Assets/Shaders/ParticleEmit_CS.glsl

@@ -7,7 +7,7 @@ struct EmitterParameters
   vec4 angularMin;
   vec4 angularMax;
   vec4 lifeAndSizeRange; // min life, max life, min size, max size
-}
+};
 
 struct ParticleData
 {
@@ -18,7 +18,7 @@ struct ParticleData
   vec4 scaleAndDecay;
   float life;
   uint textureIndex;
-}
+};
 
 struct GenericData
 {
@@ -96,9 +96,15 @@ float rand(inout uint state)
   return float(x)*uintBitsToFloat(0x2f800004u);
 }
 
+float map(float value, float inMin, float inMax, float outMin, float outMax) 
+{
+  return outMin + (outMax - outMin) * (value - inMin) / (inMax - inMin);
+}
+
 void main()
 { 
   uint emitterInvocationIndex = gl_GlobalInvocationID.x;
+  vec4 emitterPosition = emitterPushConstant.emitterPosition;
 
   if (emitterInvocationIndex >= emitterPushConstant.emissionCount)
     return;
@@ -109,9 +115,18 @@ void main()
 
   ParticleData particle;
 
-  int index = freelist.freeIndices[freelistIndex];
-  particle.position = emitterPosition;
-  particle.life = emitterParams.10.0f;
+  // Get seed for randomization
+  uint pixel_index = uint (emitterPosition.x + emitterPosition.y + floatBitsToUint(genericDataBuffer.data.elapsedTime) * (gl_GlobalInvocationID.x + 1));
+  uint seed = pcg_hash (pixel_index);
 
-  particles[index] = particle;
+  int index = freelist.freeIndices[freelistIndex];
+
+  // emit particle from emitter position
+  particle.position = vec4 (emitterPosition.xyz, 1.0f);
+
+  // randomize life value that ranges from minLife to maxLife
+  particle.life = map (rand(seed), -1.0f, 1.0f, emitterParams.data.lifeAndSizeRange.x, emitterParams.data.lifeAndSizeRange.y);
+
+
+  inputParticles.data[index] = particle;
 }

Assets/Shaders/ParticleEmit_CS.shshaderb.shmeta

@@ -0,0 +1,3 @@
+Name: ParticleEmit_CS
+ID: 49959611
+Type: 2

Assets/Shaders/ParticleUpdate_CS.glsl

@@ -19,7 +19,7 @@ struct ParticleData
   vec4 scaleAndDecay;
   float life;
   uint textureIndex;
-}
+};
 
 struct GenericData
 {
@@ -73,7 +73,7 @@ layout (std430, set = 2, binding = 4) coherent restrict buffer IndicesData
   uint indices[];
 };
 
-layout (std140, set = 2, binding = 5) coherent restrict uniform IndirectDrawArgs
+layout (std140, set = 2, binding = 5) coherent restrict buffer IndirectDrawArgs
 {
   DrawArraysIndirectArgs indirectArgs;
 }; 
@@ -116,17 +116,12 @@ void main()
 
   ParticleData particle = inputParticles.data[index];
 
-  if (particle.lifetime > 0.0f)
+  if (particle.life > 0.0f)
   {
-    // particle.position += particle.velocity * dt;
     
-    // particle.lifetime -= dt;
-    // particle.size -= 1.2f * dt;
-    // particle.color += 1.0f * dt;
-    
-    if (particle.lifetime < 0.0f || particle.size < 0.0f)
+    if (particle.life < 0.0f || particle.scaleAndDecay.x < 0.0f || particle.scaleAndDecay.y < 0.0f)
     {
-      particle.lifetime = 0.0f;
+      particle.life = 0.0f;
       particle.position.x = 99999.0f;
       
       outputParticles.data[index] = particle;

Assets/Shaders/ParticleUpdate_CS.shshaderb.shmeta

@@ -0,0 +1,3 @@
+Name: ParticleUpdate_CS
+ID: 36260925
+Type: 2

Assets/Shaders/Particle_FS.glsl

@@ -0,0 +1,15 @@
+#version 460 core
+
+layout (location = 0) out vec4 fragColor;
+
+// between shader stages
+layout(location = 0) in struct
+{
+  vec2 uv; // location = 0
+
+} In;
+
+void main ()
+{
+	fragColor = vec4 (1.0f);
+}

