Converting a model to an entity in runtime

Unity Engine
, , ,
1

Hello! I have a RTS game project. The task is to create an entity in runtime from a prefab, which is defined in the SO. There is a house model with separate meshes for doors. There is a code that displays one material out of 10 in the scene and one sub mesh, how to display all the materials and sub meshes? Should I create an entity for each sub mesh? How to display additional door meshes with the correct local position? Unity 6000.043, Entities 1.3.10. (Update: I edited code a little).

private Entity ConvertGameObjectToEntityPrefab(GameObject prefab)
        {
            MeshFilter meshFilter = prefab.GetComponent<MeshFilter>();
            MeshRenderer meshRenderer = prefab.GetComponent<MeshRenderer>();

            Entity entityPrefab = EntityManager.CreateEntity(
                ComponentType.ReadWrite<BuildingComponent>(),
                ComponentType.ReadWrite<Prefab>(),
                ComponentType.ReadWrite<LocalTransform>()
            );

            Material[] materials = meshRenderer.sharedMaterials;
            Mesh mesh = meshFilter.sharedMesh;
            int subMeshCount = mesh.subMeshCount;

            var renderMeshArray = new RenderMeshArray(
                materials,
                new[] { mesh }  // Still one mesh, but with multiple submeshes
            );

            var renderMeshDescription = new RenderMeshDescription(
                shadowCastingMode: ShadowCastingMode.On,
                receiveShadows: true
            );

            RenderMeshUtility.AddComponents(
                entityPrefab,
                EntityManager,
                renderMeshDescription,
                renderMeshArray,
                MaterialMeshInfo.FromRenderMeshArrayIndices(0, 0)
            );

            EntityManager.SetComponentData(entityPrefab, LocalTransform.FromPositionRotationScale(
                float3.zero,
                quaternion.identity,
                1f
            ));


            return entityPrefab;
        }
2

Tried to create entity for each material, no errors and no entities in scene.


for (int i = 0; i < submeshCount; i++)
            {
                Entity childEntity = EntityManager.CreateEntity(
                    ComponentType.ReadWrite<Prefab>(),
                    ComponentType.ReadWrite<LocalTransform>(),
                    ComponentType.ReadWrite<Parent>()
                );
                
                EntityManager.SetComponentData(childEntity, new Parent { Value = parentEntity });
                
                EntityManager.SetComponentData(childEntity, LocalTransform.FromPositionRotationScale(
                    float3.zero,
                    quaternion.identity,
                    1f
                ));
                
                var renderMeshArray = new RenderMeshArray(
                    new[] { materials[i] },
                    new[] { mesh }
                );
                
                RenderMeshUtility.AddComponents(
                    childEntity,
                    EntityManager,
                    renderMeshDescription,
                    renderMeshArray,
                    MaterialMeshInfo.FromRenderMeshArrayIndices(0, 0, (ushort)i)
                );
            }