I’m building a video game engine using C++ as the coding language and Vulkan for graphics. I am trying to set up a generic renderer using Vulkan that is flexible and will render objects based on a vector that is supplied to it. The renderer will also handle the creation of the window using GLFW and use GLM for all relevant math calls. I am using the ASSIMP library to load 3d models and animations.

Here is a portion of the code:

Renderer.h:

#pragma once

#include <vulkan/vulkan.h>
#include "Window.h"
#include <vector>
#include <stdexcept>
#include <set>
#include <optional>
#include <iostream>
#include "Pipeline.h"
#include "Material.h"
#include "Mesh.h"

struct QueueFamilyIndices
{
	std::optional<uint32_t> graphicsFamily;
	std::optional<uint32_t> presentFamily;

	bool IsComplete()
	{
		return graphicsFamily.has_value() && presentFamily.has_value();
	}
};

struct SwapChainSupportDetails {
	VkSurfaceCapabilitiesKHR capabilities;
	std::vector<VkSurfaceFormatKHR> formats;
	std::vector<VkPresentModeKHR> presentModes;
};



class Renderer
{
public:
	Renderer();
	~Renderer();

	void Initialize(GLFWwindow* window);
	void Shutdown();

	void BeginFrame();
	void EndFrame();

	VkDescriptorSetLayout CreateDescriptorSetLayout();
	VkDescriptorPool CreateDescriptorPool(uint32_t maxSets);
	VkDevice* GetDevice();
	VkPhysicalDevice* GetPhysicalDevice();
	VkCommandPool* GetCommandPool();
	VkQueue* GetGraphicsQueue();
	VkCommandBuffer* GetCurrentCommandBuffer();
	std::shared_ptr<Pipeline> GetPipeline();
	void CreateGraphicsPipeline(Mesh* mesh, Material* material);
	VkDescriptorSetLayout CreateSamplerDescriptorSetLayout();

private:
	bool shutdownInProgress;
	uint32_t currentCmdBufferIndex = 0;
	std::vector<size_t> currentFramePerImage;

	std::vector<VkImage> swapChainImages;
	std::vector<VkImageView> swapChainImageViews;
	VkExtent2D swapChainExtent;
	VkRenderPass renderPass;
	uint32_t imageIndex;
	std::shared_ptr<Pipeline> pipeline;

	VkFormat swapChainImageFormat;

	std::vector<VkCommandBuffer> commandBuffers;

	void CreateImageViews();
	void CleanupImageViews();
	void CreateRenderPass();
	void CleanupRenderPass();

	void CreateSurface();
	void DestroySurface();

	void CreateInstance();
	void CleanupInstance();
	void ChoosePhysicalDevice();
	void CreateDevice();
	void CleanupDevice();
	void CreateSwapchain();
	void CleanupSwapchain();
	void CreateCommandPool();
	void CleanupCommandPool();
	void CreateFramebuffers();
	void CleanupFramebuffers();

	void CreateCommandBuffers();
	void CleanupCommandBuffers();

	void Present();

	

	

	GLFWwindow* window;
	VkInstance instance = VK_NULL_HANDLE;
	VkPhysicalDevice physicalDevice = VK_NULL_HANDLE;
	VkDevice device = VK_NULL_HANDLE;

	VkSurfaceKHR surface;
	VkSwapchainKHR swapchain;
	VkCommandPool commandPool;
	VkCommandBuffer currentCommandBuffer;

	std::vector<VkFramebuffer> framebuffers;

	// Additional Vulkan objects needed for rendering…

	const uint32_t kMaxFramesInFlight = 2;
	std::vector<VkSemaphore> imageAvailableSemaphores;
	std::vector<VkSemaphore> renderFinishedSemaphores;
	std::vector<VkFence> inFlightFences;
	size_t currentFrame;

	VkQueue graphicsQueue;
	VkQueue presentQueue;

	void CreateSyncObjects();
	void CleanupSyncObjects();

