A local-first IES lighting simulator for the browser: import real photometry, model a room, aim your
luminaires, or just describe the space — and read the work plane as a heatmap with engineering metrics.
Direct light plus up to four diffuse bounces, calculated on your machine.
Plate 01 / PlanAtelier · 6.00 × 4.00 × 3.00 m · as new
Average
467 lx
Uniformity
23%
Target
79% ≥ 300 lx
Fig. 01 — Demo atelier: six 2,400 lm downlights, a 64 × 43 grid and 450 surface patches.
Mean 467 lx as new. At the default 0.80 maintenance factor the same
room reads 373 lx maintained.
01What it does
A lighting study, not a render.
Photometry, geometry and result stay visible and editable. No hidden defaults, no black-box solver.
01 / Input
Import real photometry
Drop in an LM-63 Type C file. The parser reads the angle tables, symmetry and candela, draws a polar
distribution, and surfaces the lumens, watts and maximum candela behind it.
LM-63 · Type C · TILT=NONE
02 / Model
Build the room, aim the light
Set a rectangular room, work-plane height and surface reflectances. Place luminaires by hand, or stamp a
block of them with grid placement, then tune mounting height, aim, tilt and dimming in the inspector.
X/Y · Mount · Aim · Tilt · Dim
03 / Result
Read the work plane
Switch between total, direct and reflected illuminance. Track average, minimum, maximum and uniformity,
check a target-lux threshold, and hover the grid for a point reading. Up to three labelled isolux
contours trace the levels that matter, and a maintenance factor turns as-new figures into the
maintained values you specify against.
Average · Min · Max · U0 · Target
04 / Ask
Describe it, then calculate it
Type the room and the light you want — "20 × 15 m office, 500 lx" — and LuxLab builds the
scene, sizes the layout by simulation and reports the result. With a project open, ask
why the result looks the way it does or request a small change; LuxLab applies it,
recalculates and shows before and after. The provider reads the brief or project summary;
geometry, photometry and every lux value stay in the engine. Administrators choose
DeepSeek or OpenCode Go and manage the encrypted key in Settings; each person can still
hide the bar in their own browser. Select several lights to move them together, and
export the whole study as a PDF plan, 3D view and results report.
A short loop: edit, debounce, calculate. The worker keeps the interface responsive while the grid runs.
01Parse
Import and validate
Open the IES library and load a Type C file. LuxLab checks the header and angle tables, expands symmetry,
and builds a bilinear candela sampler.
Rejects TILT=INCLUDE · Type A/B
02Model
Place and aim
Set the room and work plane, then place luminaires in plan. Use the inspector for mounting height, aim,
tilt and dimming. The 3D view is read-only.
Walls block light · No shadows yet
03Read
Calculate and inspect
Recompute and read the false-colour map. Compare total, direct and reflected views, then check the
metrics and the target threshold.
Direct + up to four bounces
03Local-first
The calculation never leaves the tab.
No project uploads and no server-side render. An account gates the tool; the geometry, photometry
and results stay in the tab. If you use Ask LuxLab, the sentence and a list of fixture names go to
the configured AI provider; turning the assistant off in Settings sends nothing. Projects and IES source text live in
IndexedDB, and the service worker keeps the tool available offline. Close the lid and the room is
still there.
Private by default
No project uploads and no tracking cookies. Your project stays browser state, not a
server record; page views are counted anonymously. The assistant is the one network
feature, and it is opt-out.
Instant feedback
The engine runs in a Web Worker. Edits debounce for 360 ms; only the latest calculation survives.
Install it and unplug
An installable PWA. The app shell and fonts are precached after one visit; a cold start still checks your session online.
Portable projects
Exports are self-contained .luxlab.json files with every referenced IES profile embedded.
IES→Parser→Worker→Canvas→IndexedDB
Plate 02 / 3D previewProjects stay in the browser
6 luminaires450 patches467 lx mean as new
Fig. 02 — Work-plane illuminance in the read-only 3D preview. Same 450 patches; rendered locally.
04The plan
Credible studies, at browser speed.
v0.17.1 is tagged and in use. Undo and Redo now cover the whole project: a light move, a
delete, a setting change and an assistant edit are each one step, and a drag undoes as a
whole. The public handbook lives at /wiki/, and the workspace has a Help menu, a shortcut
sheet and a status bar that names the current tool and calculation state. Deleting a room
asks first and tells you how many lights go with it. Draw a room with a rectangle drag or
an orthogonal outline, edit corners and walls with snapping, type exact wall lengths and
move a room with its lights. The Projects lobby remains an
OrbitX portfolio. Press Select in the luminaire list to choose lights explicitly, then move
or delete them together. Export a full A4 PDF with a 2D plan of every room, a 3D view, all
results and the schedules. Describe a space in the Ask bar and LuxLab builds, solves and
calculates it; with a project open, ask why the result looks the way it does or request a
small edit, with Undo behind it.
