resource

Prefab

Prefab = GetEntity(authoring.Prefab,TransformUsageFlags.Dynamic)

PrefabReference

运行时加载 Prefab

var prefabEntity = new EntityPrefabReference(authoring.Prefab);

• EntityPrefabReference : 在 entity 上添加 Prefab 弱引用

• RequestEntityPrefabLoaded : 请求 Prefab 加载

• PrefabLoadResult : 判断 Prefab 加载完成并实例化

Reference

用 Reference 引用序列化好的, 但是未被加载进内存的 Unity 资产

[Serializable]  
public struct References : IComponentData  
{  
public EntitySceneReference EntitySceneReference;  
public EntityPrefabReference EntityPrefabReference;  
public WeakObjectSceneReference GameObjectSceneReference;  
public WeakObjectReference<GameObject> GameObjectPrefabReference;
}

加载

判断引用合法

refs.EntitySceneReference.IsReferenceValid

EntityReference

资产加载后自动转化为 Entity, 仅支持 Scene 和 Prefab

场景

SceneSystem.LoadSceneAsync(state.WorldUnmanaged, refs.EntitySceneReference)

Prefab

SceneSystem.LoadPrefabAsync(state.WorldUnmanaged, refs.EntityPrefabReference)

判断加载成功

SceneSystem.GetSceneStreamingState(state.WorldUnmanaged, loading.EntityPrefab) ==  
SceneSystem.SceneStreamingState.LoadedSuccessfully)

WeakObjectReference

全生命周期控制任意 Unity Object 生命周期

Scene

// Load GameObject Scene  
if (!loading.GameObjectScene.IsValid() && refs.GameObjectSceneReference.IsReferenceValid)  
{  
    loading.GameObjectScene = refs.GameObjectSceneReference.LoadAsync(new ContentSceneParameters  
    {  
        autoIntegrate = true, loadSceneMode = LoadSceneMode.Additive,  
        localPhysicsMode = LocalPhysicsMode.None  
    });  
}

Prefab

// Load GameObject Prefab  
if (loading.GameObjectPrefabInstance == null &&  
    refs.GameObjectPrefabReference.IsReferenceValid)  
{  
    if (refs.GameObjectPrefabReference.LoadingStatus == ObjectLoadingStatus.None)  
    {        refs.GameObjectPrefabReference.LoadAsync();  
    }  
    if (refs.GameObjectPrefabReference.LoadingStatus == ObjectLoadingStatus.Completed)  
    {        loading.GameObjectPrefabInstance =  
            Object.Instantiate(refs.GameObjectPrefabReference.Result);  
    }}

Scene Load

Scene Loading

使用 LoadSceneAsync 加载 EntitySceneReference

SceneSystem.LoadSceneAsync(state.WorldUnmanaged, requests[i].Value);

使用 SceneSystem.SceneStreamingState 监控加载状况

SceneSystem.GetSceneStreamingState(state.WorldUnmanaged, scene.EntityScene);

分段加载 SubScene 中的 Section

state.RequireForUpdate<SceneReference>(); : 在有 SceneReference 时才执行
ResolvedSectionEntity : 所有 Section
RequestSceneLoaded : 加载 Section
DisableSceneResolveAndLoad : 禁止自动加载 Section

基于 Volume 的 Section 流式加载

6. StreamingVolume

SubScene 流式加载

7. SubsceneInstancing

使用 POstLoadCommandBuffer, 在 SubScene 加载完执行 Cmb

// A PostLoadCommandBuffer wraps an EntityCommandBuffer that will execute commands  
// after the subscene instance is loaded.  
var buf = new PostLoadCommandBuffer();  
buf.CommandBuffer = new EntityCommandBuffer(Allocator.Persistent, PlaybackPolicy.MultiPlayback);

state.EntityManager.AddComponentData(sceneEntity, buf);

包括 LOD

8. Complete