Generate spheres, domes and circles layer by layer to build round shapes
Building a sphere or dome in voxel games like Hytale and Minecraft is hard because everything is made of square blocks. This tool solves that by slicing the shape into horizontal layers: for each height level, it computes exactly which blocks form that ring or disk. You choose between a sphere (full), a dome (half sphere with a flat base) or a circle (a single layer), set the diameter and decide between a hollow version, just the shell, ideal for domes and empty balls, or solid. A slider walks through the layers from bottom to top, showing the block count of each level, so you can reproduce the shape block by block in-game. It is pure geometry, with no dependency on any specific game's data.
In a block game, a sphere is always an approximation: each block occupies a cell of a 3D grid, and the tool decides whether each cell is inside or outside the sphere by testing the distance from the block's center to the center of the shape. If that distance is less than or equal to the radius, the block is in; otherwise it is out. The radius is half of the diameter you set, and the result is sliced into horizontal layers, from bottom to top, with the block count of each level.
You choose between three shapes and two fills. A sphere is the full ball; a dome is just the top half, with a flat base on the ground; a circle is a single disk (one layer). In solid mode the whole volume is filled; in hollow mode the tool keeps only the shell, every block that borders empty space, leaving the interior open and saving a lot of blocks.
Example 1, a dome of diameter 16, hollow: perfect for a vaulted ceiling or an observatory. The base is the widest ring, almost 16 blocks across, and each layer above closes in a little until it becomes a small cap at the top. By building from bottom to top and following the block count of each layer, you don't have to guess the curve.
Example 2, a sphere of diameter 10, hollow versus solid: the solid version fills all 10 layers completely and uses far more blocks; the hollow one keeps only the outer shell, leaving the core empty. For a decorative planet or a giant ball, the hollow version drastically cuts the number of blocks and the build time while keeping the same round outline on the outside.
The tool works for any round build in voxel games: domes, cylindrical towers (stacking circles), planets, arenas, fountains, tanks and rounded details. Because it is just geometry, it works the same in Hytale, Minecraft, Vintage Story and any block-based game, all that changes is how you place the blocks in the world.
There are practical limits. Spheres and domes go up to 64 blocks in diameter and circles up to 128; for giant structures, generate in parts and combine the layers. Very small diameters (2 or 3 blocks) look more square, because there are few blocks to draw the curve, and even and odd diameters produce slightly different symmetries. Everything is computed in the browser, without depending on any specific game's data.
Paste the code into your HTML and the tool shows up on your page, without J-Kit's navigation and ads. It still runs in the browser of whoever visits your site.
<iframe
src="https://jkit.tools/embed/en-US/voxel-sphere-generator"
width="100%"
height="600"
style="border:0"
loading="lazy"
title="Voxel Sphere Generator"
></iframe>These references help contextualize formulas, standards, APIs and limitations used on this page. They do not replace professional validation when a result has legal, financial, medical or operational impact.
Generate the sphere at the diameter you want and build level by level, bottom to top, following the layer shown for each height. Start from the middle layer (the widest) to orient yourself and close in toward the top and bottom. The hollow version saves many blocks.
The shape is computed locally in the browser; nothing is sent to servers.