Started working on sample showing comparing separate/interleaved vertex attributes

base/VulkanUIOverlay.cpp

@@ -434,6 +434,13 @@ namespace vks
 		return res;
 	}
 
+	bool UIOverlay::radioButton(const char* caption, bool value)
+	{
+		bool res = ImGui::RadioButton(caption, value);
+		if (res) { updated = true; };
+		return res;
+	}
+
 	bool UIOverlay::inputFloat(const char *caption, float *value, float step, uint32_t precision)
 	{
 		bool res = ImGui::InputFloat(caption, value, step, step * 10.0f, precision);

base/VulkanUIOverlay.h

@@ -81,6 +81,7 @@ namespace vks
 		bool header(const char* caption);
 		bool checkBox(const char* caption, bool* value);
 		bool checkBox(const char* caption, int32_t* value);
+		bool radioButton(const char* caption, bool value);
 		bool inputFloat(const char* caption, float* value, float step, uint32_t precision);
 		bool sliderFloat(const char* caption, float* value, float min, float max);
 		bool sliderInt(const char* caption, int32_t* value, int32_t min, int32_t max);

data/shaders/glsl/vertexattributes/scene.frag

@@ -0,0 +1,43 @@
+#version 450
+
+layout (set = 1, binding = 0) uniform sampler2D samplerColorMap;
+layout (set = 1, binding = 1) uniform sampler2D samplerNormalMap;
+
+layout (location = 0) in vec3 inNormal;
+layout (location = 1) in vec2 inUV;
+layout (location = 2) in vec3 inViewVec;
+layout (location = 3) in vec3 inLightVec;
+layout (location = 4) in vec4 inTangent;
+
+layout (location = 0) out vec4 outFragColor;
+
+layout(push_constant) uniform PushConsts {
+	mat4 model;
+	uint alphaMask;
+	float alphaMaskCuttoff;
+} pushConsts;
+
+void main() 
+{
+	vec4 color = texture(samplerColorMap, inUV);
+
+	if (pushConsts.alphaMask == 1) {
+		if (color.a < pushConsts.alphaMaskCuttoff) {
+			discard;
+		}
+	}
+
+	vec3 N = normalize(inNormal);
+	vec3 T = normalize(inTangent.xyz);
+	vec3 B = cross(inNormal, inTangent.xyz) * inTangent.w;
+	mat3 TBN = mat3(T, B, N);
+	N = TBN * normalize(texture(samplerNormalMap, inUV).xyz * 2.0 - vec3(1.0));
+
+	const float ambient = 0.1;
+	vec3 L = normalize(inLightVec);
+	vec3 V = normalize(inViewVec);
+	vec3 R = reflect(-L, N);
+	vec3 diffuse = max(dot(N, L), ambient).rrr;
+	float specular = pow(max(dot(R, V), 0.0), 32.0);
+	outFragColor = vec4(diffuse * color.rgb + specular, color.a);
+}

data/shaders/glsl/vertexattributes/scene.vert

@@ -0,0 +1,39 @@
+#version 450
+
+layout (location = 0) in vec3 inPos;
+layout (location = 1) in vec3 inNormal;
+layout (location = 2) in vec2 inUV;
+layout (location = 3) in vec4 inTangent;
+
+layout (set = 0, binding = 0) uniform UBOScene 
+{
+	mat4 projection;
+	mat4 view;
+	vec4 lightPos;
+	vec4 viewPos;
+} uboScene;
+
+layout(push_constant) uniform PushConsts {
+	mat4 model;
+	uint alphaMask;
+	float alphaMaskCuttoff;
+} pushConsts;
+
+layout (location = 0) out vec3 outNormal;
+layout (location = 1) out vec2 outUV;
+layout (location = 2) out vec3 outViewVec;
+layout (location = 3) out vec3 outLightVec;
+layout (location = 4) out vec4 outTangent;
+
+void main() 
+{
+	outNormal = inNormal;
+	outUV = inUV;
+	outTangent = inTangent;
+	gl_Position = uboScene.projection * uboScene.view * pushConsts.model * vec4(inPos.xyz, 1.0);
+	
+	outNormal = mat3(pushConsts.model) * inNormal;
+	vec4 pos = pushConsts.model * vec4(inPos, 1.0);
+	outLightVec = uboScene.lightPos.xyz - pos.xyz;
+	outViewVec = uboScene.viewPos.xyz - pos.xyz;
+}

examples/CMakeLists.txt

@@ -136,6 +136,7 @@ set(EXAMPLES
 	texturesparseresidency
 	triangle
 	variablerateshading
+	vertexattributes
 	viewportarray
 	vulkanscene
 )

examples/vertexattributes/README.md

@@ -0,0 +1,5 @@
+# Vertex attributes
+
+## Synopsis
+
+This sample demonstrates how to pass vertex attributes using interleaved or separate buffers.