	SwapChainSupportDetails querySwapChainSupport(VkPhysicalDevice device, VkSurfaceKHR surface);
	VkSurfaceFormatKHR chooseSwapSurfaceFormat(const std::vector<VkSurfaceFormatKHR>& availableFormats);
	VkPresentModeKHR chooseSwapPresentMode(const std::vector<VkPresentModeKHR>& availablePresentModes);
	VkExtent2D chooseSwapExtent(const VkSurfaceCapabilitiesKHR& capabilities, GLFWwindow* window);

	std::vector<const char*> deviceExtensions = {
		VK_KHR_SWAPCHAIN_EXTENSION_NAME
	};

	std::vector<const char*> CheckPhysicalDeviceExtensionSupport(VkPhysicalDevice physicalDevice);
	QueueFamilyIndices GetQueueFamilyIndices(VkPhysicalDevice physicalDevice);
};

GameObject.h:

#pragma once

#include <glm/glm.hpp>
#include "Mesh.h"
#include "Material.h"
#include "Camera.h"
#include "Renderer.h"

class GameObject
{
public:
	GameObject();
	~GameObject();

	void Initialize();
	void Update(float deltaTime);
	void Render(Renderer& renderer, const Camera& camera);
	void Shutdown();

	void SetPosition(const glm::vec3& position);
	void SetRotation(const glm::vec3& rotation);
	void SetScale(const glm::vec3& scale);

	Mesh* GetMesh();
	Material* GetMaterial();

private:
	glm::mat4 modelMatrix;
	glm::vec3 position;
	glm::vec3 rotation;
	glm::vec3 scale;

	Mesh* mesh;
	Material* material;

	bool initialized = false;

	void UpdateModelMatrix();
};

GameObject.cpp:

#include "GameObject.h"
#include <glm/gtc/matrix_transform.hpp>

GameObject::GameObject()
	: position(0.0f), rotation(0.0f), scale(1.0f)
{
}

GameObject::~GameObject()
{
    if (initialized)
    {
        Shutdown();
    }
}

void GameObject::Initialize()
{
    mesh = new Mesh{};
    material = new Material{};
    this->initialized = true;
}

void GameObject::Update(float deltaTime)
{
	// Update position, rotation, scale, and other properties
	// Example: Rotate the object around the Y-axis
	rotation.y += deltaTime * glm::radians(90.0f);
	UpdateModelMatrix();
}

void GameObject::Render(Renderer& renderer, const Camera& camera)
{
    // Render this object using the renderer and camera
    VkDevice device = *renderer.GetDevice();

    // Bind mesh vertex and index buffers
    VkBuffer vertexBuffers[] = { mesh->GetVertexBuffer() };
    VkDeviceSize offsets[] = { 0 };
    vkCmdBindVertexBuffers(*renderer.GetCurrentCommandBuffer(), 0, 1, vertexBuffers, offsets);
    vkCmdBindIndexBuffer(*renderer.GetCurrentCommandBuffer(), mesh->GetIndexBuffer(), 0, VK_INDEX_TYPE_UINT32);

    // Update shader uniform buffers with modelMatrix, viewMatrix and projectionMatrix transforms
    struct MVP {
        glm::mat4 model;
        glm::mat4 view;
        glm::mat4 projection;
    } mvp;

    mvp.model = modelMatrix;
    mvp.view = camera.GetViewMatrix();
    mvp.projection = camera.GetProjectionMatrix();

