private void Awake()
{
Instance = this;
EntityManager entityManager = World.DefaultGameObjectInjectionWorld.EntityManager;
EntityArchetype boidArchetype = entityManager.CreateArchetype(
typeof(BoidECS),
typeof(RenderMesh),
typeof(RenderBounds),
typeof(LocalToWorld)
);
NativeArray <Entity> boidArray = new NativeArray <Entity>(boidAmount, Allocator.Temp);
entityManager.CreateEntity(boidArchetype, boidArray);
for (int i = 0; i < boidArray.Length; i++)
{
Unity.Mathematics.Random rand = new Unity.Mathematics.Random((uint)i + 1);
entityManager.SetComponentData(boidArray[i], new LocalToWorld {
Value = float4x4.TRS(
RandomPosition(),
RandomRotation(),
new float3(1f))
});
entityManager.SetSharedComponentData(boidArray[i], new RenderMesh {
mesh = sharedMesh,
material = sharedMaterial,
});
}
boidArray.Dispose();
}
protected override void OnUpdate()
{
// This runs only if there exists a BoidControllerECS instance.
if (!controller)
{
controller = BoidControllerECS.Instance;
}
if (controller)
{
EntityQuery boidQuery = GetEntityQuery(ComponentType.ReadOnly <BoidECS>(), ComponentType.ReadOnly <LocalToWorld>());
NativeArray <float4x4> newBoidPositions = new NativeArray <float4x4>(boidQuery.CalculateEntityCount(), Allocator.Temp);
int boidIndex = 0;
Entities.WithAll <BoidECS>().ForEach((Entity boid, ref LocalToWorld localToWorld) => {
float3 boidPosition = localToWorld.Position;
float3 seperationSum = float3.zero;
float3 positionSum = float3.zero;
float3 headingSum = float3.zero;
int boidsNearby = 0;
Entities.WithAll <BoidECS>().ForEach((Entity otherBoid, ref LocalToWorld otherLocalToWorld) => {
if (boid != otherBoid)
{
float distToOtherBoid = math.length(boidPosition - otherLocalToWorld.Position);
if (distToOtherBoid < controller.boidPerceptionRadius)
{
seperationSum += -(otherLocalToWorld.Position - boidPosition) * (1f / math.max(distToOtherBoid, .0001f));
positionSum += otherLocalToWorld.Position;
headingSum += otherLocalToWorld.Forward;
boidsNearby++;
}
}
});
float3 force = float3.zero;
if (boidsNearby > 0)
{
force += (seperationSum / boidsNearby) * controller.separationWeight;
force += ((positionSum / boidsNearby) - boidPosition) * controller.cohesionWeight;
force += (headingSum / boidsNearby) * controller.alignmentWeight;
}
if (math.min(math.min(
(controller.cageSize / 2f) - math.abs(boidPosition.x),
(controller.cageSize / 2f) - math.abs(boidPosition.y)),
(controller.cageSize / 2f) - math.abs(boidPosition.z))
< controller.avoidWallsTurnDist)
{
force += -math.normalize(boidPosition) * controller.avoidWallsWeight;
}
float3 velocity = localToWorld.Forward * controller.boidSpeed;
velocity += force * Time.DeltaTime;
velocity = math.normalize(velocity) * controller.boidSpeed;
newBoidPositions[boidIndex] = float4x4.TRS(
localToWorld.Position + velocity * Time.DeltaTime,
quaternion.LookRotationSafe(velocity, localToWorld.Up),
new float3(1f)
);
boidIndex++;
});
boidIndex = 0;
Entities.WithAll <BoidECS>().ForEach((Entity boid, ref LocalToWorld localToWorld) => {
localToWorld.Value = newBoidPositions[boidIndex];
boidIndex++;
});
}
}