examples/vertexattributes/vertexattributes.cpp

@@ -0,0 +1,657 @@
+/*
+ * Vulkan Example - Passing vertex attributes using interleaved and separate buffers
+ *
+ * Copyright (C) 2021 by Sascha Willems - www.saschawillems.de
+ *
+ * This code is licensed under the MIT license (MIT) (http://opensource.org/licenses/MIT)
+ */
+
+#include "vertexattributes.h"
+
+/*
+	Vulkan glTF scene class
+*/
+
+VulkanglTFScene::~VulkanglTFScene()
+{
+	// Release all Vulkan resources allocated for the model
+	vertices.destroy();
+	indices.destroy();
+	for (Image image : images) {
+		vkDestroyImageView(vulkanDevice->logicalDevice, image.texture.view, nullptr);
+		vkDestroyImage(vulkanDevice->logicalDevice, image.texture.image, nullptr);
+		vkDestroySampler(vulkanDevice->logicalDevice, image.texture.sampler, nullptr);
+		vkFreeMemory(vulkanDevice->logicalDevice, image.texture.deviceMemory, nullptr);
+	}
+}
+
+/*
+	glTF loading functions
+
+	The following functions take a glTF input model loaded via tinyglTF and convert all required data into our own structure
+*/
+
+void VulkanglTFScene::loadImages(tinygltf::Model& input)
+{
+	// POI: The textures for the glTF file used in this sample are stored as external ktx files, so we can directly load them from disk without the need for conversion
+	images.resize(input.images.size());
+	for (size_t i = 0; i < input.images.size(); i++) {
+		tinygltf::Image& glTFImage = input.images[i];
+		images[i].texture.loadFromFile(path + "/" + glTFImage.uri, VK_FORMAT_R8G8B8A8_UNORM, vulkanDevice, copyQueue);
+	}
+}
+
+void VulkanglTFScene::loadTextures(tinygltf::Model& input)
+{
+	textures.resize(input.textures.size());
+	for (size_t i = 0; i < input.textures.size(); i++) {
+		textures[i].imageIndex = input.textures[i].source;
+	}
+}
+
+void VulkanglTFScene::loadMaterials(tinygltf::Model& input)
+{
+	materials.resize(input.materials.size());
+	for (size_t i = 0; i < input.materials.size(); i++) {
+		// We only read the most basic properties required for our sample
+		tinygltf::Material glTFMaterial = input.materials[i];
+		// Get the base color factor
+		if (glTFMaterial.values.find("baseColorFactor") != glTFMaterial.values.end()) {
+			materials[i].baseColorFactor = glm::make_vec4(glTFMaterial.values["baseColorFactor"].ColorFactor().data());
+		}
+		// Get base color texture index
+		if (glTFMaterial.values.find("baseColorTexture") != glTFMaterial.values.end()) {
+			materials[i].baseColorTextureIndex = glTFMaterial.values["baseColorTexture"].TextureIndex();
+		}
+		// Get the normal map texture index
+		if (glTFMaterial.additionalValues.find("normalTexture") != glTFMaterial.additionalValues.end()) {
+			materials[i].normalTextureIndex = glTFMaterial.additionalValues["normalTexture"].TextureIndex();
+		}
+		// Get some additional material parameters that are used in this sample
+		materials[i].alphaMode = glTFMaterial.alphaMode;
+		materials[i].alphaCutOff = (float)glTFMaterial.alphaCutoff;
+		materials[i].doubleSided = glTFMaterial.doubleSided;
+	}
+}
+
+void VulkanglTFScene::loadNode(const tinygltf::Node& inputNode, const tinygltf::Model& input, VulkanglTFScene::Node* parent, std::vector<uint32_t>& indexBuffer, std::vector<VulkanglTFScene::Vertex>& vertexBuffer)
+{
+	VulkanglTFScene::Node node{};
+	node.name = inputNode.name;
+	
+	// Get the local node matrix
