ECS for HexSphereSubdivision

Hello,

Im currently porting my game to ECS since I hit a performance limit that ESC can solve.
In my old system this was a simply two struct arrays (HexTri[] , HexTri[] ).

Code (csharp):

1.  
2.     /// <summary>
3.     /// HexTri - A Hextri is an element of the dual of the (mostly) hex tiling
4.     /// This is basically our triangle mesh that we draw hexes on.
5.     /// </summary>
6.      public struct HexTri
7.     {
8.        public int vertA;                                                        // HexA, indices into the Hextile array
9.         public int vertB;                                                       // HexB, indices into the Hextile array
10.         public int vertC;                                                       // HexC, indices into the Hextile array
11.         public int centerVertex;                                           // Center, indices into the Hextile array
12.         public int neighborsAccrossAB;                              // HexA, indices into the HexTri array
13.         public int neighborsAccrossBC;                              // HexA, indices into the HexTri array
14.         public int neighborsAccrossCA;                              // HexA, indices into the HexTri array
15.     }
16.  

Code (csharp):

1.  
2.     /// <summary>
3.     /// HexTile - A Hextile is a single hex (or sometimes pentagon)
4.     /// in the hex tiled planet. It is a single vertex of the mesh
5.     /// </summary>
6.     public struct HexVert
7.     {
8.         public float positionX;                                                 // World X space of this HexTile
9.         public float positionY;                                                 // World Y space of this HexTile
10.         public float positionZ;                                                 // World Z space of this HexTile
11.         public int connectedTriA;                                               //Index into the HexTri array that share this hex
12.         public int connectedTriB;                                               //Index into the HexTri array that share this hex
13.         public int connectedTriC;                                               //Index into the HexTri array that share this hex
14.         public int connectedTriD;                                               //Index into the HexTri array that share this hex
15.         public int connectedTriE;                                               //Index into the HexTri array that share this hex
16.         public int connectedTriF;                                               //Index into the HexTri array that share this hex
17.         #endregion
18.  
19.     }
20.  
21.  

Code (csharp):

1.  
2.     /// <summary>
3.     /// Main class for building the HexSphere system.
4.     /// </summary>
5.     public class HexSphereSystemBuild
6.     {
7.         #region FIELDS ---------------------------------------------------------
8.  
9.         public HexVert[] hexVerticies;                                               // The hexes or verts ( center of hexegon)
10.         public HexTri[] hexTriangles;                                                // The triangles around a hex ( hexegon )
11.  
12.         #endregion
13. ............
14.  

Phase 1
The fist step is to get my hexSphere subdivision working using ECS. So Im starting small by trying to store my subdivisionLevel 0 positions in entities. Im brand new at ECS but want to do this right.

Goal


Here is my component date ported form the old struct HexVert. Ive added a index and subdivision. In my old system the int HexTri.neighborsAccrossAB was an index into HexVert. So maybe this should now be public Entity;

Code (csharp):

1.  
2.     /// <summary>
3.     /// HexTile - A Hextile is a single hex (or sometimes pentagon)
4.     /// in the hex tiled planet. It is a single vertex of the mesh
5.     /// </summary>
6.  
7.     public struct VertexComponent : IComponentData
8.     {
9.         #region FLIELDS --------------------------------------------------------
10.  
11.         public int index;
12.         public float3 position;
13.  
14.         #endregion
15.  
16.     }
17.  
18.     public struct VertexTrianglesComponent : IComponentData
19.     {
20.         #region FLIELDS --------------------------------------------------------
21.  
22.         public int connectedTriA;                                               //Index into the HexTri array that share this hex
23.         public int connectedTriB;                                               //Index into the HexTri array that share this hex
24.         public int connectedTriC;                                               //Index into the HexTri array that share this hex
25.         public int connectedTriD;                                               //Index into the HexTri array that share this hex
26.         public int connectedTriE;                                               //Index into the HexTri array that share this hex
27.         public int connectedTriF;                                               //Index into the HexTri array that share this hex
28.  
29.         #endregion
30.  
31.     }
32.  
33.     public struct VertexSubdivisionComponent : IComponentData
34.     {
35.         #region FLIELDS --------------------------------------------------------
36.  
37.         public int divisionLevel;
38.  
39.         #endregion
40.  
41.     }
42.  
43.  

Here is my attempt at storing data into my tileEntities. Im having two problmes.
1) How do I index this
2) How do I get my Icosahedron data into an entity.

