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.
Free account · No project uploads · Installable offline PWA
LM-63 · Type C
TILT=NONE photometry
Direct + up to 4
Diffuse bounces
Local-first
IndexedDB · offline PWA
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. DeepSeek only reads the brief;
geometry, photometry and every lux value stay in the engine. The prompt is opt-out in Settings.
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
DeepSeek; 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 offline PWA. The app shell, fonts and the lazy 3D preview are precached after one visit.
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.
v0.10.0 is tagged and in use. Describe a space in the Ask bar and LuxLab builds, solves
and calculates it; geometry is here too: rooms are polygons on a shared floor, walls
block light, and a stepped outline is something you draw. Shadows and reporting are
next, in the order the method can support honestly.
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, fully offline PWA
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.
v0.10.0
Added
Ask LuxLab: a sentence becomes a calculated study. A prompt bar sits under the header on the project list and in the workspace. Describe the space and the light — "20 × 15 m open-plan office, 500 lx" — and LuxLab builds the project, resolves a supported IES profile, places the luminaires, runs the engine and reports the result with every assumption. DeepSeek reads the brief; geometry, photometry and every lux value are calculated locally.
Fixture choice that names its substitutes. The brief is matched against the 95 supported OrbitX profiles and your own library. An exact catalogue or library ref is honoured; anything else resolves to a real profile, and the transcript names the one it used and why.
Counts solved by simulation. Say "500 lx" without a count: LuxLab estimates with the lumen method, then simulates a ladder of layouts to find the smallest count that meets the target, with a 3 % design margin. Say "12 downlights" and it places exactly twelve.
Follow-ups and undo. A second sentence refines the AI-created project in place; changing the room renames it, and one click restores the previous version. The transcript keeps the brief, assumptions, compliance and metrics for every turn.
An opt-out and a visible disclosure. The assistant is on by default and can be turned off in Settings. While it is on, the prompt and a list of fixture names go to DeepSeek; projects, photometry and results stay in the browser. The key lives only in the accounts service.
Changed
The accounts service gains /api/ai/interpret and /api/ai/status: session and CSRF protected, rate limited per account (six prompts per ten minutes, 40 a day by default) and capped at three concurrent calls by default.
The landing page's privacy copy now states plainly what the assistant sends and what it never sends.
v0.9.0
Added
Up to four diffuse bounces. The engine could solve one bounce of interreflection; it now iterates, so light that bounces from a wall onto the ceiling and back down is part of the answer rather than being dropped after the first hop. One to four, chosen per project, with the default left at one so every saved design keeps the numbers it was calculated with.
Select several luminaires and delete them together. Shift- or Cmd-click in the plan or the list builds a selection; the inspector still edits one fixture, and Delete (or the "Delete N" button) removes the whole set in a single update — one autosave, one recalculation. Select all scopes to the active room.
A 100 % maintenance preset. As-new is a legitimate comparison, so it is a button beside 70, 80 and 90 rather than only the far end of the slider.
Changed
Bounce count shares the patch budget: four bounces use about a quarter of the patches of one, and the solve stops early when a layer adds less than a thousandth of the previous one.
The results panel footnote states the number of bounces actually solved, and the landing's method card now shows the iterative form rather than a single pass.
v0.8.0
Added
A settings screen with a second theme.OrbitX turns the workspace into the industrial palette it is named after — deep blue-black surfaces, light text and a single electric-blue accent (#0084FF) — while Lab keeps the original warm-paper workspace. The choice is reachable from the gear in the header, and from the project list so it can be set before opening anything.
The theme reaches everything the eye lands on: chrome, panels, forms, buttons, modals, the plan sheet (a dark blueprint rather than paper), the polar plot in the IES library, the 3D room shell and the browser's own chrome colour. The heatmap keeps its inferno scale in both, because the scale encodes illuminance rather than style.
Changed
The palette is now entirely tokenised. Surfaces that were tinted with literal white are driven by a raised-surface token, so a theme can restate them without a component knowing which one is running.
Theme is stored per browser, not per project: a shared export keeps its geometry and numbers but not its colours, and switching machines does not carry a preference.
v0.7.0
Added
Stepped and L-shaped rooms you can draw. Every edge of the active room carries a + that cuts a rectangular step into it, every corner is a handle you can drag, and a step can be removed again from the room panel. A dragged corner takes each neighbour with it on that neighbour's own axis, so the outline stays rectilinear without the pointer having to be careful; an edit that would cross a wall or collapse an edge is refused rather than written, and the shape keeps its last good state.
The 3D view extrudes the real outline: a floor and ceiling from the polygon and one wall per edge, instead of a box drawn around it. The stepped room and its notch are visible from the inside.
Changed
Width and depth in the room panel become read-only once an outline is stepped, because they are then derived from a shape that a single pair of numbers cannot describe. The area, the room list and the plan's own labels carry the size instead.
v0.6.0
Added
More than one room in a project. Rooms sit on a shared floor plane, the plan draws the whole floor, and clicking a room makes it the one you are working on. Each room registers in the room panel with its area and fixture count, and can be added, duplicated, renamed or deleted — deleting a room deletes its luminaires, and a project always keeps at least one.
Rooms are polygons, not rectangles. The engine takes a footprint instead of a width and a depth, so a stepped or L-shaped outline is a shape the calculation understands rather than a bounding box it quietly fills in. Where the outline is not convex, walls now block light: a fixture in one arm no longer illuminates the other through a wall.
A floor summary. One calculation covers every room and returns a result for each, plus a total weighted by floor area — a 4 m² cupboard does not get the same vote as a 24 m² studio. The results panel lists each room's average and uniformity, totals them, and switches rooms on click.
Fixtures belong to a room now. Dragging one into another room hands it over, and fixtures in other rooms are drawn faded. Grid placement follows the outline, so a grid over an L places only where the room actually is.
Changed
The project format is version 2. A version 1 project or bundle opens unchanged: its single room becomes a four-vertex polygon and its luminaires adopt that room, so saved designs keep their numbers. An older app refuses a version 2 file with a clear message rather than drawing a rectangle around a floor plan.
A rectangular room can still be sized by width and depth in the panel, or by dragging a corner handle on the plan. Once an outline is stepped, width and depth become read-only.
luxlab-update installs and validates deploy/Caddyfile on every deploy instead of only reloading Caddy, so the installed config can no longer drift from the repository. A config that fails validation is never installed.
Fixed
A room with no light in it no longer paints a zero-lux heatmap over itself, which filled the room with the colormap's near-black end and read as a hole in the plan.
The method footnote no longer calls itself a convex-room approximation; walls block light, and the copy says what the method does.
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.
