A sphere is a stack of layers
Each height intersects the sphere at a different radius. Middle layers are widest, while the top and bottom contract toward a cap.
Hollow and filled output
Filled output includes every voxel whose center is inside the radius. Hollow output keeps the outer shell and removes voxels farther inside than the selected thickness.
Dome extraction
A dome uses the upper half of the same deterministic sphere calculation, rebased so its widest layer becomes the build floor.