Code (csharp):

1.  
2.     public struct IcosahedronComponent : IComponentData
3.     {
4.         #region FLIELDS --------------------------------------------------------
5.  
6.         public static float[] posVtxX = { 0.723606f, 0.0f, -0.723606f, 0.0f, 0.723606f, 0.0f, -0.723606f, 0.0f, 1.17082f, 1.17082f, -1.17082f ,-1.17082f };
7.         public static float[] posVtxY = { 0.0f, 1.17082f, 0.0f, -1.17082f, 0.0f, -1.17082f, 0.0f, 1.17082f, -0.723606f, 0.723606f, 0.723606f, -0.723606f };
8.         public static float[] posVtxZ = { 1.17082f, 0.723606f, 1.17082f, 0.723606f, -1.17082f, -0.723606f, -1.17082f, -0.723606f, 0.0f, 0.0f, 0.0f, 0.0f };
9.  
10.         #endregion
11.  
12.     }
13.  
14.  

Code (csharp):

1.  
2.         protected override void OnCreateManager()
3.         {
4.             //
5.             // Create Archetype
6.             tileArchetype = EntityManager.CreateArchetype
7.                 (
8.                 typeof(VertexComponent),
9.                 typeof(VertexTrianglesComponent),
10.                 typeof(VertexSubdivisionComponent)
11.                 );
12.  
13.             //
14.             // Create Entities
15.             EntityManager.CreateEntity( typeof(IcosahedronComponent) );
16.  
17.             //
18.             // Build Icosahedron
19.             BuildIcosahedronEntities(1.0f);
20.         }
21.  
22.         /// <summary>
23.         /// Create the lvl 0 Icosahedron.
24.         /// </summary>
25.         private void BuildIcosahedronEntities(float raduis)
26.         {
27.             //
28.             // Create first 12 entities for Icosahedron.
29.             /// </summary>
30.             NativeArray<Entity> entityArray = new NativeArray<Entity>(12, Allocator.Temp);
31.             EntityManager.CreateEntity(tileArchetype, entityArray );
32.             _query = GetEntityQuery(typeof(VertexSubdivisionComponent), typeof(VertexComponent));
33.             Entities.With(_query).ForEach<VertexSubdivisionComponent, VertexComponent, VertexTrianglesComponent, IcosahedronComponent>((ref VertexSubdivisionComponent vtxSubDiv, ref VertexComponent vtx, ref VertexTrianglesComponent vtxTri, ref IcosahedronComponent icosahedronData) => {
34.                 vtxTri.connectedTriA = -1;
35.                 vtxTri.connectedTriB = -1;
36.                 vtxTri.connectedTriC = -1;
37.                 vtxTri.connectedTriD = -1;
38.                 vtxTri.connectedTriE = -1;
39.                 vtxTri.connectedTriF = -1;
40.                 vtxSubDiv.divisionLevel = 0;
41.                 vtx.index =  ??; i++ // not sure what to do here !!!!!!!!!!!!!!!!
42.                 vtx.position = ?? // Lost as hell !!!!!!!!!!!!!!!
43.             });
44. }
45.  

Any help would be appreciate Im trying to get back to where I left off but using ECS

 

Is it best to just initialize the entities with the Icosahedron one by one not in a ForEach loop

 

Best way to initialize large groups of entities usually is with

EntityManager.CreateEntity(EntityArchetype archetype, NativeArray<Entity> entities)

 

Im having a really tough time here lol. Thank you for the reply

Can I ask you for a simple example on how do get existing data into the Entity using Entities.With(_query).ForEach
. So for my example I have an array or struct of data I want store into my entities. (Sorry this is really basic stuff but I really want to grasp the concepts of ECS)

here is what I would normally do

Code (csharp):

1.  
2.  
3.     public struct VertexComponent
4.     {
5.         public int index;
6.         public float3 position;
7.     }
8.  
9.     hexVerticies = new VertexComponen[12];
10.     for (int i = 0; i<12; i++)
11.     {
12.         hexVerticies[i].index = i;
13.         hexVerticies[i].position.x = posVtxX[i].x
14.         ...
15.     }
16.  
17.  