Assets/Shaders/Particle_FS.shshaderb.shmeta

@@ -0,0 +1,3 @@
+Name: Particle_FS
+ID: 42509714
+Type: 2

Assets/Shaders/Particle_VS.glsl

@@ -0,0 +1,93 @@
+#version 460 core
+
+struct GenericData
+{
+  //! Delta time
+  float dt;
+
+  //! Elapsed time of the application
+  float elapsedTime;
+
+  //! Viewport width of the scene (excluding imgui, that means smaller than window)
+  uint viewportWidth;
+
+  //! Ditto but for height
+  uint viewportHeight;
+};
+
+
+struct ParticleData
+{
+  vec4 position;
+  vec4 rotation;
+  vec4 velocity;
+  vec4 acceleration;
+  vec4 scaleAndDecay;
+  float life;
+  uint textureIndex;
+};
+
+layout (set = 0, binding = 0) uniform GenericDataBuffer
+{
+  GenericData data;
+} genericDataBuffer;
+
+
+layout(set = 1, binding = 0) uniform CameraData
+{
+  vec4 position; 
+  mat4 vpMat;
+  mat4 viewMat;
+  mat4 projMat;
+} cameraData;
+
+// output buffer not needed
+layout (std430, set = 2, binding = 2) coherent restrict buffer ParticlesOutputBuffer
+{
+  ParticleData data[];
+} outputParticles;
+
+layout (std430, set = 2, binding = 4) coherent restrict buffer IndicesData
+{
+  uint indices[];
+};
+
+// between shader stages
+layout(location = 0) out struct
+{
+  vec2 uv; // location = 0
+
+} Out;
+
+vec2 CreateQuad (in uint vertexID)
+{
+  uint b = 1 << vertexID;
+  return vec2 ((0x3 & b) != 0, (0x9 & b) != 0);
+}
+
+void main()
+{
+  // Create a quad and its texture coordinates
+  Out.uv = CreateQuad (gl_VertexIndex);
+  vec3 vertexPos = vec3 (Out.uv - vec2(0.5f), 0.0f);
+
+  ParticleData particle = outputParticles.data[indices[gl_InstanceIndex]];
+
+  vec3 normalized = normalize (particle.velocity.xyz);
+	float angle = atan (normalized.y, normalized.x);
+  vec2 particleScaleData = particle.scaleAndDecay.xz; // x and y
+
+	mat4 localModel = mat4 (1.0f);
+  localModel[0][0] = particleScaleData.x;
+  localModel[1][1] = particleScaleData.y;
+
+  mat4 rotate = mat4(1.0f);
+	rotate[0][0] = cos(angle);
+  rotate[0][1] = sin(angle);
+  rotate[1][0] = -sin(angle);
+  rotate[1][1] = cos(angle);
+	localModel = rotate * localModel;
+
+	localModel[3] = vec4 (particle.position.xyz, 1.0f);
+  gl_Position = cameraData.vpMat * localModel * vec4(vertexPos, 1.0f);
+}

Assets/Shaders/Particle_VS.shshaderb.shmeta

@@ -0,0 +1,3 @@
+Name: Particle_VS
+ID: 35035037
+Type: 2

SHADE_Engine/src/Editor/EditorWindow/Inspector/SHEditorComponentView.hpp

@@ -30,6 +30,7 @@
 #include "../SHEditorWindowManager.h"
 #include "../AssetBrowser/SHAssetBrowser.h"
 #include "Graphics/MiddleEnd/TrajectoryRendering/SHTrajectoryRenderableComponent.h"
+#include "Graphics/MiddleEnd/Particles/SHParticleEmitterComponent.h"
 #include "Animation/SHAnimationClip.h"
 