+	// It's either made up from translation, rotation, scale or a 4x4 matrix
+	node.matrix = glm::mat4(1.0f);
+	if (inputNode.translation.size() == 3) {
+		node.matrix = glm::translate(node.matrix, glm::vec3(glm::make_vec3(inputNode.translation.data())));
+	}
+	if (inputNode.rotation.size() == 4) {
+		glm::quat q = glm::make_quat(inputNode.rotation.data());
+		node.matrix *= glm::mat4(q);
+	}
+	if (inputNode.scale.size() == 3) {
+		node.matrix = glm::scale(node.matrix, glm::vec3(glm::make_vec3(inputNode.scale.data())));
+	}
+	if (inputNode.matrix.size() == 16) {
+		node.matrix = glm::make_mat4x4(inputNode.matrix.data());
+	};
+
+	// Load node's children
+	if (inputNode.children.size() > 0) {
+		for (size_t i = 0; i < inputNode.children.size(); i++) {
+			loadNode(input.nodes[inputNode.children[i]], input, &node, indexBuffer, vertexBuffer);
+		}
+	}
+
+	// If the node contains mesh data, we load vertices and indices from the buffers
+	// In glTF this is done via accessors and buffer views
+	if (inputNode.mesh > -1) {
+		const tinygltf::Mesh mesh = input.meshes[inputNode.mesh];
+		// Iterate through all primitives of this node's mesh
+		for (size_t i = 0; i < mesh.primitives.size(); i++) {
+			const tinygltf::Primitive& glTFPrimitive = mesh.primitives[i];
+			uint32_t firstIndex = static_cast<uint32_t>(indexBuffer.size());
+			uint32_t vertexStart = static_cast<uint32_t>(vertexBuffer.size());
+			uint32_t indexCount = 0;
+			
+			// Vertex attributes
+			const float* positionBuffer = nullptr;
+			const float* normalsBuffer = nullptr;
+			const float* texCoordsBuffer = nullptr;
+			const float* tangentsBuffer = nullptr;
+			size_t vertexCount = 0;
+
+			// Get buffer data for vertex positions
+			if (glTFPrimitive.attributes.find("POSITION") != glTFPrimitive.attributes.end()) {
+				const tinygltf::Accessor& accessor = input.accessors[glTFPrimitive.attributes.find("POSITION")->second];
+				const tinygltf::BufferView& view = input.bufferViews[accessor.bufferView];
+				positionBuffer = reinterpret_cast<const float*>(&(input.buffers[view.buffer].data[accessor.byteOffset + view.byteOffset]));
+				vertexCount = accessor.count;
+			}
+			// Get buffer data for vertex normals
+			if (glTFPrimitive.attributes.find("NORMAL") != glTFPrimitive.attributes.end()) {
+				const tinygltf::Accessor& accessor = input.accessors[glTFPrimitive.attributes.find("NORMAL")->second];
+				const tinygltf::BufferView& view = input.bufferViews[accessor.bufferView];
+				normalsBuffer = reinterpret_cast<const float*>(&(input.buffers[view.buffer].data[accessor.byteOffset + view.byteOffset]));
+			}
+			// Get buffer data for vertex texture coordinates
+			// glTF supports multiple sets, we only load the first one
+			if (glTFPrimitive.attributes.find("TEXCOORD_0") != glTFPrimitive.attributes.end()) {
+				const tinygltf::Accessor& accessor = input.accessors[glTFPrimitive.attributes.find("TEXCOORD_0")->second];
+				const tinygltf::BufferView& view = input.bufferViews[accessor.bufferView];
+				texCoordsBuffer = reinterpret_cast<const float*>(&(input.buffers[view.buffer].data[accessor.byteOffset + view.byteOffset]));
+			}
+			// POI: This sample uses normal mapping, so we also need to load the tangents from the glTF file
+			if (glTFPrimitive.attributes.find("TANGENT") != glTFPrimitive.attributes.end()) {
