-04, "A floor plan that becomes a 3D house as you scroll"), plus several similar repos, all at 11-06 to 0 stars. On Instagram someone made a series called "Boring to Game Ep 1" whose opening line is "The idea was first shown by Sam Aing"; on YouTube there's "Floor Plan to 3D House With Claude Code (Free Master Prompt)," with under 3,000 views.
Two things follow: the idea can be copied from one prompt (the author himself showed with casa-larga that a first version can come out in an hour), so it can't be defended; and the people who copied the idea don't get stars, because stars were never given by GitHub itself. They came from the videos and reposts.
If it were you
Verdict: Don't build "floor plan scrolls into a house" again. The visual has already been used up by the author and AI traffic accounts, and the copycat repos all have 0 stars. What's worth learning is how it was launched: test the reaction with a video first, and only build the repo with the prompt once the comments are asking "how did you make it?"
Who it suits: Front-end or three.js developers who can edit video and already have a small audience on LinkedIn, Threads or X; people who know a visual industry (architecture, product design, cars, watches, museums) and can come up with a "visual reversal you can explain in one sentence."
Who it doesn't suit: People who only want to write code and won't appear on camera or edit video; people hoping a demo on GitHub will bring in organic traffic on its own; people who want to swap in a different house and redo the same effect.
How to do it: Find an idea at the same level as "the floor plan is a cut model": the drawing and the finished product are the same object, and they transform as you scroll. Exploded diagrams roll into a camera, a music score rolls into a band, a subway map rolls into a city, a cutting-layout sheet rolls into a chair. Build it with a new model and iterate until the texture passes (the author spent two weeks and 70 prompts). The repo should contain three things: the live demo, the starter prompt, and a "version produced in one hour from only this prompt" as proof. You don't have to release the code; the stars still come.
How to get users: Post 10–15 second vertical screen recordings on Threads and LinkedIn, titled "Built with <new model name>". If one takes off overnight, repost to X and Instagram, add a YouTube build-process video, and link the repo everywhere. Also get someone with reach (a peer, a model vendor's ecosystem account, a big design account) to repost the repo link once. Half of casa-serra's stars came from one repost.
When is the window: Two to three weeks after the next major model launch. People most want to share "what it can build" when a model is new. After that window, the same work is just another three.js demo.
What would prove this read wrong: ① Someone gets a similar 3D scroll page to a few hundred stars with GitHub alone (no video, no big repost). That would mean GitHub has organic traffic of its own, and the bar is lower than I think. ② Copycat "floor plan becomes house" repos reach hundreds of stars. That would mean this specific idea isn't exhausted yet. ③ After the next model launches, "Built with new model" visual demos generally fail to get traction. That would mean the novelty has worn off.
Data and sources: GitHub repo page, README and daily star history (10-17 to 11-06); trendshift.io/repositories/302292; author's X post (x.com/SammmAing, 10-12); original LinkedIn post (reactions and comments, 11-06); YouTube "Opus 5.5 Turned a Flat Floor Plan Into a Walkable 3D House"; Meng To's X post (11-03); Instagram reel (10-24); opuskill.com, tripo3d and WO! Discover W42 listing pages; GitHub pages of copycat repos (11-06). We can't separate how many stars each channel brought. We didn't get the Threads post data or the view count on Meng To's repost.
