GetSkinnedEntityAuthoring.cs

using Unity.Burst;
using Unity.Collections;
using Unity.Entities;
using Unity.Rendering;
using UnityEngine;

namespace Junk.Rendering.Hybrid
{
    //Short notes: requires internal access asmref trick
    public class GetSkinnedEntityAuthoring : MonoBehaviour
    {
        public SkinnedMeshRenderer skinnedMeshRenderer;
        public class GetSkinnedEntityAuthoringBaker : Baker<GetSkinnedEntityAuthoring>
        {
            public override void Bake(GetSkinnedEntityAuthoring authoring)
            {
                var entity = GetEntity(TransformUsageFlags.Dynamic);
                
                var smrEntity = GetEntity(authoring.skinnedMeshRenderer, TransformUsageFlags.Dynamic);
                AddComponent(entity, new FindSkinnedEntityData
                {
                    SkinnedEntity = smrEntity
                });
            }
        }
    }

    [TemporaryBakingType]
    public struct FindSkinnedEntityData : IComponentData
    {
        public Entity SkinnedEntity;
    }

    [WorldSystemFilter(WorldSystemFilterFlags.BakingSystem)]
    public partial struct GetSkinnedEntitySystem : ISystem
    {
        [BurstCompile]
        public void OnUpdate(ref SystemState state)
        {
            var ecb = new EntityCommandBuffer(Allocator.Temp);
            
            foreach (var (findSkinnedEntityData, entity) in SystemAPI.Query<RefRO<FindSkinnedEntityData>>().WithEntityAccess())
            {
                var smrEntity  = findSkinnedEntityData.ValueRO.SkinnedEntity;
                var skinnedEntityList = new NativeList<Entity>(Allocator.Temp);
                
                foreach (var (deformedEntity, skinnedEntity) in SystemAPI.Query<RefRO<DeformedEntity>>().WithEntityAccess())
                {
                    if (deformedEntity.ValueRO.Value.Equals(smrEntity))
                    {
                        skinnedEntityList.Add(skinnedEntity);
                    }
                }

                Debug.Log($"Found {skinnedEntityList.Length} skinned entities");
                if (skinnedEntityList.Length > 0)
                {
                    var skinnedEntityBuffer = ecb.AddBuffer<SkinnedEntityData>(entity);
                    foreach (var skinnedEntity in skinnedEntityList)
                    {
                        skinnedEntityBuffer.Add(new SkinnedEntityData { Value = skinnedEntity });
                    }
                }
            }
            
            ecb.Playback(state.EntityManager);
        }
    }
    
    public struct SkinnedEntityData : IBufferElementData
    {
        public Entity Value;
    }
}