    // Create a new buffer to hold the MVP data temporarily
    VkBuffer mvpBuffer;
    VkDeviceMemory mvpBufferMemory;
    BufferUtils::CreateBuffer(device, *renderer.GetPhysicalDevice(),
        sizeof(MVP), VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT,
        VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT,
        mvpBuffer, mvpBufferMemory);

    material->CreateDescriptorSet(renderer.CreateDescriptorSetLayout(), renderer.CreateDescriptorPool(1), mvpBuffer, sizeof(MVP));
    // Map the MVP data into the buffer and unmap
    void* data = nullptr;
    vkMapMemory(device, mvpBufferMemory, 0, sizeof(MVP), 0, &data);
    memcpy(data, &mvp, sizeof(MVP));
    vkUnmapMemory(device, mvpBufferMemory);

    // TODO: Modify your material, descriptor set, and pipeline to use this new mvpBuffer instead of
    // the default uniform buffer



    // Bind the DescriptorSet associated with the material
    VkDescriptorSet descriptorSet = material->GetDescriptorSet();
    material->UpdateBufferBinding(descriptorSet, mvpBuffer, device, sizeof(MVP));
    renderer.CreateGraphicsPipeline(mesh, material);
    vkCmdBindPipeline(*renderer.GetCurrentCommandBuffer(), VK_PIPELINE_BIND_POINT_GRAPHICS, renderer.GetPipeline().get()->GetPipeline());
    vkCmdBindDescriptorSets(*renderer.GetCurrentCommandBuffer(), VK_PIPELINE_BIND_POINT_GRAPHICS, material->GetPipelineLayout(), 0, 1, &descriptorSet, 0, nullptr);

    // Call vkCmdDrawIndexed()
    uint32_t numIndices = static_cast<uint32_t>(mesh->GetIndices().size());
    vkCmdDrawIndexed(*renderer.GetCurrentCommandBuffer(), numIndices, 1, 0, 0, 0);

    // Cleanup the temporary buffer
    //vkDestroyBuffer(device, mvpBuffer, nullptr);
    //vkFreeMemory(device, mvpBufferMemory, nullptr);
}

void GameObject::Shutdown()
{
	// Clean up resources, if necessary
	// (depending on how Mesh and Material resources are managed)
    delete mesh;
    delete material;
    this->initialized = false;
}

void GameObject::SetPosition(const glm::vec3& position)
{
	this->position = position;
	UpdateModelMatrix();
}

void GameObject::SetRotation(const glm::vec3& rotation)
{
	this->rotation = rotation;
	UpdateModelMatrix();
}

void GameObject::SetScale(const glm::vec3& scale)
{
	this->scale = scale;
	UpdateModelMatrix();
}

void GameObject::UpdateModelMatrix()
{
	modelMatrix = glm::mat4(1.0f);
	modelMatrix = glm::translate(modelMatrix, position);
	modelMatrix = glm::rotate(modelMatrix, rotation.x, glm::vec3(1.0f, 0.0f, 0.0f));
	modelMatrix = glm::rotate(modelMatrix, rotation.y, glm::vec3(0.0f, 1.0f, 0.0f));
	modelMatrix = glm::rotate(modelMatrix, rotation.z, glm::vec3(0.0f, 0.0f, 1.0f));
	modelMatrix = glm::scale(modelMatrix, scale);
}

Mesh* GameObject::GetMesh()
{
    return mesh;
}
Material* GameObject::GetMaterial()
{
    return material;
}

Engine.h:

#pragma once

#include "Window.h"
#include "Renderer.h"
#include "Scene.h"
#include <chrono>
#include <thread>

class Engine
{
public:
	Engine();
	~Engine();

	void Run();
	void Shutdown();

	int MaxFPS = 60;

private:

	void Initialize();
	void MainLoop();
	void Update(float deltaTime);
	void Render();

	Window window;
	Renderer renderer;
	Scene scene;
};

Scene.h:

#pragma once

#include <vector>
#include "GameObject.h"
#include "Camera.h"
#include "Renderer.h"

class Scene
{
public:
	Scene();
	~Scene();

	void Initialize();
	void Update(float deltaTime);
	void Render(Renderer& renderer);
	void Shutdown();

	void AddGameObject(GameObject* gameObject);
	Camera& GetCamera();
	float temp;

private:
	std::vector<GameObject*> gameObjects;
	Camera camera;
};

