Set the width of the base and how many layers tall the dome is. Each layer is shown on its own with its block count, from the base up to the top.
| Row (z) | Blocks | Runs |
|---|
Runs read left to right, alternating blocks and gaps: 2-6-2 = 2 blocks, 6 empty, 2 blocks.
| Layer | Blocks | Running total |
|---|
A dome here is the top half of a rounded shape whose widest point is its base. Make the height half the width for a true hemisphere (a 24-wide dome that is 12 layers tall is exactly the top half of a 24-block sphere). Make it taller for a pointed, onion-style dome or lower for a flat, shallow one. The hollow dome is open at the bottom, so it sits on your walls.
Build layer 1 on top of your walls, then step up through the layers. The base layer of a hemisphere covers exactly the same footprint as a circle of the same width, so its outside edge lines up with a round wall made with the circle generator. In a hollow dome the base ring can be a block thicker in places, where the layer above steps inwards. The layer table gives the blocks per layer and a running total.
A block is placed when the centre of that block lies inside the circle (or oval, sphere or dome) that exactly fits the width and height you chose. Outlines keep every block of the filled shape that is within your thickness of the outside: Sealed counts corner neighbours too, so the inside never touches the outside even diagonally and the wall has no diagonal gaps; Thin counts only side neighbours, which uses fewer blocks but lets wall blocks meet at a corner.