How would I do it the awesome ECS way

 

Ok did it brute force but there surely must be a better way

Code (csharp):

1.  
2.     /// <summary>
3.     /// System for creating a hexSphere
4.     /// </summary>
5.     public class HexSphereBuildSystem : ComponentSystem
6.     {
7.         #region FIELDS ---------------------------------------------------------
8.  
9.         public static EntityArchetype tileArchetype;
10.         EntityQuery _query;
11.  
12.         #endregion
13.  
14.  
15.         #region METHODS --------------------------------------------------------
16.  
17.         /// <summary>
18.         /// OnUpdate, Must implement for ComponentSystem
19.         /// </summary>
20.         protected override void OnUpdate()
21.         {
22.             Debug.Log("In system");
23.         }
24.  
25.         /// <summary>
26.         /// OnCreateManager
27.         /// </summary>
28.         protected override void OnCreateManager()
29.         {
30.             //
31.             // Create Archetype
32.             tileArchetype = EntityManager.CreateArchetype
33.                 (
34.                 typeof(VertexComponent),
35.                 typeof(VertexTrianglesComponent),
36.                 typeof(VertexSubdivisionComponent)
37.                 );
38.  
39.             //
40.             // Build Icosahedron
41.             BuildIcosahedronEntities(1.0f);
42.         }
43.  
44.         /// <summary>
45.         /// Create the lvl 0 Icosahedron.
46.         /// </summary>
47.         private void BuildIcosahedronEntities(float raduis)
48.         {
49.  
50.             //
51.             // Hard code an icosahedron verticies (20 sided die)
52.  
53.             Entity tileEntity = EntityManager.CreateEntity(tileArchetype);
54.             EntityManager.SetComponentData(tileEntity, new VertexComponent { index = 0, position = new float3(0.723606f, 0.0f, 1.17082f) });
55.             EntityManager.SetComponentData(tileEntity, new VertexTrianglesComponent { connectedTriA = -1, connectedTriB = -1, connectedTriC = -1, connectedTriD = -1, connectedTriE = -1, connectedTriF = -1 });
56.             EntityManager.SetComponentData(tileEntity, new VertexSubdivisionComponent {divisionLevel = 0 });
57.  
58.             tileEntity = EntityManager.CreateEntity(tileArchetype);
59.             EntityManager.SetComponentData(tileEntity, new VertexComponent { index = 1, position = new float3(0.0f, 1.17082f, 0.723606f) });
60.             EntityManager.SetComponentData(tileEntity, new VertexTrianglesComponent { connectedTriA = -1, connectedTriB = -1, connectedTriC = -1, connectedTriD = -1, connectedTriE = -1, connectedTriF = -1 });
61.             EntityManager.SetComponentData(tileEntity, new VertexSubdivisionComponent { divisionLevel = 0 });
62.  
63.             tileEntity = EntityManager.CreateEntity(tileArchetype);
64.             EntityManager.SetComponentData(tileEntity, new VertexComponent { index = 2, position = new float3(-0.723606f, 0.0f, 1.17082f) });
65.             EntityManager.SetComponentData(tileEntity, new VertexTrianglesComponent { connectedTriA = -1, connectedTriB = -1, connectedTriC = -1, connectedTriD = -1, connectedTriE = -1, connectedTriF = -1 });
66.             EntityManager.SetComponentData(tileEntity, new VertexSubdivisionComponent { divisionLevel = 0 });
67.  
68.             tileEntity = EntityManager.CreateEntity(tileArchetype);
69.             EntityManager.SetComponentData(tileEntity, new VertexComponent { index = 3, position = new float3(0.0f, -1.17082f, 0.723606f) });
70.             EntityManager.SetComponentData(tileEntity, new VertexTrianglesComponent { connectedTriA = -1, connectedTriB = -1, connectedTriC = -1, connectedTriD = -1, connectedTriE = -1, connectedTriF = -1 });
71.             EntityManager.SetComponentData(tileEntity, new VertexSubdivisionComponent { divisionLevel = 0 });
72.  
73.             tileEntity = EntityManager.CreateEntity(tileArchetype);
74.             EntityManager.SetComponentData(tileEntity, new VertexComponent { index = 4, position = new float3(0.723606f, 0.0f, -1.17082f) });
75.             EntityManager.SetComponentData(tileEntity, new VertexTrianglesComponent { connectedTriA = -1, connectedTriB = -1, connectedTriC = -1, connectedTriD = -1, connectedTriE = -1, connectedTriF = -1 });
