ECS LOD test

LODTest.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

using Unity.Entities;
using Unity.Mathematics;
using Unity.Collections;
using Unity.Transforms;
using Unity.Rendering;

public class LODTest : MonoBehaviour
{
    public Mesh mesh;
    public Mesh meshLod0;
    public Material material;

    NativeArray<Entity> entities;

    public float separation = 1;

    EntityManager manager;

    private void Start()
    {
        manager = World.Active.GetOrCreateManager<EntityManager>();

        int size = 100;
        entities = new NativeArray<Entity>(size * size, Allocator.Persistent);
        
        for (int y = 0; y < size; y++)
        {
            for (int x = 0; x < size; x++)
            {
                var position = new float3(
                    x * separation, 0,
                    y * separation);

                SpawnWithLOD(position);
            }
        }
    }

    void SpawnWithLOD(float3 position)
    {
        // LOD GROUP
        Entity lodGroup = manager.CreateEntity(
            typeof(MeshLODGroupComponent),
            typeof(ActiveLODGroupMask),
            typeof(Position),
            typeof(RenderMesh),
            typeof(MeshLODComponent));

        var mlogc = new MeshLODGroupComponent()
        {
            LODDistances0 = new float4(50, 100, 200, 400),
            WorldReferencePoint = position
        };

        var pos = new Position() { Value = position };

        var rm = new RenderMesh()
        {
            material = material,
            mesh = mesh,
        };

        var mloc = new MeshLODComponent()
        {
            Group = lodGroup,
            LODMask = 1
        };

        manager.SetComponentData(lodGroup, mlogc);
        manager.SetComponentData(lodGroup, pos);
        manager.SetSharedComponentData(lodGroup, rm);
        manager.SetComponentData(lodGroup, mloc);


        // LOD 1
        Entity lod2Entity = manager.CreateEntity(
            typeof(Position),
            typeof(RenderMesh),
            typeof(MeshLODComponent));

        var rm2 = new RenderMesh()
        {
            material = material,
            mesh = meshLod0,
        };

        var mloc2 = new MeshLODComponent()
        {
            Group = lodGroup,
            LODMask = 2
        };

        manager.SetComponentData(lod2Entity, pos);
        manager.SetSharedComponentData(lod2Entity, rm2);
        manager.SetComponentData(lod2Entity, mloc2);
    }

    private void OnDestroy()
    {
        entities.Dispose();
    }
}