Create a single Voxel of Terrain in Roblox

roblox-create-voxel-of-terrain.lua

 local Terrain = game:GetService("Workspace").Terrain
 
-- The resolution required for Terrain system.
local terrainResolution = 4

-- The smallest possible voxel size.
local region = Region3.new(Vector3.new(0,0,0), Vector3.new(4,4,4))

-- The material as a 1x1x1 3d-grid. What material should go in the voxel?
local material = {
    {
        {Enum.Material.Water}
    }
}
  
-- The occupancy values of the voxel grid. How full should each voxel be?
local occupancy = {
    {
        {1}
    }

}

Terrain:WriteVoxels(region, terrainResolution, material, occupancy)