Rayon: the AI that hands back geometry, not pictures

Every AI tool most architects have met returns an image. You look at it, you judge it, and if it travels anywhere it travels into a presentation, where nobody mistakes a JPEG for the drawing. Rayon's AI returns polylines and CAD blocks, placed in the same file you will later export as DWG and issue. A traced line carries no extension announcing where it came from.

What it is and who makes it

Rayon is a browser-based 2D CAD platform, founded in 2021 by Bastien Dolla and Stanislas Chaillou and run from Paris. Chaillou is the half of that pair worth knowing about: an architect and former Autodesk employee whose graduate research at Harvard was on generative floor-plan layout, years before anyone was selling it. The founders describe the product as light-BIM — CAD drawing commands carrying some of the structured data a BIM tool would hold, and none of the modelling.

It runs entirely in a tab. Multiplayer editing, version history, DWG, DXF, PDF and image import and export, a block library Rayon puts at over 4,000 items, more than a hundred templates, schedules, and markup directly on the canvas. Reported seed funding is €4 million co-led by Northzone and Foundamental, with Norman Foster among the angel investors; that figure comes from trade coverage rather than Rayon's own site. The published customer list leans hard toward flexible-workspace and hospitality operators — Wojo, Numa, Edgar Suites, Goldbeck — which tells you a good deal about the work the tool was shaped by.

AI arrived on top of all of this, and Rayon's own documentation still labels the entire feature set Beta. It lives in two places: a chat panel, and an AI section of the toolbar. Nowhere on the pricing page or in the AI documentation does Rayon say which models run any of it.

Where it sits in your week

Monday, a landlord sends a PDF of an existing floor plan — scanned, north point at an angle, dimensions half legible. AI tracing converts it into a vectorized wireframe you can snap to. This is the command that gets Rayon into offices. The rest follows it in.

Wednesday, a client asks on a call what the reception reads like in three dimensions. Generate axonometry takes a screenshot of the plan and returns an axonometric view before the call ends. It is an image of an axonometric, not an axonometric. Useful anyway, at that moment.

Friday, the FF&E schedule. A client has sent a photograph of a chair with no manufacturer DWG behind it. AI product generation produces the three views of a CAD block from that photograph, and the chair gets a plan symbol and a row in the schedule without a week of waiting.

What it is genuinely good at

Redrawing what already exists. Fit-out and refurbishment practices spend real fee converting somebody else's PDF into something editable, and that is exactly the job the tracing was built for. Independent reviewers and Rayon's own published testimonials agree on the direction, if not on a number — treat the hours-saved claims as claims, since every one of them is customer-reported through the vendor.

The second thing it does well is get non-architects onto the drawing. A landlord's agent, a client, an operator's facilities lead: a link, a browser, comments on the canvas. No licence, no viewer, no PDF round trip. For a small practice that removes an entire category of Tuesday.

Where it breaks

Once traced geometry is in the model, nothing in the file says it was traced. No AI layer, no tag, no property. The Jobs tab in the AI panel keeps a list of AI runs, which is the closest thing to a record — and it sits beside the model rather than in it, and jobs can be deleted from there. Export the drawing and even that thin trace is gone. Your issue sheet records who drew the sheet. It cannot record which lines were drawn.

That matters more here than in a renderer, because tracing is lossy on purpose. Rayon's documentation says the command will simplify the scene before vectorizing it. A simplified survey is a survey you have not checked, and it now looks precisely like one you have.

The remaining limits are ordinary and easy to plan around. It is 2D. Generation credits reset weekly — two a week on Free, 100 on Pro, 200 on Team — so it will not carry a heavy tracing push in the last week of a bid. And the AI is in Beta, by Rayon's own label, which is the right thing for them to say and the right thing for you to plan around.

What it costs, what it asks

From Rayon's pricing page in September 2026, in euros, with no tax basis stated: Free at zero, Pro at €19 per month billed yearly or €21 monthly, Team at €35 per editor per month billed yearly or €38 monthly. Chat credits are unlimited on both paid tiers; the weekly generation credits are the real meter. At Pro this sits below the threshold at which most practices hold a meeting about software, which is the point.

The free tier is where a practice gets caught, and Rayon states the mechanism plainly in its own documentation: on the Free plan, all models are Public by default. Public means visible to everyone in the Rayon community, where anyone can view them, duplicate them, and use them as templates. Private models require Pro or Team. Downgrade later and your private models stay private but drop to read-only. Separately, free accounts are asked to sign in at least once every three months to keep their models in the account.

Read that back with a client's name in the title block. The three-month rule is housekeeping. The public default is a confidentiality decision your appointment did not make.

Who should bother

The principal: Watch rather than buy — unless the office does fit-out or refurbishment work, where the tracing alone justifies a few Pro seats within a month. The condition attached is one line in the office manual: no client model on the free tier, ever.

The project architect: Worth an evening if you redraw landlord PDFs. It is not a Revit replacement, and Rayon does not claim it is.

The graduate: Free for students and faculty, so the cost of finding out is an hour. Learn what the tracing gets wrong before you learn what it gets right.

The profession has spent two years arguing about whether an AI image can be trusted in a planning pack. Rayon moves that argument one file type to the left, into the drawing itself, where the answer matters more and the evidence is thinner. If your office adopts it, the useful response is not a policy on AI. It is a layer.