The goal
Make a credible IES illumination study as quick as opening a tab: fast enough to iterate, private enough
for client work, and accessible enough that photometry isn't locked inside desktop software.
Shipped now
Shipped
One or more rooms on a shared floor plan, each with its own ceiling
Polygon room outlines, with walls that block light
Stepped and L-shaped rooms you can draw and reshape
Two workspaces: warm paper, or the OrbitX dark palette
A floor summary, area-weighted across every room
Type C, TILT=NONE IES import with polar preview
OrbitX catalogue: 97 IES profiles across 20 families
Direct illuminance plus up to four diffuse bounces
Multi-select on the plan, to move or delete a group at once
2D plan editor and read-only 3D preview
Average, min, max, U0 and target compliance
Up to three labelled isolux contours
Maintenance factor: fixed, or the CIE 97 four-factor method
Grid placement for blocks of luminaires
Accounts with roles, an admin dashboard and first-run password change
IndexedDB projects with self-contained JSON export
Installable PWA with local projects
Next
Unscheduled
→Freeform outlines at any angle, and rooms that share a doorway
→Openings, furniture and shadow rays
→CSV and PDF report export
→Glare metrics, including UGR
→Type A/B photometry and TILT data
→Multi-bounce or path-traced verification
No dates. Scope follows what the method can support honestly.
05Method
A short, inspectable pipeline.
Parse, interpolate, integrate, display. Every result is reproducible from the inputs, in the browser.
01LM-63
02Bilinear
03Worker
04Typed arrays
05Canvas
06IndexedDB
01
LM-63 parser
Type C, TILT=NONE, header variants and symmetry expansion. Unsupported photometry is rejected, not approximated.
02
Bilinear candela
Vertical and horizontal interpolation with 360° wrap-around. Dimming and the maintenance factor scale candela linearly, per luminaire.
03
Web Worker
The pure engine runs off the main thread. Edits debounce for 360 ms and the latest request wins.
04
Deterministic heatmaps
The inferno scale is driven by the data's min and max. No random dithering, no per-frame noise.
05
Local IndexedDB
Projects and IES source text persist in the browser. Exports embed every referenced profile.
06
Offline PWA
The app shell, fonts and lazy 3D chunk are precached after the first visit. No CDN in the path.
Calculation
DirectE = I(γ, C) · cos ε / r²Up to four bouncesBᵢ¹ = ρᵢ · EᵢBᵢk+1 = ρᵢ · Σⱼ Bⱼk Aⱼ cos θⱼ cos θᵢ / (π rᵢⱼ²)Eref(p) = Σₖ Σᵢ Bᵢk Aᵢ cos θᵢ cos θₚ / (π rᵢ²)MaintainedEm = MF · (Ed + Eref), MF = LLMF · LSF · LMF · RSMF
Bilinear candela in γ and C. One bounce by default and up to four; still an estimate, not a full
radiosity solve.
Fixture check
750 lm declared→748 lm integrated
A public Cooper Lighting MRZ Type C profile was integrated at 1°. The check exercises angle handling and
flux integration — it is not a certification.
Third-party fixture · Not a compliance claim
06Changelog
What shipped, in order.
Generated from the project changelog on every deploy, so the page cannot fall behind the release.
v0.17.1
Added
Delete targets the active room. With no light selected on the plan, Delete or Backspace now opens the room-delete confirmation for the active room instead of doing nothing. Escape or Cancel leaves the room in place, and Undo restores it with its luminaires. With a light selected, Delete keeps targeting the lights.
Changed
The room-delete dialog now lives at app level, so the shortcut shows it even on a phone with the Room and lights drawer closed.
The light-delete dialog no longer claims the deletion cannot be undone; Undo restores the lights.
Notes
No schema, database, API or engine change. The guard still refuses to delete the last room.
scripts/smoke-room.mjs covers Delete, Escape, the confirmation and Undo; the store tests cover request, cancel, confirm, the last-room guard and a project switch.
v0.17.0
Added
Project-wide Undo/Redo. Every edit to the open project is one step in a single stack: a light move, aim, tilt, dimming, mounting height, name or profile; adding, duplicating, deleting and grid placement; drawing, adding, duplicating, deleting, renaming, moving and reshaping a room and its wall dimensions; the work plane, grid detail, target lux, reflectances, reflected light, bounces, maintenance factors and isoline levels; the project name; and an assistant edit batch. The plan rail names the step ("Undo Move 2 lights"), and Cmd/Ctrl+Z, Shift+Cmd/Ctrl+Z and Ctrl+Y work from both the plan and 3D views.