+				const tinygltf::Accessor& accessor = input.accessors[glTFPrimitive.attributes.find("TANGENT")->second];
+				const tinygltf::BufferView& view = input.bufferViews[accessor.bufferView];
+				tangentsBuffer = reinterpret_cast<const float*>(&(input.buffers[view.buffer].data[accessor.byteOffset + view.byteOffset]));
+			}
+
+			// Append data to model's vertex buffer
+			for (size_t v = 0; v < vertexCount; v++) {
+
+				// Append interleaved attributes
+				Vertex vert{};
+				vert.pos = glm::vec4(glm::make_vec3(&positionBuffer[v * 3]), 1.0f);
+				vert.normal = glm::normalize(glm::vec3(normalsBuffer ? glm::make_vec3(&normalsBuffer[v * 3]) : glm::vec3(0.0f)));
+				vert.uv = texCoordsBuffer ? glm::make_vec2(&texCoordsBuffer[v * 2]) : glm::vec3(0.0f);
+				vert.tangent = tangentsBuffer ? glm::make_vec4(&tangentsBuffer[v * 4]) : glm::vec4(0.0f);
+ 				vertexBuffer.push_back(vert);
+
+				// Append separate attributes
+				vertexAttributes.pos.push_back(glm::make_vec3(&positionBuffer[v * 3]));
+				vertexAttributes.normal.push_back(glm::normalize(glm::vec3(normalsBuffer ? glm::make_vec3(&normalsBuffer[v * 3]) : glm::vec3(0.0f))));
+				vertexAttributes.tangent.push_back(tangentsBuffer ? glm::make_vec4(&tangentsBuffer[v * 4]) : glm::vec4(0.0f));
+				vertexAttributes.uv.push_back(texCoordsBuffer ? glm::make_vec2(&texCoordsBuffer[v * 2]) : glm::vec3(0.0f));
+
+			}
+
+			// Indices
+			const tinygltf::Accessor& accessor = input.accessors[glTFPrimitive.indices];
+			const tinygltf::BufferView& bufferView = input.bufferViews[accessor.bufferView];
+			const tinygltf::Buffer& buffer = input.buffers[bufferView.buffer];
+
+			indexCount += static_cast<uint32_t>(accessor.count);
+
+			// glTF supports different component types of indices
+			switch (accessor.componentType) {
+			case TINYGLTF_PARAMETER_TYPE_UNSIGNED_INT: {
+				const uint32_t* buf = reinterpret_cast<const uint32_t*>(&buffer.data[accessor.byteOffset + bufferView.byteOffset]);
+				for (size_t index = 0; index < accessor.count; index++) {
+					indexBuffer.push_back(buf[index] + vertexStart);
+				}
+				break;
+			}
+			case TINYGLTF_PARAMETER_TYPE_UNSIGNED_SHORT: {
+				const uint16_t* buf = reinterpret_cast<const uint16_t*>(&buffer.data[accessor.byteOffset + bufferView.byteOffset]);
+				for (size_t index = 0; index < accessor.count; index++) {
+					indexBuffer.push_back(buf[index] + vertexStart);
+				}
+				break;
+			}
+			case TINYGLTF_PARAMETER_TYPE_UNSIGNED_BYTE: {
+				const uint8_t* buf = reinterpret_cast<const uint8_t*>(&buffer.data[accessor.byteOffset + bufferView.byteOffset]);
+				for (size_t index = 0; index < accessor.count; index++) {
+					indexBuffer.push_back(buf[index] + vertexStart);
+				}
+				break;
+			}
+			default:
+				std::cerr << "Index component type " << accessor.componentType << " not supported!" << std::endl;
+				return;
+			}
+
+			Primitive primitive{};
+			primitive.firstIndex = firstIndex;
+			primitive.indexCount = indexCount;
+			primitive.materialIndex = glTFPrimitive.material;
+			node.mesh.primitives.push_back(primitive);
+		}
+	}
+
+	if (parent) {
+		parent->children.push_back(node);
+	}
+	else {
+		nodes.push_back(node);
+	}
+}
+
+VkDescriptorImageInfo VulkanglTFScene::getTextureDescriptor(const size_t index)
+{
+	return images[index].texture.descriptor;
+}
+
+/*