76.             EntityManager.SetComponentData(tileEntity, new VertexSubdivisionComponent { divisionLevel = 0 });
77.  
78.             tileEntity = EntityManager.CreateEntity(tileArchetype);
79.             EntityManager.SetComponentData(tileEntity, new VertexComponent { index = 5, position = new float3(0.0f, -1.17082f, -0.723606f) });
80.             EntityManager.SetComponentData(tileEntity, new VertexTrianglesComponent { connectedTriA = -1, connectedTriB = -1, connectedTriC = -1, connectedTriD = -1, connectedTriE = -1, connectedTriF = -1 });
81.             EntityManager.SetComponentData(tileEntity, new VertexSubdivisionComponent { divisionLevel = 0 });
82.            
83.            tileEntity = EntityManager.CreateEntity(tileArchetype);
84.             EntityManager.SetComponentData(tileEntity, new VertexComponent { index = 6, position = new float3(-0.723606f, 0.0f, -1.17082f) });
85.             EntityManager.SetComponentData(tileEntity, new VertexTrianglesComponent { connectedTriA = -1, connectedTriB = -1, connectedTriC = -1, connectedTriD = -1, connectedTriE = -1, connectedTriF = -1 });
86.             EntityManager.SetComponentData(tileEntity, new VertexSubdivisionComponent { divisionLevel = 0 });
87.  
88.             tileEntity = EntityManager.CreateEntity(tileArchetype);
89.             EntityManager.SetComponentData(tileEntity, new VertexComponent { index = 7, position = new float3(0.0f, 1.17082f, -0.723606f) });
90.             EntityManager.SetComponentData(tileEntity, new VertexTrianglesComponent { connectedTriA = -1, connectedTriB = -1, connectedTriC = -1, connectedTriD = -1, connectedTriE = -1, connectedTriF = -1 });
91.             EntityManager.SetComponentData(tileEntity, new VertexSubdivisionComponent { divisionLevel = 0 });
92.  
93.             tileEntity = EntityManager.CreateEntity(tileArchetype);
94.             EntityManager.SetComponentData(tileEntity, new VertexComponent { index = 8, position = new float3(1.17082f, -0.723606f, 0.0f) });
95.             EntityManager.SetComponentData(tileEntity, new VertexTrianglesComponent { connectedTriA = -1, connectedTriB = -1, connectedTriC = -1, connectedTriD = -1, connectedTriE = -1, connectedTriF = -1 });
96.             EntityManager.SetComponentData(tileEntity, new VertexSubdivisionComponent { divisionLevel = 0 });
97.  
98.             tileEntity = EntityManager.CreateEntity(tileArchetype);
99.             EntityManager.SetComponentData(tileEntity, new VertexComponent { index = 9, position = new float3(1.17082f, 0.723606f, 0.0f) });
100.             EntityManager.SetComponentData(tileEntity, new VertexTrianglesComponent { connectedTriA = -1, connectedTriB = -1, connectedTriC = -1, connectedTriD = -1, connectedTriE = -1, connectedTriF = -1 });
101.             EntityManager.SetComponentData(tileEntity, new VertexSubdivisionComponent { divisionLevel = 0 });
102.  
103.             tileEntity = EntityManager.CreateEntity(tileArchetype);
104.             EntityManager.SetComponentData(tileEntity, new VertexComponent { index = 10, position = new float3(-1.17082f, 0.723606f, 0.0f) });
105.             EntityManager.SetComponentData(tileEntity, new VertexTrianglesComponent { connectedTriA = -1, connectedTriB = -1, connectedTriC = -1, connectedTriD = -1, connectedTriE = -1, connectedTriF = -1 });
106.             EntityManager.SetComponentData(tileEntity, new VertexSubdivisionComponent { divisionLevel = 0 });
107.  
108.             tileEntity = EntityManager.CreateEntity(tileArchetype);
109.             EntityManager.SetComponentData(tileEntity, new VertexComponent { index = 11, position = new float3(-1.17082f, -0.723606f, 0.0f) });
110.             EntityManager.SetComponentData(tileEntity, new VertexTrianglesComponent { connectedTriA = -1, connectedTriB = -1, connectedTriC = -1, connectedTriD = -1, connectedTriE = -1, connectedTriF = -1 });
111.             EntityManager.SetComponentData(tileEntity, new VertexSubdivisionComponent { divisionLevel = 0 });
112.  
113.  
114.             //
115.             // Hard code an icosahedron triangles (20 sided die)
116.  
117.         }
118.  
119.         #endregion
120.  
121.     }
122.  
123.