 namespace SHADE
@@ -804,4 +805,32 @@ namespace SHADE
     ImGui::PopID();
   }
 
+  template<>
+  static void DrawComponent(SHParticleEmitterComponent* component)
+  {
+    if (!component)
+      return;
+
+    ImGui::PushID(SHFamilyID<SHComponent>::GetID<SHParticleEmitterComponent>());
+
+    const auto componentType = rttr::type::get(*component);
+
+    SHEditorWidgets::CheckBox("##IsActive", [component]() {return component->isActive; }, [component](bool const& active) {component->isActive = active; }, "Is Component Active");
+
+    ImGui::SameLine();
+    if (ImGui::CollapsingHeader(componentType.get_name().data(), ImGuiTreeNodeFlags_DefaultOpen))
+    {
+      DrawContextMenu(component);
+      
+      SHEditorWidgets::DragFloat("Emission Count", [comp = component]() {return comp->GetEmissionCount(); }, [comp = component](float count) {comp->SetEmissionCount(count);});
+      SHEditorWidgets::CheckBox("Is Passive", [comp = component]() {return comp->GetPassive(); }, [comp = component](bool flag) {comp->SetPassive(flag); });
+
+    }
+    else
+    {
+      DrawContextMenu(component);
+    }
+    ImGui::PopID();
+  }
+
 }

SHADE_Engine/src/Graphics/Commands/SHVkCommandBuffer.cpp

@@ -450,7 +450,7 @@ namespace SHADE
   */
   /***************************************************************************/
 
-  void SHVkCommandBuffer::DrawMultiIndirect(Handle<SHVkBuffer> indirectDrawData, uint32_t drawCount)
+  void SHVkCommandBuffer::DrawMultiIndirectIndexed(Handle<SHVkBuffer> indirectDrawData, uint32_t drawCount)
   {
     if (cmdBufferState != SH_CMD_BUFFER_STATE::RECORDING)
     {
@@ -462,6 +462,19 @@ namespace SHADE
       vkCommandBuffer.drawIndexedIndirect(indirectDrawData->GetVkBuffer(), 0, drawCount, sizeof(vk::DrawIndexedIndirectCommand));
   }
 
+  void SHVkCommandBuffer::DrawMultiIndirect(Handle<SHVkBuffer> indirectDrawData, uint32_t drawCount)
+  {
+    if (cmdBufferState != SH_CMD_BUFFER_STATE::RECORDING)
+    {
+      SHLOG_ERROR("Command buffer must have started recording before a pipeline can be bound.");
+      return;
+    }
+
+    if (indirectDrawData)
+      vkCommandBuffer.drawIndirect(indirectDrawData->GetVkBuffer(), 0, drawCount, sizeof(vk::DrawIndexedIndirectCommand));
+
+  }
+
   void SHVkCommandBuffer::ComputeDispatch(uint32_t groupCountX, uint32_t groupCountY, uint32_t groupCountZ) noexcept
   {
     vkCommandBuffer.dispatch (groupCountX, groupCountY, groupCountZ);

SHADE_Engine/src/Graphics/Commands/SHVkCommandBuffer.h

@@ -130,6 +130,7 @@ namespace SHADE
     // Draw Commands
     void DrawArrays                (uint32_t vertexCount, uint32_t instanceCount, uint32_t firstVertex, uint32_t firstInstance) const noexcept;
     void DrawIndexed               (uint32_t indexCount, uint32_t firstIndex, uint32_t vertexOffset) const noexcept;
+    void DrawMultiIndirectIndexed  (Handle<SHVkBuffer> indirectDrawData, uint32_t drawCount);
     void DrawMultiIndirect         (Handle<SHVkBuffer> indirectDrawData, uint32_t drawCount);
 
     // Compute Commands

SHADE_Engine/src/Graphics/MiddleEnd/Batching/SHBatch.cpp

@@ -755,7 +755,7 @@ namespace SHADE
       }
 
     }
-    cmdBuffer->DrawMultiIndirect(drawDataBuffer[frameIndex], static_cast<uint32_t>(drawData.size()));
+    cmdBuffer->DrawMultiIndirectIndexed(drawDataBuffer[frameIndex], static_cast<uint32_t>(drawData.size()));
     cmdBuffer->EndLabeledSegment();
   }
 