+	glTF rendering functions
+*/
+
+// Draw a single node including child nodes (if present)
+void VulkanglTFScene::drawNode(VkCommandBuffer commandBuffer, VkPipelineLayout pipelineLayout, VulkanglTFScene::Node node, bool separate)
+{
+	if (!node.visible) {
+		return;
+	}
+	if (node.mesh.primitives.size() > 0) {
+		// Pass the node's matrix via push constants
+		// Traverse the node hierarchy to the top-most parent to get the final matrix of the current node
+
+		PushConstBlock pushConstBlock;
+
+		glm::mat4 nodeMatrix = node.matrix;
+		VulkanglTFScene::Node* currentParent = node.parent;
+		while (currentParent) {
+			nodeMatrix = currentParent->matrix * nodeMatrix;
+			currentParent = currentParent->parent;
+		}
+		for (VulkanglTFScene::Primitive& primitive : node.mesh.primitives) {
+			if (primitive.indexCount > 0) {
+				VulkanglTFScene::Material& material = materials[primitive.materialIndex];
+				pushConstBlock.nodeMatrix = nodeMatrix;
+				pushConstBlock.alphaMask = (material.alphaMode == "MASK");
+				pushConstBlock.alphaMaskCutoff = material.alphaCutOff;
+				vkCmdPushConstants(commandBuffer, pipelineLayout, VK_SHADER_STAGE_VERTEX_BIT | VK_SHADER_STAGE_FRAGMENT_BIT, 0, sizeof(PushConstBlock), &pushConstBlock);
+				vkCmdBindDescriptorSets(commandBuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayout, 1, 1, &material.descriptorSet, 0, nullptr);
+				vkCmdDrawIndexed(commandBuffer, primitive.indexCount, 1, primitive.firstIndex, 0, 0);
+			}
+		}
+	}
+	for (auto& child : node.children) {
+		drawNode(commandBuffer, pipelineLayout, child, separate);
+	}
+}
+
+/*
+	Vulkan Example class
+*/
+
+VulkanExample::VulkanExample() : VulkanExampleBase(ENABLE_VALIDATION)
+{
+	title = "Separate vertex attribute buffers";
+	camera.type = Camera::CameraType::firstperson;
+	camera.flipY = true;
+	camera.setPosition(glm::vec3(0.0f, 1.0f, 0.0f));
+	camera.setRotation(glm::vec3(0.0f, -90.0f, 0.0f));
+	camera.setPerspective(60.0f, (float)width / (float)height, 0.1f, 256.0f);
+}
+
+VulkanExample::~VulkanExample()
+{
+	vkDestroyPipelineLayout(device, pipelineLayout, nullptr);
+	vkDestroyDescriptorSetLayout(device, descriptorSetLayouts.matrices, nullptr);
+	vkDestroyDescriptorSetLayout(device, descriptorSetLayouts.textures, nullptr);
+	shaderData.buffer.destroy();
+}
+
+void VulkanExample::getEnabledFeatures()
+{
+	enabledFeatures.samplerAnisotropy = deviceFeatures.samplerAnisotropy;
+}
+
+void VulkanExample::buildCommandBuffers()
+{
+	VkCommandBufferBeginInfo cmdBufInfo = vks::initializers::commandBufferBeginInfo();
+
+	VkClearValue clearValues[2];
+	clearValues[0].color = defaultClearColor;
+	clearValues[0].color = { { 0.25f, 0.25f, 0.25f, 1.0f } };;
+	clearValues[1].depthStencil = { 1.0f, 0 };
+
+	VkRenderPassBeginInfo renderPassBeginInfo = vks::initializers::renderPassBeginInfo();
+	renderPassBeginInfo.renderPass = renderPass;
+	renderPassBeginInfo.renderArea.offset.x = 0;
+	renderPassBeginInfo.renderArea.offset.y = 0;
+	renderPassBeginInfo.renderArea.extent.width = width;
+	renderPassBeginInfo.renderArea.extent.height = height;
+	renderPassBeginInfo.clearValueCount = 2;
+	renderPassBeginInfo.pClearValues = clearValues;
+
+	const VkViewport viewport = vks::initializers::viewport((float)width, (float)height, 0.0f, 1.0f);
+	const VkRect2D scissor = vks::initializers::rect2D(width, height, 0, 0);
