Vulkan Mesh Shader Notes

Quick Start

• Check for support

      VkPhysicalDeviceMeshShaderFeaturesNV meshShader = {};
      meshShader.sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_MESH_SHADER_FEATURES_NV;
  
      VkPhysicalDeviceFeatures2 features2 = {};
      features2.sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_FEATURES_2_KHR;
      features2.pNext = &meshShader;
  
      vkGetPhysicalDeviceFeatures2(gpu, &features2);
      if (meshShader.meshShader && meshShader.taskShader) {
          exit(-1);
      }
                  

• Enable device extension

      vector extensions({ VK_KHR_SWAPCHAIN_EXTENSION_NAME });
  
      if (vk.supportsMeshShaders) {
          extensions.push_back(VK_NV_MESH_SHADER_EXTENSION_NAME);
      }
                  

• Enable device features

      VkPhysicalDeviceMeshShaderFeaturesNV meshFeatures = {};
      meshFeatures.sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_MESH_SHADER_FEATURES_NV;
      meshFeatures.meshShader = true;
      meshFeatures.taskShader = true;
  
      VkPhysicalDeviceFeatures2 features = {};
      features.sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_FEATURES_2_KHR;
  
      if (vk.supportsMeshShaders) {
          features.pNext = &meshFeatures;
      }
  
      VkDeviceCreateInfo createInfo = {};
      createInfo.sType = VK_STRUCTURE_TYPE_DEVICE_CREATE_INFO;
      createInfo.pNext = &features;
      createInfo.queueCreateInfoCount = static_cast<uint32_t>(
          queueCreateInfos.size()
      );
      createInfo.pQueueCreateInfos = queueCreateInfos.data();
      createInfo.enabledExtensionCount = (uint32_t)extensions.size();
      createInfo.ppEnabledExtensionNames = extensions.data();
  
      checkSuccess(vkCreateDevice(vk.gpu, &createInfo, nullptr, &vk.device));
                  

• Get function pointer

      PFN_vkVoidFunction getFunction(Vulkan& vk, const char* name) {
          auto result = vkGetDeviceProcAddr(vk.device, name);
          if (result == NULL) {
              LOG(ERROR) << "could not find " << name;
              exit(-1);
          }
          return result;
      }
  
      void getFunctions(Vulkan& vk) {
          vk.cmdDrawMeshTasksNV =
              (PFN_vkCmdDrawMeshTasksNV)
              getFunction(vk, "vkCmdDrawMeshTasksNV");
      }
                  

• Fill out empty vertex input stage for pipeline

      VkPipelineVertexInputStateCreateInfo vertexInput = {};