1. Choose the outside diameter
A 21×21 circle occupies a 21-block-wide square. Odd diameters have one center block; even diameters are centered between the middle four blocks. Decide the footprint before placing your first anchor.
2. Mark the center and four anchors
From the center, mark the north, south, east and west extremes of the circle. These anchors establish the outside boundary and make symmetry much easier to maintain.
3. Build with row segments
Do not count individual pixels from an image. Treat every row as one or more horizontal runs. For example, a row might contain two blocks on the left, a gap, and two blocks on the right. VoxelCurve shows the exact columns and center-relative offsets.
4. Check symmetry as you go
Every left-side run should have a corresponding right-side run. The same is true for top and bottom halves. If a row looks wrong, fix it immediately instead of carrying the offset into later rows.
5. Scale the method for large circles
For a 31×31 or larger circle, keep the center marked and use exact segment positions rather than repeatedly recounting from the boundary. This reduces cumulative errors on long walls and arena foundations.
Example sizes
11×11
A compact size for wells, towers and decorative builds.
Open blueprint →21×21
A useful medium footprint for rooms, tower bases and observatories.
Open blueprint →31×31
A large circle where guided rows save significant counting time.
Open blueprint →