Research notes: competitor table, acquisition evidence, full research report
- Competitors
Name Where Launched Scale How it differs from this one Matterport and builder 3D floor plan tour services Other Years ago Commercial service, public pricing from $1,495 per floor plan (cited by Substack) Those are real-space or floor plan walkthrough tools and services. casa-serra is a scroll-narrative technique on a marketing landing page, free, and reproducible from a prompt. cvdlab/react-planner Open source 2016 1,490 stars Editor that draws a 2D floor plan and switches to 3D to browse. No scroll narrative, and no continuous 2D-to-3D morph. Home Assistant 3D floor plans (neonplan3d / ha-floorplan) Open source 2017 / 2026-09 1,738 / 1,056 stars Smart home control panels, practical tools, not showcase pages fireship-io/threejs-scroll-animation-demo Open source 2021 1,673 stars Generic three.js scroll portfolio tutorial. No architecture concept, not AI-generated. Moh4696/open-3d-skills Open source 2026-10-31 262 stars A 3D web skill pack for agents. It's a tool. casa-serra is a single viral visual sample. Leonxlnx/realestateopus5 Open source 2026-07 7 stars Also a real-estate scroll piece made with Opus, but without the "the floor plan is the model" twist, and nobody distributed it. - Where users come from
- Verified Threads + LinkedIn short-video launch: author X 10-12: "over 60K views on Threads and LinkedIn combined overnight"; the original LinkedIn post has 1,113 reactions and 153 comments
- Verified Author's X post: x.com/SammmAing/status/2109708195031900310 (10-12)
- Verified YouTube build-process long video: the author's channel, "Opus 5.5 Turned a Flat Floor Plan Into a Walkable 3D House", 158,618 views. The README and flat-to-3d both link back.
- Verified Big-account repost (the author's boss): Meng To (founder of Design+Code / Aura, ~189k followers on X) reposted with the GitHub link at 11-03 02:40 UTC. Next day +89, the day after +52.
- Verified Instagram / TikTok reel: Instagram samnang.aing 10-24 reel; TikTok @samnang_aing (42 followers, small contribution)
- Verified Content farm and aggregator reposts: opuskill.com tutorial page, tripo3d prompt library, WO! Discover W42, nicheloom, githubsignals, Myth & Machine Shorts
- Verified Trendshift category chart: twice reached #2 in the CSS category, a result that also carried some long-tail traffic.
Sam1983Aing/casa-serra: why a "floor plan rolls into a house" demo got 460 stars
Research date 2026-11-06. Data: our GitHub repo library (repo_day since 10-28), data cards, GitHub API, Jina search and page text.
One line
It's a scroll-driven 3D web piece built by Samnang Aing (a Design+Code video editor / creative developer) with Claude Code + Opus 5.5. The page opens on an architectural floor plan. As you scroll, walls rise out of the drawing and the camera moves through each room. The GitHub repo is just a landing page. The stars came from short videos he posted on Threads / LinkedIn / X / YouTube / Instagram / TikTok. The second wave came straight from his boss Meng To (189K followers on X) 11-03 reposting it.
1. What it is
- Repo: github.com/Sam1983Aing/casa-serra. Live demo: sam1983aing.github.io/casa-serra/
- A landing page for a fictional Lisbon architecture studio, "Lintel". The house is Casa Serra (a 946 m² courtyard house on the Sintra hills, 16 rooms and one olive tree).
- How it was made (README): about 70 prompts over two weeks, 4 complete versions. three.js + GSAP ScrollTrigger + Lenis, no build step. All geometry is code-generated, no Blender. Textures are CC0 scans from Poly Haven (about 39 MB on laptop, about 13 MB on mobile). The release ships the compressed code.
- Core trick: "The floor plan isn't an image, it's a real 3D model sliced at 1.2 m and viewed from directly above with a telephoto lens." Scrolling raises the slice height, so it looks like the walls are growing. Rooms you haven't reached stay as line drawings. The camera sweeps over materials only once it arrives.
- The README includes a starter prompt (starter-prompt.md), plus a comparison repo, casa-larga. In a new session using only this prompt, the first checkpoint took an hour (31 stars / 18 forks).
2. Data
| Date | star | fork | Notes |
|---|---|---|---|
| 10-13 | 0 | – | Repo created 02:27 UTC, after the social posts went out |
| 10-17 | 159 | 39 | First wave (data card daily) |
| 10-21 | 251 | 68 | |
| 10-28 | 285 | 76 | Plateau, 1–5 stars per day |
| 11-03 | 304 | 81 | |
| 11-04 | 393 | 94 | +89, daily high |
| 11-05 | 445 | 99 | +52 |
| 11-06 | 461 | 104 | gain_7d=165, previous week 33 |
- Trendshift CSS category chart: reached #2 twice (once mid-October, once early November), and dropped to #7–16 in between (https://trendshift.io/repositories/302292).
