CreateTopLevelAS()

void Spices::RayTracingRenderer::CreateTopLevelAS ( FrameInfo & frameInfo, std::shared_ptr< std::vector< uint32_t > > view, std::shared_ptr< VulkanRayTracing > rayTracingInstance, bool update = false )

private

Create TopLevelAS.

Parameters

[in]	frameInfo	FrameInfo.
[in]	view	Component View.
[in]	rayTracingInstance	VulkanRayTracingInstance.
[in]	update	default false.

Cache this frame hit groups.

Build TLAS.

Cache this frame hit groups.

Build TLAS.

Definition at line 247 of file RayTracingRenderer.cpp.

    {
        SPICES_PROFILE_ZONE;
 
        std::vector<VkAccelerationStructureInstanceKHR> tlas;
        std::shared_ptr<std::unordered_map<std::string, uint32_t>> hitGroups = std::make_shared<std::unordered_map<std::string, uint32_t>>();
 
        int index = 0;
        auto& desc = rayTracingInstance->GetMeshDesc().attributes;
        desc->resize(SpicesShader::MESH_BUFFER_MAXNUM, 0);
 
        frameInfo.m_World->ViewComponent<MeshComponent>(*view, [&](auto e, auto& meshComp){
            
            auto& tranComp = frameInfo.m_World->GetComponent<TransformComponent>(static_cast<entt::entity>(e));
 
            meshComp.GetMesh()->AddMaterialToHitGroup(*hitGroups);
            meshComp.GetMesh()->GetPacks().for_each([&](const uint32_t& k, const std::shared_ptr<MeshPack>& v) {
 
                VkAccelerationStructureInstanceKHR                            rayInst{};
                rayInst.transform                                           = ToVkTransformMatrixKHR(tranComp.GetModelMatrix());          // Position of the instance
                rayInst.instanceCustomIndex                                 = index;                                                      // gl_InstanceCustomIndexEXT
                rayInst.accelerationStructureReference                      = v->GetAccel().accel->GetACDeviceAddress();
                rayInst.flags                                               = VK_GEOMETRY_INSTANCE_TRIANGLE_FACING_CULL_DISABLE_BIT_KHR;
                rayInst.mask                                                = 0xFF;                                                       // Only be hit if rayMask & instance.mask != 0
                rayInst.instanceShaderBindingTableRecordOffset              = v->GetHitShaderHandle();                                    // We will use the same hit group for all objects
 
                tlas.push_back(rayInst);
 
                (*desc)[index] = v->GetMeshDesc().GetBufferAddress();
 
                index += 1;
                return false;
            });
 
            return false;
        });
 
        rayTracingInstance->GetMeshDesc().CreateBuffer("MeshDescBuffer", VK_BUFFER_USAGE_STORAGE_BUFFER_BIT);
 
        SetHitGroupsCache(hitGroups);
 
        rayTracingInstance->SetHitGroups(hitGroups);
 
        rayTracingInstance->BuildTLAS(
            tlas,
            VK_BUILD_ACCELERATION_STRUCTURE_PREFER_FAST_TRACE_BIT_KHR |
            VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_UPDATE_BIT_KHR      |
            VK_BUILD_ACCELERATION_STRUCTURE_ALLOW_COMPACTION_BIT_KHR  ,
            update
        );
    }