+
+	for (int32_t i = 0; i < drawCmdBuffers.size(); ++i)
+	{
+		renderPassBeginInfo.framebuffer = frameBuffers[i];
+		VK_CHECK_RESULT(vkBeginCommandBuffer(drawCmdBuffers[i], &cmdBufInfo));
+		vkCmdBeginRenderPass(drawCmdBuffers[i], &renderPassBeginInfo, VK_SUBPASS_CONTENTS_INLINE);
+		vkCmdSetViewport(drawCmdBuffers[i], 0, 1, &viewport);
+		vkCmdSetScissor(drawCmdBuffers[i], 0, 1, &scissor);
+
+		// Select the separate or interleaved vertex binding pipeline
+		vkCmdBindPipeline(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, vertexAttributeSettings == VertexAttributeSettings::separate ? pipelines.vertexAttributesSeparate : pipelines.vertexAttributesInterleaved);
+
+		// Bind scene matrices descriptor to set 0
+		vkCmdBindDescriptorSets(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayout, 0, 1, &descriptorSet, 0, nullptr);
+
+		// Use the same index buffer, no matter how vertex attributes are passed
+		vkCmdBindIndexBuffer(drawCmdBuffers[i], glTFScene.indices.buffer, 0, VK_INDEX_TYPE_UINT32);
+
+		if (vertexAttributeSettings == VertexAttributeSettings::separate) {
+			// Using separate vertex attribute bindings requires binding all attribute buffers
+			VkDeviceSize offsets[4] = { 0, 0, 0, 0 };
+			std::array<VkBuffer, 4> buffers = { vertexAttibuteBuffers.pos.buffer, vertexAttibuteBuffers.normal.buffer, vertexAttibuteBuffers.uv.buffer, vertexAttibuteBuffers.tangent.buffer };
+			vkCmdBindVertexBuffers(drawCmdBuffers[i], 0, static_cast<uint32_t>(buffers.size()), buffers.data(), offsets);
+		} else {
+			// Using interleaved attribute bindings only requires one buffer bind
+			VkDeviceSize offsets[1] = { 0 };
+			vkCmdBindVertexBuffers(drawCmdBuffers[i], 0, 1, &glTFScene.vertices.buffer, offsets);
+		}
+		// Render all nodes starting at top-level
+		for (auto& node : glTFScene.nodes) {
+			glTFScene.drawNode(drawCmdBuffers[i], pipelineLayout, node, vertexAttributeSettings == VertexAttributeSettings::separate);
+		}
+
+		drawUI(drawCmdBuffers[i]);
+		vkCmdEndRenderPass(drawCmdBuffers[i]);
+		VK_CHECK_RESULT(vkEndCommandBuffer(drawCmdBuffers[i]));
+	}
+}
+
+void VulkanExample::loadglTFFile(std::string filename)
+{
+	tinygltf::Model glTFInput;
+	tinygltf::TinyGLTF gltfContext;
+	std::string error, warning;
+
+	this->device = device;
+
+#if defined(__ANDROID__)
+	// On Android all assets are packed with the apk in a compressed form, so we need to open them using the asset manager
+	// We let tinygltf handle this, by passing the asset manager of our app
+	tinygltf::asset_manager = androidApp->activity->assetManager;
+#endif
+	bool fileLoaded = gltfContext.LoadASCIIFromFile(&glTFInput, &error, &warning, filename);
+
+	// Pass some Vulkan resources required for setup and rendering to the glTF model loading class
+	glTFScene.vulkanDevice = vulkanDevice;
+	glTFScene.copyQueue    = queue;
+
+	size_t pos = filename.find_last_of('/');
+	glTFScene.path = filename.substr(0, pos);
+
+	std::vector<uint32_t> indexBuffer;
+	std::vector<VulkanglTFScene::Vertex> vertexBuffer;
+
+	if (!fileLoaded) {
+		vks::tools::exitFatal("Could not open the glTF file.\n\nThe file is part of the additional asset pack.\n\nRun \"download_assets.py\" in the repository root to download the latest version.", -1);
+		return;
+	}
+	glTFScene.loadImages(glTFInput);
+	glTFScene.loadMaterials(glTFInput);