- Fork/star ratio about 23%, clearly high. It's a GitHub Pages demo, so anyone can fork it and point their own Pages URL at it. The original post also invites people to "take the prompt and make your own".
- Did not enter GitHub's site-wide trending (trending_days_any=0, and the repo wasn't 60 days old yet).
3. Where users came from (growth tactics)
The timeline mostly lines up. It was all the author's own distribution, plus one high-impact repost.
- Threads + LinkedIn first (about 10-11/12). The author 10-12 wrote on X: "This got over 60K views on Threads and LinkedIn combined overnight, which never happens to me. So here it is for X." (https://x.com/SammmAing/status/2109708195031900310, 2026-10-12 18:10 UTC). The original LinkedIn post got 1,113 reactions and 153 comments (https://www.linkedin.com/posts/samnang-aing-639168341_im-exploring-a-new-way-to-use-3d-on-a-web-activity-7515242371945783298-xdsP).
- Created the GitHub repo to catch traffic (10-13): created after the post took off and people in the comments were asking "how did you make this". The README centers on the "starter prompt". First week 0→159 stars.
- YouTube long-form "how it's made": "Opus 5.5 Turned a Flat Floor Plan Into a Walkable 3D House", on the author's channel, published about 3 weeks earlier, 158,618 views (https://www.youtube.com/watch?v=rKv4PrtBkb8). The author's X post says "A lot of you asked how this was made, so I made a video about it".
- Instagram / TikTok short videos: Instagram reel 10-24 (https://www.instagram.com/reel/De4c2KUSf9c/). TikTok @samnang_aing also posted, but the account has only 42 followers, so it contributed little.
- Meng To repost (11-03 02:40 UTC): "novel way to mix architecture, web design and 3d. opus 5.5 is a beast with three.js. prompt: github.com/Sam1983Aing/casa-serra" (https://x.com/MengTo/status/2117446870033445104). Meng To is the founder of Design+Code and Aura.build, with about 189k followers on X. The author's X bio reads "@ Design+Code", so the repost came from his own boss. The repost linked directly to the GitHub repo, so the day it went out saw +11-04 89 and 11-05 +52. That's how the second wave arrived.
- Secondary spread / content farm pickup (the author did nothing): Myth & Machine's YouTube Short (10-20,1.2K views); opuskill.com turned the prompt into a tutorial page; tripo3d.ai's prompt library; WO! Discover 2026-W42 newsletter, nicheloom, githubsignals and others picked it up; awesome-opus-5.5-style lists. Separately, the "Claude turns a floor plan into a walkable 3D house" topic was already turned into lead-gen posts on Instagram by AI accounts like godofprompt ("Comment CLAUDE for 7 prompts"). A Substack post, "Mother Using AI" 10-17, mentioned "one post like this got 303k views and 5,600 saves in three days." These don't necessarily refer to the author, but they show the topic itself spread widely.
No evidence found of ads, or of a Hacker News or Reddit launch. x-radar's local corpus has no related tweets (the library doesn't cover it).
4. Why it took off
- An instant visual twist: "looks like a floor plan, scroll and it becomes a house". The whole idea lands in a 3-second short video, which suits autoplay on Threads, LinkedIn and Reels. Architecture, interiors, real estate and design circles all want to share it.
- Riding the Opus 5.5 launch wave: every post says "Built with Claude Opus 5.5", and Meng To's repost says "opus 5.5 is a beast with three.js". A new model just dropped, and everyone is looking for samples of what it can build. This one is a good-looking sample.
- GitHub as a place to pick up prompts: the repo has no readable source (it's minified). What it actually gives you is a starter prompt plus a reproducible casa-larga. People star and fork it because they want to save the prompt or copy the approach, not because they want to use the library.
- The author knows video: he's a video editor by trade, so the screen recordings, pacing, and titles are professional. He also built the demo early with a fallback: static frames and screen recordings when the device can't run it.
