A dome built from rhombic panels instead of triangles. Geometrically it is a polar zonohedron: take a number of struts of equal length, tilt each one the same angle from vertical and spread them evenly around an axis. Every pair of them spans a rhombus, and every edge of every rhombus is one strut long.

That is the whole appeal for the builder: every strut is the same length. What changes from row to row is only the angles.

Fold is the number of panels in each ring around the axis — a 10-fold zome has ten panels per row. Strut tilt is the angle of the struts from vertical: steeper makes the zome taller and narrower.

Rows are counted from the apex: z1 is the ring of panels around the top, z2 the next ring down, and so on. A full zonohedron closes at z(fold − 1). Start below z1 for an opening at the top; stop early for an open base you can stand in.

Every panel has a coordinate row,panel. The row is the same number the specs table uses, so 1,1 is the first panel of row z1 and 3,7 the seventh panel of row z3. Within a row the count runs from 1 up to the fold, the same way round the axis every time.

Tick Panel coordinates in the View section to write them on the model — useful for labelling the frames as you build, since panels in a row are identical but their neighbours are not. Rows stagger by half a panel going down, so 2,1 sits between 1,1 and 1,2 rather than straight below.

Every panel is one of three things, and clicking it in the view walks it round them:

1. Solid — the panel as built.
2. Glazed — the same rhombus in clear plastic. A window.
3. Open — nothing there at all. A doorway, or a vent.

One more click brings it back to solid. Both lists appear under Panels beside the view, and a coordinate there puts its panel straight back to solid. They travel in the share link with everything else.

Struts along the edge of an opening have nothing to meet, so they are cut square there rather than beveled; the rest of the row still gets the angle listed in the specs table. A glazed panel is not an opening — it keeps its neighbours, so its struts keep their bevels.

Clear plastic sheet — acrylic (PMMA, "plexiglass") or polycarbonate — cut to the same rhombus as the panel it replaces. Set the thickness under Glazing thickness in the Construction section: 4–6 mm is the usual single sheet, and twin-wall polycarbonate runs thicker.

Plastic is the normal choice over real glass here. Panels are rhombi rather than rectangles, every row is a different size, and the sheet has to be cut to an angle no glazier stocks — plastic you can cut yourself with a fine-toothed blade, and it weighs a fraction of glass, which matters on a shell held up by 45 mm struts.

Glazing sits in the frame exactly where the panel would, so the struts, bevels and angles are unchanged — a glazed panel is a material choice, not a structural one. The specs table counts the glazed panels in each row and totals the sheet area, so you know what to order. Glazing shows in the view whatever Style is set to, and exports as its own group per row, ready to be given a glass material in SketchUp.

Use Explode struts in the View section to pull the four apart and look at the cuts.

Switch to the Cut guide page. It takes one strut at a time and shows what it costs to make: the blank it starts as — the shortest square-ended length of your lumber the piece fits inside — the cuts that take it from there, and the offcuts each one drops. Every sawn face is coloured by the cut that made it, and the same colours run through the flat plan and section beside the view, so a red face on the piece is the red wedge in the drawing.

A strut is named by where it sits in its panel, seen from outside: 3,1 top-left is the upper-left edge of the first panel of z3. Pick one with the diamond in the side panel, or click any strut in the view — including one in a neighbouring panel, which walks you round the shell piece by piece. From the design page, shift-click a panel, or follow the cuts → link on its row in the specs table.

Three cuts, in the order you would make them:

1. The rip down the outer edge, at half the angle to the panel across that edge. Only when Bevel struts is on; square struts skip it.
2. End A, which lands on a rhombus edge shared with another panel — so it is mitred and tilted, a compound cut.
3. End B, mitred at the same table angle with the blade square, because only the next strut round the panel touches it.

Both ends take one table setting and the board is not flipped between them: every strut is a parallelogram. Under the guide, every piece this shell needs lists the distinct jobs with how many of each — normally four per row, since the upper and lower edges carry different bevels, plus extras wherever an opening has taken a bevel away.

Neighbouring panels meet at an angle. Here is a cross-section through one seam, looking along the shared edge:

Tick Bevel struts in the Construction section to switch between the two.

The rhombi — and therefore strut length, widths, heights and diameters — describe the outer surface of the frames. The struts hang inside that surface by Lumber depth, so the room inside is smaller than the numbers by that much, and a cover skin goes on the outside exactly at the drawn size.

Height is measured from the ground to the apex. The lowest built row stands on the ground.

Everything you set lives in the address bar. Press Copy link and paste it anywhere — whoever opens it sees your exact design. Your last settings are also remembered in this browser.

The geometry is exact, but this is a design tool, not engineering advice.