protected override void OnUpdate()
{
EntityCommandBuffer ecb = new EntityCommandBuffer(Allocator.TempJob);
NativeArray <Entity> renderers = m_ParticleRenderersQuery.ToEntityArray(Allocator.TempJob);
foreach (var renderer in renderers)
{
var emitterReference = EntityManager.GetComponentData <EmitterReferenceForRenderer>(renderer);
var eEmitter = emitterReference.emitter;
// In some cases it takes an extra frame for the particle entities that reference a destroyed emitter to be destroyed, most likely because of system state components
if (!ParticlesUtil.EmitterIsValid(EntityManager, eEmitter))
{
continue;
}
DynamicBuffer <Particle> particles = EntityManager.GetBuffer <DynamicParticle>(eEmitter).Reinterpret <Particle>();
if (!EntityManager.GetEnabled(eEmitter) || particles.Length == 0)
{
if (!EntityManager.HasComponent <Disabled>(renderer))
{
ecb.AddComponent(renderer, new Disabled());
}
continue;
}
if (EntityManager.HasComponent <Disabled>(renderer))
{
ecb.RemoveComponent <Disabled>(renderer);
}
var particleMesh = EntityManager.GetComponentData <ParticleMesh>(eEmitter);
var meshRenderer = EntityManager.GetComponentData <MeshRenderer>(renderer);
Entity eMesh = meshRenderer.mesh;
var particleEmitter = EntityManager.GetComponentData <ParticleEmitter>(eEmitter);
var localToWorldEmitter = particleEmitter.AttachToEmitter ? EntityManager.GetComponentData <LocalToWorld>(eEmitter).Value : float4x4.identity;
MinMaxAABB minMaxAABB = MinMaxAABB.Empty;
int numVertices, numIndices;
if (EntityManager.HasComponent <LitParticleRenderer>(renderer))
{
ref LitMeshData lmd = ref EntityManager.GetComponentData <LitMeshRenderData>(particleMesh.Mesh).Mesh.Value;
int numVertsPerParticle = lmd.Vertices.Length;
int numIndicesPerParticle = lmd.Indices.Length;
NativeArray <LitVertex> particleVertices = MeshHelper.AsNativeArray(ref lmd.Vertices);
NativeArray <ushort> particleIndices = MeshHelper.AsNativeArray(ref lmd.Indices);
var vBuffer = EntityManager.GetBuffer <DynamicLitVertex>(eMesh);
var iBuffer = EntityManager.GetBuffer <DynamicIndex>(eMesh);
numVertices = particles.Length * numVertsPerParticle;
numIndices = particles.Length * numIndicesPerParticle;
vBuffer.ResizeUninitialized(numVertices); // Grow buffers as needed
iBuffer.ResizeUninitialized(numIndices);
NativeArray <LitVertex> vertices = vBuffer.AsNativeArray().Reinterpret <DynamicLitVertex, LitVertex>();
NativeArray <ushort> indices = iBuffer.AsNativeArray().Reinterpret <DynamicIndex, ushort>();
bool billboarded = EntityManager.GetComponentData <LitMaterial>(meshRenderer.material).billboarded;
for (int particleIndex = 0; particleIndex < particles.Length; particleIndex++)
{
float4x4 localToWorld = GetParticleLocalToWorld(particles[particleIndex], localToWorldEmitter);
float3x3 localToWorldRS = new float3x3(localToWorld.c0.xyz, localToWorld.c1.xyz, localToWorld.c2.xyz);
float3x3 modelInverseTransposeRS = math.transpose(math.inverse(localToWorldRS));
float4x4 modelInverseTranspose = new float4x4(modelInverseTransposeRS, float3.zero);
// Postpone translate until after additional rotation for billboarding is applied in shader
float4x4 model = billboarded ? new float4x4(localToWorldRS, float3.zero) : localToWorld;
int vertexOffset = particleIndex * numVertsPerParticle;
for (int i = 0; i < numVertsPerParticle; i++)
{
LitVertex vertex = particleVertices[i];
vertex.Position = math.transform(model, vertex.Position);
vertex.Normal = math.transform(modelInverseTranspose, vertex.Normal);
vertex.Tangent = math.transform(modelInverseTranspose, vertex.Tangent);
vertex.BillboardPos = billboarded ? localToWorld.c3.xyz : float3.zero;
vertex.Albedo_Opacity = particles[particleIndex].color;
vertices[vertexOffset + i] = vertex;
minMaxAABB.Encapsulate(vertex.Position + vertex.BillboardPos);
}
UpdateIndicesForParticle(indices, particleIndices, particleIndex, numIndicesPerParticle, vertexOffset);
}
}