+	glTFScene.loadTextures(glTFInput);
+	const tinygltf::Scene& scene = glTFInput.scenes[0];
+	for (size_t i = 0; i < scene.nodes.size(); i++) {
+		const tinygltf::Node node = glTFInput.nodes[scene.nodes[i]];
+		glTFScene.loadNode(node, glTFInput, nullptr, indexBuffer, vertexBuffer);
+	}
+
+	/* Upload vertex and index buffers */
+
+	/* Anonymous functions to simplify buffer creation */
+	/* Create a staging buffer used as a source for copies */
+	auto createStagingBuffer = [this](vks::Buffer& buffer, void* data, VkDeviceSize size) {
+		VK_CHECK_RESULT(vulkanDevice->createBuffer(VK_BUFFER_USAGE_TRANSFER_SRC_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, &buffer, size, data));
+	};
+	/* Create a device local buffer used as a target for copies*/
+	auto createDeviceBuffer = [this](vks::Buffer& buffer, VkDeviceSize size, VkBufferUsageFlags usageFlags = VK_BUFFER_USAGE_VERTEX_BUFFER_BIT) {
+		VK_CHECK_RESULT(vulkanDevice->createBuffer(usageFlags | VK_BUFFER_USAGE_TRANSFER_DST_BIT, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT, &buffer, size));
+	};
+
+	size_t vertexBufferSize = vertexBuffer.size() * sizeof(VulkanglTFScene::Vertex);
+	size_t indexBufferSize = indexBuffer.size() * sizeof(uint32_t);
+
+	vks::Buffer vertexStaging, indexStaging;
+
+	createStagingBuffer(indexStaging, indexBuffer.data(), indexBufferSize);
+	createStagingBuffer(vertexStaging, vertexBuffer.data(), vertexBufferSize);
+
+	createDeviceBuffer(glTFScene.indices, indexStaging.size, VK_BUFFER_USAGE_INDEX_BUFFER_BIT);
+	createDeviceBuffer(glTFScene.vertices, vertexStaging.size);
+
+	// Copy data from staging buffers (host) do device local buffer (gpu)
+	VkCommandBuffer copyCmd = vulkanDevice->createCommandBuffer(VK_COMMAND_BUFFER_LEVEL_PRIMARY, true);
+	VkBufferCopy copyRegion = {};
+
+	copyRegion.size = vertexBufferSize;
+	vkCmdCopyBuffer(copyCmd, vertexStaging.buffer, glTFScene.vertices.buffer, 1, &copyRegion);
+	
+	copyRegion.size = indexBufferSize;
+	vkCmdCopyBuffer(copyCmd, indexStaging.buffer, glTFScene.indices.buffer, 1, &copyRegion);
+
+	vulkanDevice->flushCommandBuffer(copyCmd, queue, true);
+
+	// Free staging resources
+	vkDestroyBuffer(device, vertexStaging.buffer, nullptr);
+	vkFreeMemory(device, vertexStaging.memory, nullptr);
+	vkDestroyBuffer(device, indexStaging.buffer, nullptr);
+	vkFreeMemory(device, indexStaging.memory, nullptr);
+
+	/*
+		Interleaved vertex attributes
+		We create one single buffer containing the interleaved vertex attributes
+	*/
+
+	/*
+		Separate vertex attributes
+		We create a separate buffer for each of the vertex attributes (position, normals, etc.)
+	*/
+
+	std::array<vks::Buffer, 4> stagingBuffers;
+	createStagingBuffer(stagingBuffers[0], glTFScene.vertexAttributes.pos.data(), glTFScene.vertexAttributes.pos.size() * sizeof(glTFScene.vertexAttributes.pos[0]));
+	createStagingBuffer(stagingBuffers[1], glTFScene.vertexAttributes.normal.data(), glTFScene.vertexAttributes.normal.size() * sizeof(glTFScene.vertexAttributes.normal[0]));
+	createStagingBuffer(stagingBuffers[2], glTFScene.vertexAttributes.uv.data(), glTFScene.vertexAttributes.uv.size() * sizeof(glTFScene.vertexAttributes.uv[0]));
+	createStagingBuffer(stagingBuffers[3], glTFScene.vertexAttributes.tangent.data(), glTFScene.vertexAttributes.tangent.size() * sizeof(glTFScene.vertexAttributes.tangent[0]));