SHADE_Engine/src/Graphics/MiddleEnd/GlobalData/SHGraphicsPredefinedData.cpp

@@ -251,7 +251,7 @@ namespace SHADE
     // particle draw call binding
     SHVkDescriptorSetLayout::Binding particleDrawDataBinding
     {
-      .Type = vk::DescriptorType::eUniformBufferDynamic, // UBO (Because lesser data), dynamic (1 set for each frame)
+      .Type = vk::DescriptorType::eStorageBufferDynamic, // UBO (Because lesser data), dynamic (1 set for each frame)
       .Stage = vk::ShaderStageFlagBits::eCompute,
       .BindPoint = SHGraphicsConstants::DescriptorSetBindings::PARTICLE_DRAW_DATA,
       .DescriptorCount = 1,

SHADE_Engine/src/Graphics/MiddleEnd/Interface/SHDebugDrawSystem.cpp

@@ -730,7 +730,7 @@ namespace SHADE
     cmdBuffer->BindVertexBuffer(COLOR_BIND_PT, batch.InstanceColorBuffer[frameIndex], 0);
 
     // Execute draw
-    cmdBuffer->DrawMultiIndirect(batch.MDIBuffer[frameIndex], static_cast<uint32_t>(batch.MDIData.size()));
+    cmdBuffer->DrawMultiIndirectIndexed(batch.MDIBuffer[frameIndex], static_cast<uint32_t>(batch.MDIData.size()));
   }
 
   void SHDebugDrawSystem::destroyBatch(MeshBatch& batch)

SHADE_Engine/src/Graphics/MiddleEnd/Interface/SHGraphicsSystem.cpp

@@ -144,6 +144,10 @@ namespace SHADE
     //SHAssetManager::CompileAsset("../../Assets/Shaders/Trajectory_FS.glsl", false);
     //SHAssetManager::CompileAsset("../../Assets/Shaders/ShadowMapBlur_CS.glsl", false);
     //SHAssetManager::CompileAsset("../../Assets/Shaders/Anim_VS.glsl", false);
+    SHAssetManager::CompileAsset("../../Assets/Shaders/Particle_VS.glsl", false);
+    SHAssetManager::CompileAsset("../../Assets/Shaders/Particle_FS.glsl", false);
+    SHAssetManager::CompileAsset("../../Assets/Shaders/ParticleEmit_CS.glsl", false);
+    SHAssetManager::CompileAsset("../../Assets/Shaders/ParticleUpdate_CS.glsl", false);
 
     // Load Built In Shaders
     static constexpr AssetID VS_DEFAULT         = 39210065;  defaultVertShader       = SHResourceManager::LoadOrGet<SHVkShaderModule>(VS_DEFAULT);
@@ -165,6 +169,9 @@ namespace SHADE
     static constexpr AssetID TRAJECTORY_VS      = 41042628;  trajectoryVS            = SHResourceManager::LoadOrGet<SHVkShaderModule>(TRAJECTORY_VS);
     static constexpr AssetID TRAJECTORY_FS      = 45635685;  trajectoryFS            = SHResourceManager::LoadOrGet<SHVkShaderModule>(TRAJECTORY_FS);
     static constexpr AssetID SHADOW_BLUR_CS     = 38004013;  shadowMapBlurCS         = SHResourceManager::LoadOrGet<SHVkShaderModule>(SHADOW_BLUR_CS);
+    static constexpr AssetID PARTICLE_VS        = 35035037;  particleVS              = SHResourceManager::LoadOrGet<SHVkShaderModule>(PARTICLE_VS);
+    static constexpr AssetID PARTICLE_EMIT_CS   = 42509714;  particleEmitCS          = SHResourceManager::LoadOrGet<SHVkShaderModule>(PARTICLE_EMIT_CS);
+    static constexpr AssetID PARTICLE_UPDATE_CS = 36260925;  particleUpdateCS        = SHResourceManager::LoadOrGet<SHVkShaderModule>(PARTICLE_UPDATE_CS);
 
   }
 

SHADE_Engine/src/Graphics/MiddleEnd/Interface/SHGraphicsSystem.h

@@ -484,6 +484,10 @@ namespace SHADE
     Handle<SHVkShaderModule>                                  trajectoryVS;
     Handle<SHVkShaderModule>                                  trajectoryFS;
     Handle<SHVkShaderModule>                                  shadowMapBlurCS;
+    Handle<SHVkShaderModule>                                  particleVS;
+    Handle<SHVkShaderModule>                                  particleFS;
+    Handle<SHVkShaderModule>                                  particleEmitCS;
+    Handle<SHVkShaderModule>                                  particleUpdateCS;
 
