A local-first IES lighting simulator for the browser: import real photometry, model a room, aim your
luminaires, and read the work plane as a heatmap with engineering metrics — direct light plus one diffuse
bounce, calculated on your machine.
Free account · No uploads · Installable offline PWA
LM-63 · Type C
TILT=NONE photometry
Direct + 1 bounce
Convex-room estimate
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
02How it works
From .ies to lux in three moves.
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 uploads and no server-side render. An account gates the tool; what you draw never leaves the tab.
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 uploads and no tracking cookies. Your project stays browser state, not a server
record; page views are counted anonymously.
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.
v0.9.0 is tagged and in use. Geometry is here: 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.
v0.9.0
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.
v0.5.1
Added
Self-hosted, cookieless site analytics (Umami) on the landing page and in the tool. The Content-Security-Policy in deploy/Caddyfile was opened for that origin, and the copy that promised "no analytics" now says what actually happens.
Three lux isolines instead of one, each with its own enable checkbox and level, drawn in colour and dash so they can be told apart. Projects saved with the single isoline keep their level, enabled, in the first slot.
A maintenance factor (MF), modelled on the way DIALux does it. The fixed method is one factor for the room, set by slider, by preset or by typing it; the detailed method multiplies the four CIE 97 factors (LLMF × LSF × LMF × RSMF) entered as percentages. The factor is applied per luminaire, so any fixture can carry its own override from the inspector and inherit the room value otherwise. Results become maintained illuminance — heatmap, metrics, isoline and target compliance — rather than as-new, and the metrics panel shows the maintained average beside the as-new figure. New projects start at 0.80; projects saved before this keep 1.00, so their numbers do not move.
A lux isoline on the plan and the 3D work plane. Pick a level — 100, 200, 300, 500 or any value — and the layout draws the contour where the work plane crosses it, labelled in place. It follows the heatmap component selector, so it traces total, direct or reflected light, and changing the level never triggers a recalculation. On the demo room the 200 lx line runs just inside the walls, with 741 lx at the centre and 148 lx in the corners.
Grid placement is an explicit action now, not a live mode. Pick the luminaire you want to repeat — or leave nothing selected to use the active profile — set columns and rows, and press Apply. The block is written into the project at cell centres in one step. The selected luminaire becomes the block, so one light plus 3 × 2 leaves six in the grid rather than one plus six, and every other luminaire stays where it is. Freehand remains the default, and older projects still load as Freehand with no isoline.
Fixed
The selected luminaire's name is a crisp DOM badge pinned to the fixture instead of a canvas-textured sprite. The sprite was sized in metres, so on a phone its 22px label collapsed to a couple of pixels and read as an unreadable black bar over the heatmap; long names also clipped at the texture edge. The badge keeps a constant screen size, truncates with an ellipsis and sits above the fixture rather than on the work plane.
Changed
The IES library is one list instead of two tabs. Your own files and every supplier catalogue sit together, filtered by brand (All, Mine, then one chip per brand), with search across all of them.
Catalogues are data: a brand is a name, an attribution and a set of fixture families (src/lib/catalogue/brands.ts). OrbitX is the first entry; adding another supplier is a new registry entry, not a code change.
Changed
The IES library is preview and file management only. It no longer sets the default profile or assigns one to a luminaire; choosing a profile happens in the Luminaires panel, where the Add picker and the inspector already live.
Changed
Sign-in throttling is far more forgiving: 20 attempts per 15 minutes per identity (was 5) before a 2-minute pause, and the message now says how long to wait. Both values are tunable with LUXLAB_MAX_LOGIN_ATTEMPTS and LUXLAB_LOCKOUT_MINUTES without a code change.
Added
The tool opens on a project list: naming, room size, luminaire count and last edit, with New project and Load demo. Nothing is created or opened on your behalf any more; deleting the last project returns to the list.
New projects ask for their dimensions: room width, depth and height plus the work plane height, validated against the ceiling, instead of always starting at 6 × 4 × 3 m.
Changed
The projects dialog's New project button opens the same dimensions dialog.
Added
Adding a luminaire opens a picker instead of silently reusing the last active profile. It lists both the profiles already in the library and the 97-profile OrbitX catalogue, searchable by name, family, SKU or file; picking a catalogue entry imports it once, exactly as the IES library does. Type A/B catalogue entries are listed but disabled, and the active profile is preselected.
Fixed
The landing page advertised v0.2.0 in its version chip, roadmap line, CTA and footer while v0.5.0 was deployed. It is now stamped from package.json at deploy time, and npm run check:versions (wired into npm run check and the release preflight) fails when the README, DEPLOY or landing page disagree with package.json.
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.
