Stairset: Twelve stairs, a square rail and a low sun
A stair set built from its numbers, framed where a filmer would crouch and lit for long shadows.
The finished twelve: 3 m wide, 2.16 m high, a square rail down the middle and the sun 13° above the horizon. Rendered in Stairset and downloaded as the free A5 PNG.
Skateboarders name a stair set by its count: the Hollywood 16, El Toro's 20, the Lyon 25. Nobody names a corridor after its length. I noticed that I look at stairs differently: where most people see a way up, I see a set to skate. These pieces share that appreciation for a good stair set. If you don't skate, you will most likely not see the point, and that is fine; it is a side effect, not the aim.
Stairset builds a stair from a handful of numbers and renders it. Below is how the twelve above came out of the app's defaults in five moves, and why each one mattered. Open this exact stair set and follow along.
How this one got made
Twelve steps, three metres wide
The app opens on a garden stair: eight steps, one metre wide, grey on grey, with a round rail on the right. Before anything else, open Colours, choose Earth Tone Serenity from Quick palette and click the dark green swatch for BG, the cream for Stairs and the red for Rail. Then, under Steps, set Width m to 3.00 and Step count to 12. Riser m and Tread m stay at 0.18 and 0.28.
The count is the one number that changes what the set is. A four is a warm-up, a twelve is a session, a twenty is a career.
The same stair at 4, 12 and 20 steps, shown at one scale so the heights compare: 0.72 m, 2.16 m and 3.60 m. Each frame is the app's preview at the default camera, zoomed out to 0.75 so the twenty fits.
A run-up at the top, a roll-away at the bottom
Open Extensions and set Top m to 4.00 and Bottom m to 3.00. The architect calls these flat ends the arrival and the approach. Everyone else calls them the run-up and the roll-away. Coming down the set, the run-up is where the speed comes from and the roll-away is where the landing goes, so a set with neither is a set nobody rides.
Rail follows bottom and Rail follows top are ticked from the start, so the rail carries on over both platforms.
The twelve side on, drawn from the app's own geometry for these settings. Read it right to left: 4 m of run-up, the drop of 2.16 m, 3 m of roll-away, with the rail 0.90 m above the treads the whole way.
Down to where the filmer crouches
With 7 m of platform added, the default camera frames a small ramp in the middle of a large dark field. Open Camera and set Azimuth° to −75, Elevation° to 8, Zoom to 3.6 and Pan ◀▶ to −0.04. That puts the lens near the foot of the set, looking up it, close enough that the steps fill the frame.
The preview is a render of the export itself, at screen size. I gave up drag-to-rotate for sliders to get that: the in-browser 3D viewer the app used to have never matched the file it exported, in light or in framing.
Same stair, two cameras. Left, the default (Azimuth −45°, Elevation 30°, Zoom 1): the platforms swallow the set. Right, Azimuth −75°, Elevation 8°, Zoom 3.6: the twelve becomes the subject.
A square rail down the middle
Open Handrail. Enable handrail is already on. Set Placement to Middle, so the rail splits the set in two, and try each Type.
Round, Square and Curb from the same camera. Round and Square differ only in how the light falls along the bar; Curb swaps the bar for a solid ledge that runs down the slope.
At this distance Round and Square are close to identical, so the choice is taste. This one uses Square. Curb is a different object altogether, a ledge rather than a rail.
A low sun for long shadows
Last, open Lighting. Cast shadows is on from the start. Move Sun elevation° from 53 down to 13 and Sun azimuth° round to −120, so the light comes in low from the front left.
Two things change at once. The risers, which face the low sun, go light, and the treads go darker. And the rail's shadow leaves the rail: it falls well to the right of it and breaks over every step nose.
Sun 53° against sun 13°, same stair and camera. Look at the right half of the steps: the low sun throws the rail's shadow across it, and the lit faces swap from treads to risers.
The shadows are worked out from the geometry before the render. I dropped the renderer's own shadow maps after trying them twice, because they lost the shadow of a 5 cm rail.
From screen to object
Open the Downloads at the bottom of the page and tick the terms once. OBJ is the stair as a mesh. I added it so a final render can move to Blender, rather than the app growing its own lighting rig. PNG, under Print render, is the picture at the top of this post: A5 at 300 dpi, with a small signature in the corner.
What a visitor gets for this twelve: the mesh, the A5 render, and a print order folded away underneath.
Order a print of this creation prints the same render on fine art paper or canvas. The sizes stop at A2, because above that one render needs about 4.8 GB of memory on the server that draws it.
Other controls, one line each
+ Add landing splits the flight into runs with a flat landing between them: two runs make a double set, and the app allows up to four.
Post density and Snap posts to step decide how many posts hold the rail and whether they stand on the tread centres.
Rail diameter cm sets the thickness of the bar and posts (Round and Square only).
Roll° and Pan ▼▲ tilt the horizon and slide the frame up or down.
Shadow darkness sets how deep the cast shadows are.
Orientation, under Viewer, turns the preview and every download to Portrait.
↺ Reset to defaults at the bottom of the controls goes back to the garden stair.
Your turn
Open this exact twelve and change one thing. Make it a twenty, or swap the rail for a Curb, and watch how much of the frame the set takes.
If you build a set you like, send me what you made. I'll ask before showing it anywhere.