     // Fonts
     Handle<SHFont>                                            testFont;

SHADE_Engine/src/Graphics/MiddleEnd/Particles/SHParticleEmitterComponent.cpp

@@ -20,4 +20,24 @@ namespace SHADE
     toEmit = true;
   }
 
+  void SHParticleEmitterComponent::SetEmissionCount(float count) noexcept
+  {
+    emissionCount = count;
+  }
+
+  bool SHParticleEmitterComponent::SetPassive(bool flag) noexcept
+  {
+    isPassive = flag;
+  }
+
+  float SHParticleEmitterComponent::GetEmissionCount(void) noexcept
+  {
+    return emissionCount;
+  }
+
+  bool SHParticleEmitterComponent::GetPassive(void) noexcept
+  {
+    return isPassive;
+  }
+
 }

SHADE_Engine/src/Graphics/MiddleEnd/Particles/SHParticleEmitterComponent.h

@@ -105,6 +105,12 @@ namespace SHADE
 
     void Emit (void) noexcept;
 
+    void SetEmissionCount (float count) noexcept;
+    bool SetPassive       (bool flag) noexcept;
+
+    float GetEmissionCount (void) noexcept;
+    bool GetPassive (void) noexcept;
+
     friend class SHParticleSubSystem;
 
   };

SHADE_Engine/src/Graphics/MiddleEnd/Particles/SHParticleSubSystem.cpp

@@ -60,7 +60,7 @@ namespace SHADE
       }
 
       // buffer to store draw call data. Non-indexed, host-visible mapped, triple buffered. 
-      comp.drawCallData = logicalDevice->CreateBuffer(SHGraphicsConstants::NUM_FRAME_BUFFERS * sizeofIndirectCmd, indirectCommands.data(), SHGraphicsConstants::NUM_FRAME_BUFFERS * sizeofIndirectCmd, vk::BufferUsageFlagBits::eUniformBuffer | vk::BufferUsageFlagBits::eIndirectBuffer, VMA_MEMORY_USAGE_AUTO, VmaAllocationCreateFlagBits::VMA_ALLOCATION_CREATE_HOST_ACCESS_SEQUENTIAL_WRITE_BIT | VmaAllocationCreateFlagBits::VMA_ALLOCATION_CREATE_MAPPED_BIT);
+      comp.drawCallData = logicalDevice->CreateBuffer(SHGraphicsConstants::NUM_FRAME_BUFFERS * sizeofIndirectCmd, indirectCommands.data(), SHGraphicsConstants::NUM_FRAME_BUFFERS * sizeofIndirectCmd, vk::BufferUsageFlagBits::eStorageBuffer | vk::BufferUsageFlagBits::eIndirectBuffer, VMA_MEMORY_USAGE_AUTO, VmaAllocationCreateFlagBits::VMA_ALLOCATION_CREATE_HOST_ACCESS_SEQUENTIAL_WRITE_BIT | VmaAllocationCreateFlagBits::VMA_ALLOCATION_CREATE_MAPPED_BIT);
 