BufferUtils.h:

#pragma once

#include <vulkan/vulkan.h>
#include <stdint.h>

namespace BufferUtils
{
    void CreateBuffer(
        VkDevice device, VkPhysicalDevice physicalDevice,
        VkDeviceSize size, VkBufferUsageFlags usage, VkMemoryPropertyFlags properties,
        VkBuffer& buffer, VkDeviceMemory& bufferMemory);

    uint32_t FindMemoryType(VkPhysicalDevice physicalDevice, uint32_t typeFilter, VkMemoryPropertyFlags properties);

    void CopyBuffer(
        VkDevice device, VkCommandPool commandPool, VkQueue graphicsQueue,
        VkBuffer srcBuffer, VkBuffer dstBuffer, VkDeviceSize size);
}


BufferUtils.cpp:

#include "BufferUtils.h"

#include <stdexcept>

namespace BufferUtils
{
    void CreateBuffer(
        VkDevice device, VkPhysicalDevice physicalDevice,
        VkDeviceSize size, VkBufferUsageFlags usage, VkMemoryPropertyFlags properties,
        VkBuffer& buffer, VkDeviceMemory& bufferMemory)
    {
        VkBufferCreateInfo bufferInfo{};
        bufferInfo.sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO;
        bufferInfo.size = size;
        bufferInfo.usage = usage;
        bufferInfo.sharingMode = VK_SHARING_MODE_EXCLUSIVE;

        if (vkCreateBuffer(device, &bufferInfo, nullptr, &buffer) != VK_SUCCESS)
        {
            throw std::runtime_error("Failed to create buffer!");
        }

        VkMemoryRequirements memRequirements;
        vkGetBufferMemoryRequirements(device, buffer, &memRequirements);

        VkMemoryAllocateInfo allocInfo{};
        allocInfo.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
        allocInfo.allocationSize = memRequirements.size;
        allocInfo.memoryTypeIndex = FindMemoryType(physicalDevice, memRequirements.memoryTypeBits, properties);

        if (vkAllocateMemory(device, &allocInfo, nullptr, &bufferMemory) != VK_SUCCESS)
        {
            throw std::runtime_error("Failed to allocate buffer memory!");
        }

        vkBindBufferMemory(device, buffer, bufferMemory, 0);
    }

    uint32_t FindMemoryType(VkPhysicalDevice physicalDevice, uint32_t typeFilter, VkMemoryPropertyFlags properties)
    {
        VkPhysicalDeviceMemoryProperties memProperties;
        vkGetPhysicalDeviceMemoryProperties(physicalDevice, &memProperties);

        for (uint32_t i = 0; i < memProperties.memoryTypeCount; i++)
        {
            if ((typeFilter & (1 << i)) && (memProperties.memoryTypes[i].propertyFlags & properties) == properties)
            {
                return i;
            }
        }

        throw std::runtime_error("Failed to find suitable memory type!");
    }

    void CopyBuffer(
        VkDevice device, VkCommandPool commandPool, VkQueue graphicsQueue,
        VkBuffer srcBuffer, VkBuffer dstBuffer, VkDeviceSize size)
    {
        VkCommandBufferAllocateInfo allocInfo{};
        allocInfo.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO;
        allocInfo.level = VK_COMMAND_BUFFER_LEVEL_PRIMARY;
        allocInfo.commandPool = commandPool;
        allocInfo.commandBufferCount = 1;

        VkCommandBuffer commandBuffer;
        vkAllocateCommandBuffers(device, &allocInfo, &commandBuffer);

        VkCommandBufferBeginInfo beginInfo{};
        beginInfo.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
        beginInfo.flags = VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT;

        vkBeginCommandBuffer(commandBuffer, &beginInfo);