Continuous edits collapse into one step. A pointer drag, a slider or a typing burst merges inside a sliding 700 ms window, so Undo returns to the state before the drag instead of replaying pointer events.
Changed
Room-scoped history is replaced by one project stack of 50 steps. Light, environment and assistant edits no longer clear the room steps.
Switching, creating, duplicating or importing a project starts an empty stack; the history is in memory and is not restored after a reload.
The room-delete dialog now says Undo restores the room instead of warning that another edit ends the window.
The shortcut dialog and the handbook's Undo section describe the single stack instead of room-scoped history.
Notes
No schema, database, API or engine change. src/lib/history.ts is pure and unit-tested.
New smoke: scripts/smoke-undo.mjs.
This ships the project-wide undo that the 0.16.0 notes listed as a follow-up.
v0.16.0
Added
A public handbook at /wiki/. A new static page beside the landing page explains the workspace, rooms and the plan, luminaires and IES files, the calculation and metrics, reports, Ask LuxLab, accounts, the method and limits, troubleshooting and every keyboard shortcut. It is generated from docs/wiki/index.md, linked from the landing navigation and footer, and linked contextually from every workspace panel.
An in-app help layer. A Help menu and a keyboard-shortcut dialog, a mobile More menu, section-level handbook links, an About and help block in Settings and a guide link in the project lobby.
Mobile workspace improvements. The plan rail and view controls are compact on phones, the results are one tap away, the header keeps the save state visible and the canvas has more room.
A maintained documentation loop.npm run wiki:build renders the handbook, npm run wiki:check catches drift, and AGENTS.md requires the matching section to be updated in the same commit. npm run check includes the wiki check.
Changed
The status bar is now the contextual status line: it shows the current tool hint, the derived calculation method and a live calculation state, plus a link to the handbook.
The left panel is called Room & lights and its draw action is Draw rectangle.
Toasts no longer cover the results panel, the plan hint strip no longer competes with the room chip, and the mobile layout keeps the top controls clear.
Functional text in the touched surfaces is larger and load-bearing muted text uses the full palette token. Hard-coded amber and red classes in the plan chrome, selection bar, scene labels and account menu now use the theme tokens.
The landing, README and handbook describe the offline PWA accurately: the app shell loads offline, while a cold start still checks the session online.
Fixed
Add-luminaire search keeps focus. Modal now keeps its close callback in a ref and supports an explicit initial focus, so typing no longer moves focus to the close button.
A single light uses the same delete confirmation as a set, with the correct accessible name and a phone-sized target.
The calculation method label matches the project. "Direct + N bounces" (or "Direct only") is derived from the environment and the solved result instead of a fixed one-bounce string.
The room-scoped undo is labelled honestly, and the assistant's separate Undo is documented.
The account menu uses a real hover surface, a 44 px phone target and Escape to close.
The workspace gets a skip link, the plan gets a visible focus ring, the mobile drawers trap and restore focus, and reduced-motion preferences are respected.
Notes
No server API, database migration or project schema change.
The handbook is generated with the repository's small Markdown renderer; no new dependency is shipped to the browser.
Project-wide undo, cached offline access, workspace modes, a command palette and a project tree remain follow-ups. The audit records why.
scripts/smoke-help.mjs covers the Help and More menus, the shortcut dialog, add-dialog focus, the single-light delete and the 390 px layout.
v0.15.2
Fixed
Deleting a room asks first. The Room panel's delete was a single click that also removed every luminaire in the room. It now opens a confirmation that names the room, reports how many lights go with it, and says the study recalculates. Cancel leaves the room and its luminaires untouched. The dialog is bound to the room that was clicked, not to whichever room is active, so a change of selection cannot retarget it.
Notes
No schema, database, API or environment change.
Room-scoped Undo still restores a confirmed delete until a non-room edit clears the history, so the dialog says that instead of claiming the deletion is permanent.
scripts/smoke-room.mjs now covers the prompt, its Cancel path, the empty-room copy and Undo after a confirmed delete.
v0.15.1
Fixed
Fast room drags are reliable. The rectangle draft now lives in a ref while the pointer is down, so a quick press-move-release cannot finish against a stale zero-size draft. This is the same guard the outline draft already needed for rapid pointer events.
07Ready when you are
Start with a room. Leave with a number.
One click from the project list: 6 × 4 × 3 m, six 2,400 lm downlights, 373 lx maintained at the default
0.80 factor. A free account keeps it yours; nothing you draw is uploaded.
