okay as for my MC clone:
how i achieve kilometers of render distance: you know the chunks are stored in a hashmap for the chunks with their chunk coords etc... so think of that but instead we get 5 of them.
basically the LODs are just separate grids of chunks, and chunks also know what LOD level they are so when rendered their LOD is also taken into account, so LOD0 chunks are rendered in LOD0 chunk coords, while LOD1 chunks are rendered in LOD1 chunk coords, and so on until LOD4.
and each LOD is 2x2 its previous level, so LOD1 is 2x2 LOD0 space, LOD2 is 2x2 LOD1 space, and so on, until LOD4 where it takes the 16x16 LOD0 space.
also each LOD level has the same 16x128x16 (to be faithful to Alpha) voxel data, and they are all meshed the same, the only difference is when generating LOD chunks the terrain generator itself skips the worldX and worldY and worldZ by the LOD factor.
and so basically instead of just one grid of chunks, i have 5 grids of chunks all stacked on top of each other and each using the chunk coords for their own LOD level..
and if you wanna calculate the render distance, basically take the length of LOD4 chunk and multiply it by the render distance, so LOD4 chunks have the length and width of 256 blocks, and on 16 chunks render distance radius, it ends up as 16x256 = 4096 blocks of render distance