     }
 
@@ -150,6 +150,59 @@ namespace SHADE
 
   void SHParticleSubSystem::RenderComponent(Handle<SHVkCommandBuffer> cmdBuffer, SHParticleEmitterComponent& comp, uint32_t frameIndex) noexcept
   {
+    cmdBuffer->DrawMultiIndirect(comp.drawCallData, 1);
+  }
+
+  void SHParticleSubSystem::PreparePrePostUpdateBarriers(std::vector<vk::BufferMemoryBarrier>& preUpdateBarriers, std::vector<vk::BufferMemoryBarrier>& postUpdateBarriers, SHParticleEmitterComponent const& emitter, uint32_t const EMITTER_INDEX, uint32_t const FRAME_INDEX) noexcept
+  {
+    // pre-update particles data barrier. Note that this is for input because we want the input to be available before we use it.
+    vk::BufferMemoryBarrier particleDataBarrier
+    {
+      .srcAccessMask = vk::AccessFlagBits::eShaderWrite,
+      .dstAccessMask = vk::AccessFlagBits::eShaderRead,
+      .buffer = emitter.particleData->GetVkBuffer(),
+      .offset = emitter.dynamicOffsets[FRAME_INDEX][DYOFF_INDEX_PARTICLE_INPUT],
+      .size = emitter.chunkSize
+    };
+
+    // pre-update free list data barrier
+    vk::BufferMemoryBarrier freelistDataBarrier
+    {
+      .srcAccessMask = vk::AccessFlagBits::eShaderWrite,
+      .dstAccessMask = vk::AccessFlagBits::eShaderRead,
+      .buffer = emitter.freelistData->GetVkBuffer(),
+      .offset = 0, // Only 1 copy of freelist data, so offset is at 0
+      .size = static_cast<uint32_t>(sizeof (uint32_t)) * (emitter.maxParticles + 1)
+    };
+
+    // ...copy assign barriers on heap 
+    preUpdateBarriers[EMITTER_INDEX * 2] = particleDataBarrier;
+    preUpdateBarriers[(EMITTER_INDEX * 2) + 1] = freelistDataBarrier;
+
+    // make new barrier on stack...
+    vk::BufferMemoryBarrier particleDataBarrierPost
+    {
+      .srcAccessMask = vk::AccessFlagBits::eShaderWrite,
+      .dstAccessMask = vk::AccessFlagBits::eShaderRead,
+      .buffer = emitter.particleData->GetVkBuffer(),
+      .offset = emitter.dynamicOffsets[FRAME_INDEX][DYOFF_INDEX_PARTICLE_OUTPUT],
+      .size = emitter.chunkSize
+    };
+
+    // make new barrier on stack...
+    vk::BufferMemoryBarrier indicesDataBarrier
+    {
+      .srcAccessMask = vk::AccessFlagBits::eShaderWrite,
+      .dstAccessMask = vk::AccessFlagBits::eShaderRead,
+      .buffer = emitter.indicesData->GetVkBuffer(),
+      .offset = emitter.dynamicOffsets[FRAME_INDEX][DYOFF_INDEX_INDICES_DATA],
+      .size = static_cast<uint32_t>(sizeof(uint32_t)) * emitter.maxParticles 
+    };
+
+
+    // ...copy assign barriers on heap 
+    postUpdateBarriers[EMITTER_INDEX * 2] = particleDataBarrierPost;
+    postUpdateBarriers[(EMITTER_INDEX * 2) + 1] = indicesDataBarrier;
 
   }
 
@@ -203,10 +256,19 @@ namespace SHADE
     // Get offset into GPU emitter data (for updating)
     uint32_t emitterDataOffset = frameIndex * sizeof (SHParticleEmitterComponent::GPUEmitterStruct);
     
+    // TODO: OPTIONAL but eventually these barriers can be moved to the system as member variables. This would require additional bookkeeping
+    // but it will be more efficient than populating a vector every frame.
+
     // Barriers to make sure emitting shader is done completely before update is run.
-    // Every emitter will have its own barrier.
+    // Every emitter will have its own barrier for its particle data and freelist data. Indices data is not needed since
+    // it's mainly used in update and rendering so a barrier for it is NOT needed here.
     std::vector<vk::BufferMemoryBarrier> preUpdateBarriers{};
-    preUpdateBarriers.resize(emitters.size());
+    preUpdateBarriers.resize(emitters.size() * 2);
+
+    // After we invoke the updates for the emitters, we need to make sure all particles and indices data are done updating
+    // before we issue them for rendering. 
+    std::vector<vk::BufferMemoryBarrier> postUpdateBarriers{};
+    postUpdateBarriers.resize(emitters.size() * 2);
 
     // If we wanted to be VERY safe, a barrier would be good here to make sure output particles have finish reading input particles in 
     // the update compute. HOWEVER since a NUM_FRAME_BUFFERS frames would have passed by then, we will not insert 1 here.
@@ -255,19 +317,10 @@ namespace SHADE
         EmitComponent(cmdBuffer, emitter, frameIndex);
       }
 