        VkBufferCopy copyRegion{};
        copyRegion.srcOffset = 0; // Optional
        copyRegion.dstOffset = 0; // Optional
        copyRegion.size = size;
        vkCmdCopyBuffer(commandBuffer, srcBuffer, dstBuffer, 1, &copyRegion);

        vkEndCommandBuffer(commandBuffer);

        VkSubmitInfo submitInfo{};
        submitInfo.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
        submitInfo.commandBufferCount = 1;
        submitInfo.pCommandBuffers = &commandBuffer;

        vkQueueSubmit(graphicsQueue, 1, &submitInfo, VK_NULL_HANDLE);
        vkQueueWaitIdle(graphicsQueue);

        vkFreeCommandBuffers(device, commandPool, 1, &commandBuffer);
    }
}

Camera.h:

#pragma once

#include <glm/glm.hpp>

class Camera
{
public:
	Camera();
	~Camera();

	void Initialize(float aspectRatio);
	void Shutdown();

	void SetPosition(const glm::vec3& position);
	void SetRotation(const glm::vec3& rotation);

	const glm::mat4& GetViewMatrix() const;
	const glm::mat4& GetProjectionMatrix() const;

private:
	glm::vec3 position;
	glm::vec3 rotation;
	glm::mat4 viewMatrix;
	glm::mat4 projectionMatrix;

	void UpdateViewMatrix();
};

Camera.cpp:

#include "Camera.h"
#include <glm/gtc/matrix_transform.hpp>

Camera::Camera()
	: position(0.0f), rotation(0.0f)
{
}

Camera::~Camera()
{
	Shutdown();
}

void Camera::Initialize(float aspectRatio)
{
	projectionMatrix = glm::perspective(glm::radians(45.0f), aspectRatio, 0.1f, 100.0f);
}

void Camera::Shutdown()
{
}

void Camera::SetPosition(const glm::vec3& position)
{
	this->position = position;
	UpdateViewMatrix();
}

void Camera::SetRotation(const glm::vec3& rotation)
{
	this->rotation = rotation;
	UpdateViewMatrix();
}

const glm::mat4& Camera::GetViewMatrix() const
{
	return viewMatrix;
}

const glm::mat4& Camera::GetProjectionMatrix() const
{
	return projectionMatrix;
}

void Camera::UpdateViewMatrix()
{
	glm::mat4 rotMatrix = glm::mat4(1.0f);
	rotMatrix = glm::rotate(rotMatrix, rotation.x, glm::vec3(1.0f, 0.0f, 0.0f));
	rotMatrix = glm::rotate(rotMatrix, rotation.y, glm::vec3(0.0f, 1.0f, 0.0f));
	rotMatrix = glm::rotate(rotMatrix, rotation.z, glm::vec3(0.0f, 0.0f, 1.0f));

	glm::vec3 lookAt = glm::vec3(rotMatrix * glm::vec4(0.0f, 0.0f, -1.0f, 0.0f));

	viewMatrix = glm::lookAt(position, position + lookAt, glm::vec3(0.0f, 1.0f, 0.0f));
}

Here are some relevant methods from Renderer.cpp:

VkDescriptorSetLayout Renderer::CreateDescriptorSetLayout() {
	VkDescriptorSetLayoutBinding uboLayoutBinding{};
	uboLayoutBinding.binding = 0;
	uboLayoutBinding.descriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
	uboLayoutBinding.descriptorCount = 1;
	uboLayoutBinding.stageFlags = VK_SHADER_STAGE_VERTEX_BIT;
	uboLayoutBinding.pImmutableSamplers = nullptr;

	// Add sampler layout binding
	VkDescriptorSetLayoutBinding samplerLayoutBinding{};
	samplerLayoutBinding.binding = 1;
	samplerLayoutBinding.descriptorType = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
	samplerLayoutBinding.descriptorCount = 1;
	samplerLayoutBinding.stageFlags = VK_SHADER_STAGE_FRAGMENT_BIT;
	samplerLayoutBinding.pImmutableSamplers = nullptr;

	std::array<VkDescriptorSetLayoutBinding, 2> bindings = { uboLayoutBinding, samplerLayoutBinding };

