Greedy meshing blocks in a voxel game doesn’t have to be hard. Here’s a simple explanation for people who prefer seeing how the algorithm progresses.

This post is the newer version of my popular tutorial from the Roblox DevForum: Consume everything - how greedy meshing works

The algorithm

• Find a starting point, that isn’t empty, and hasn’t already been merged.
• For each axis, one at a time (X, Y, Z)
  • Look one coordinate ahead. Is there a block?
  • If so, merge it with the previous block and step forward.
  • If not, then move on to the next axis.
• Repeat the above steps until you have merged every block.

By the way, finding a starting point isn’t too hard. It’s pretty sufficient to just loop over them in the normal way - you’ll always have merged every block by the end, and it’s relatively efficient at merging things into large groups.

for x = 1, size.x do
    for y = 1, size.y do
        for z = 1, size.z do
			-- if this is a starting point, start merging stuff...
		end
	end
end

A simple visual example along one axis

The same example, with two axes (2D)

A more complex demonstration