-      // make new barrier on stack...
-      vk::BufferMemoryBarrier barrier
-      {
-        .srcAccessMask = vk::AccessFlagBits::eShaderWrite,
-        .dstAccessMask = vk::AccessFlagBits::eShaderRead,
-        .buffer = emitter.particleData->GetVkBuffer(),
-        .offset = emitter.dynamicOffsets[frameIndex][DYOFF_INDEX_PARTICLE_INPUT],
-        .size = emitter.chunkSize
-      };
-
-      // ...copy assign barrier on heap 
-      preUpdateBarriers[i] = barrier;
+      // prepare barriers
+      PreparePrePostUpdateBarriers(preUpdateBarriers, postUpdateBarriers, emitter, i, frameIndex);
 
+      // Emitter will emit once and stop emitting next frame (unless specified before reaching here to do so).
       emitter.toEmit = false;
       ++i;
     }
@@ -275,6 +328,8 @@ namespace SHADE
     // issue the barrier to wait
     cmdBuffer->PipelineBarrier(vk::PipelineStageFlagBits::eComputeShader, vk::PipelineStageFlagBits::eComputeShader, {}, {}, preUpdateBarriers, {});
 
+
+
     /*-----------------------------------------------------------------------*/
     /* EMITTING PARTICLES DONE, BEGIN UPDATES....                            */
     /*-----------------------------------------------------------------------*/
@@ -287,6 +342,11 @@ namespace SHADE
       UpdateCompoennt(cmdBuffer, emitter, frameIndex);
     }
 
+    /*-----------------------------------------------------------------------*/
+    /* AFTER UPDATING, RENDER PARTICLES                                      */
+    /*-----------------------------------------------------------------------*/
+    // issue the barrier to wait for output particles to be done updating and indices data to finish being modified.
+    cmdBuffer->PipelineBarrier(vk::PipelineStageFlagBits::eComputeShader, vk::PipelineStageFlagBits::eComputeShader, {}, {}, postUpdateBarriers, {});
 
   }
 
@@ -297,7 +357,7 @@ namespace SHADE
     // TODO: Issue barrier for output particle data. Semaphore should also be issued outside in SHGraphicsSystem
     for (auto& emitter : emitters)
     {
-    	
+    	RenderComponent(cmdBuffer, emitter, frameIndex);
     }
   }
 

SHADE_Engine/src/Graphics/MiddleEnd/Particles/SHParticleSubSystem.h

@@ -81,6 +81,8 @@ namespace SHADE
     void UpdateCompoennt(Handle<SHVkCommandBuffer> cmdBuffer, SHParticleEmitterComponent& comp, uint32_t frameIndex) noexcept;
     void RenderComponent(Handle<SHVkCommandBuffer> cmdBuffer, SHParticleEmitterComponent& comp, uint32_t frameIndex) noexcept;
 
+    void PreparePrePostUpdateBarriers (std::vector<vk::BufferMemoryBarrier>& preUpdateBarriers, std::vector<vk::BufferMemoryBarrier>& postUpdateBarriers, SHParticleEmitterComponent const& emitter, uint32_t const EMITTER_INDEX, uint32_t const FRAME_INDEX) noexcept;
+
   public:
     void Init(Handle<SHVkLogicalDevice> device, Handle<SHVkDescriptorPool> inDescPool, Handle<SHVkRenderpass> compatibleRenderpass, Handle<SHSubpass> subpass, Handle<SHVkShaderModule> VS, Handle<SHVkShaderModule> FS, Handle<SHVkShaderModule> emitCS, Handle<SHVkShaderModule> defaultUpdateCS) noexcept;
 

SHADE_Engine/src/Graphics/MiddleEnd/TrajectoryRendering/SHTrajectoryRenderingSubSystem.cpp

@@ -198,7 +198,7 @@ namespace SHADE
       cmdBuffer->BindVertexBuffer(SHGraphicsConstants::VertexBufferBindings::TRAJECTORY_TRANSFORM, transformBuffer, 0);
 
       // call draw call
-      cmdBuffer->DrawMultiIndirect(drawDataBuffer, drawData.size());
+      cmdBuffer->DrawMultiIndirectIndexed(drawDataBuffer, drawData.size());
 
       // clear CPU transform and draw data
       transformData.clear();