- Borrowed reach: the second wave came entirely from Meng To's repost. The author works at Design+Code, and this repost was an in-circle resource, not pure organic traffic.
5. Competitors and similar apps
- Products doing the same thing as a business: Matterport-style real-estate 3D walkthroughs, services that build 3D floor-plan tours for developers (a Substack writer found public quotes of $1,495 and up per unit), Walkable Plans-style 1:1 floor-plan projections, and AI floor-plan generators like Ideal House. They are tools and services. casa-serra is a storytelling device on a marketing landing page; the two are not the same thing.
- Open-source floor-plan editors: cvdlab/react-planner (1,490 stars, 2016), Home Assistant 3D floor plans (neonplan3d 1,056 stars, ha-floorplan 1,738 stars), openPlan3D (272 stars), egmalt/house-planner (372 stars). These are tools for drawing and viewing floor plans. None of them do scroll-driven storytelling.
- Scroll-driven 3D web demos: fireship-io/threejs-scroll-animation-demo (1,673 stars, 2021), Leonxlnx/realestateopus5 (7 stars, a real-estate scroll film), Moh4696/open-3d-skills (262 stars, 10-31 built, 3D web skills for agents). They are also "AI builds 3D web pages", but none of them have the idea that the floor plan is the sectioned model.
- Big-company features: no direct equivalent.
6. Copycats
- The author's own follow-ups: flat-to-3d (67 stars, 10-28 built, "seven ways to turn a floor plan into a scrolling 3D", each with a prompt), lintel-flat-2d / lintel-live (v10 full version), casa-larga. Note: the data card's "67-star copycat repo" is actually the author's own work, not an outsider's.
- Copycats: mys1erious/3d-plan-to-walk (11-03, Palladian villa rotunda, the description literally says "cut 1.2 m above the floor"), wilsonwu-ai/floor-plan-to-house (11-04, "A floor plan that becomes a 3D house as you scroll"), Michaelfun/meridalDesign, jplovensa/veil-of-light and others, all sitting at 0–1 stars; Instagram quietbuilder88 "Boring to Game Ep 1" (10-17) openly says "The idea was first shown by Sam Aing"; on YouTube, MaxDevAi's "Floor Plan to 3D House With Claude Code (Free Master Prompt)" (2,966 views).
- The topic has already been taken up by AI engagement accounts (godofprompt's "7 prompts" post).
7. Differentiation, and whether that's why it broke out
There is only one differentiator, and it is a concept: "the floor plan is a sectioned real model." 2D to 3D is one continuous object, while others usually paste in an image and then cut to a model. Add "each room starts as line work and gets materials only when you walk in," and it has a strong architectural flavor. That single point is why it spreads: the visual reversal depends on it. But the concept can be reproduced with one prompt (the author himself showed a first version in an hour with casa-larga), and outsiders copied an identical description within 3 weeks. So this differentiator drove the spread but can't be defended. What's hard to copy is the texture the author polished over 70 iterations across two weeks, and his distribution channels (LinkedIn, YouTube at 150k views, plus his boss's repost).
8. What to borrow
- Social-first launch, GitHub catches the traffic: first post short videos on Threads / LinkedIn, and once the "how was this made" comments pile up, create the repo and publish the prompt. The repo's value is the prompt plus reproducible proof (casa-larga), not the source code.
- Turn one visual concept into a series: after one hit, keep releasing "seven approaches", a v10 full version, and tutorial videos, each linking back to the original repo.
- Ride a new model's launch window: "Built with <new model>" makes model vendors' ecosystem accounts and AI content accounts willing to repost.
- Get a peer or boss with an audience to repost once, and the second wave arrives.
9. Still unclear
- The exact numbers for the original Threads post were not obtained. Who posted the Substack's "303k views, 5,600 saves" post is unverified.
- The view count for Meng To's repost was not obtained (x-radar doesn't index it).
- It's impossible to tell how many stars came from YouTube, LinkedIn, and X respectively in the first wave.
- No direct evidence found on whether the author is using this to win client work or sell courses (Design+Code sells courses).