	VkDescriptorSetLayoutCreateInfo layoutInfo{};
	layoutInfo.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO;
	layoutInfo.bindingCount = static_cast<uint32_t>(bindings.size());
	layoutInfo.pBindings = bindings.data();

	VkDescriptorSetLayout descriptorSetLayout;
	if (vkCreateDescriptorSetLayout(device, &layoutInfo, nullptr, &descriptorSetLayout) != VK_SUCCESS) {
		throw std::runtime_error("Failed to create descriptor set layout!");
	}

	return descriptorSetLayout;
}

VkDescriptorSetLayout Renderer::CreateSamplerDescriptorSetLayout() {
	VkDescriptorSetLayoutBinding samplerLayoutBinding{};
	samplerLayoutBinding.binding = 0;
	samplerLayoutBinding.descriptorType = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
	samplerLayoutBinding.descriptorCount = 1;
	samplerLayoutBinding.stageFlags = VK_SHADER_STAGE_FRAGMENT_BIT;
	samplerLayoutBinding.pImmutableSamplers = nullptr;

	VkDescriptorSetLayoutCreateInfo layoutInfo{};
	layoutInfo.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO;
	layoutInfo.bindingCount = 1;
	layoutInfo.pBindings = &samplerLayoutBinding;

	VkDescriptorSetLayout descriptorSetLayout;
	if (vkCreateDescriptorSetLayout(device, &layoutInfo, nullptr, &descriptorSetLayout) != VK_SUCCESS) {
		throw std::runtime_error("Failed to create sampler descriptor set layout!");
	}

	return descriptorSetLayout;
}

VkDescriptorPool Renderer::CreateDescriptorPool(uint32_t maxSets) {
	VkDescriptorPoolSize poolSize{};
	poolSize.type = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
	poolSize.descriptorCount = maxSets;

	// Add an additional descriptor pool size for COMBINED_IMAGE_SAMPLER
	VkDescriptorPoolSize samplerPoolSize{};
	samplerPoolSize.type = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
	samplerPoolSize.descriptorCount = maxSets;

	std::array<VkDescriptorPoolSize, 2> poolSizes = { poolSize, samplerPoolSize };

	VkDescriptorPoolCreateInfo poolInfo{};
	poolInfo.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO;
	poolInfo.poolSizeCount = static_cast<uint32_t>(poolSizes.size());
	poolInfo.pPoolSizes = poolSizes.data();
	poolInfo.maxSets = maxSets;

	VkDescriptorPool descriptorPool;
	if (vkCreateDescriptorPool(device, &poolInfo, nullptr, &descriptorPool) != VK_SUCCESS) {
		throw std::runtime_error("Failed to create descriptor pool!");
	}

	return descriptorPool;
}

Vertex Shader:

#version 450

layout(binding = 0) uniform UniformBufferObject {
    mat4 model;
    mat4 view;
    mat4 proj;
} ubo;

layout(location = 0) in vec3 inPosition;
layout(location = 1) in vec3 inColor;

layout(location = 0) out vec3 fragColor;


void main() {
    gl_Position = ubo.proj * ubo.view * ubo.model * vec4(inPosition, 1.0);
    fragColor = inColor;
}

Fragment Shader:

#version 450

layout(binding = 1) uniform sampler2D texSampler;

layout(location = 0) in vec3 fragColor;

layout(location = 0) out vec4 outColor;

void main() {
    outColor = vec4(1,0,1,1);
}

The code currently creates a square tile somewhere in the scene. I'm concerned it may not be rendering at all. How can I adjust the code so it is pointing at the tile so I can verify it is rendering properly?