How would you go in doing a terrain quad tree based LOD ? Something ROAM, or this : https://www.gamasutra.com/view/feature/131841/continuous_lod_terrain_meshing_.php?page=2. First, what would be an ECS friendly or cache-friendly way to structure a quadtree? Or even a good way to make the tree without reference types ? Also, how would you deal with all the "horizontal dependencies" in the tree (dependent activation of vertices) ? I know the question is a little big vague, I just don't know where to start.