+
+	createDeviceBuffer(vertexAttibuteBuffers.pos, stagingBuffers[0].size);
+	createDeviceBuffer(vertexAttibuteBuffers.normal, stagingBuffers[1].size);
+	createDeviceBuffer(vertexAttibuteBuffers.uv, stagingBuffers[2].size);
+	createDeviceBuffer(vertexAttibuteBuffers.tangent, stagingBuffers[3].size);
+
+	// Stage
+	std::vector<vks::Buffer> attributeBuffers = {
+		vertexAttibuteBuffers.pos,
+		vertexAttibuteBuffers.normal,
+		vertexAttibuteBuffers.uv,
+		vertexAttibuteBuffers.tangent,
+	};
+
+	// Copy data from staging buffers (host) do device local buffer (gpu)
+	copyCmd = vulkanDevice->createCommandBuffer(VK_COMMAND_BUFFER_LEVEL_PRIMARY, true);
+	copyRegion = {};
+	for (size_t i = 0; i < attributeBuffers.size(); i++) {
+		copyRegion.size = attributeBuffers[i].size;
+		vkCmdCopyBuffer(copyCmd, stagingBuffers[i].buffer, attributeBuffers[i].buffer, 1, &copyRegion);
+	}
+	vulkanDevice->flushCommandBuffer(copyCmd, queue, true);
+
+	/*
+		Index buffer
+		The index buffer is always the same, no matter how we pass the vertex attributes
+	*/
+
+
+	// @todo: clear
+}
+
+void VulkanExample::loadAssets()
+{
+	loadglTFFile(getAssetPath() + "models/sponza/sponza.gltf");
+}
+
+void VulkanExample::setupDescriptors()
+{
+	// One ubo to pass dynamic data to the shader
+	// Two combined image samplers per material as each material uses color and normal maps
+	std::vector<VkDescriptorPoolSize> poolSizes = {
+		vks::initializers::descriptorPoolSize(VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 1),
+		vks::initializers::descriptorPoolSize(VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, static_cast<uint32_t>(glTFScene.materials.size()) * 2),
+	};
+	// One set for matrices and one per model image/texture
+	const uint32_t maxSetCount = static_cast<uint32_t>(glTFScene.images.size()) + 1;
+	VkDescriptorPoolCreateInfo descriptorPoolInfo = vks::initializers::descriptorPoolCreateInfo(poolSizes, maxSetCount);
+	VK_CHECK_RESULT(vkCreateDescriptorPool(device, &descriptorPoolInfo, nullptr, &descriptorPool));
+	// Descriptor set layout for passing matrices
+	std::vector<VkDescriptorSetLayoutBinding> setLayoutBindings = {
+		vks::initializers::descriptorSetLayoutBinding(VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, VK_SHADER_STAGE_VERTEX_BIT, 0)
+	};
+	VkDescriptorSetLayoutCreateInfo descriptorSetLayoutCI = vks::initializers::descriptorSetLayoutCreateInfo(setLayoutBindings.data(), static_cast<uint32_t>(setLayoutBindings.size()));
+	VK_CHECK_RESULT(vkCreateDescriptorSetLayout(device, &descriptorSetLayoutCI, nullptr, &descriptorSetLayouts.matrices));
+	// Descriptor set layout for passing material textures
+	setLayoutBindings = {
+		// Color map
+		vks::initializers::descriptorSetLayoutBinding(VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, VK_SHADER_STAGE_FRAGMENT_BIT, 0),
+		// Normal map
+		vks::initializers::descriptorSetLayoutBinding(VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, VK_SHADER_STAGE_FRAGMENT_BIT, 1),
+	};
+	descriptorSetLayoutCI.pBindings = setLayoutBindings.data();
+	descriptorSetLayoutCI.bindingCount = 2;
+	VK_CHECK_RESULT(vkCreateDescriptorSetLayout(device, &descriptorSetLayoutCI, nullptr, &descriptorSetLayouts.textures));
+
+	// Pipeline layout using both descriptor sets (set 0 = matrices, set 1 = material)
+	std::array<VkDescriptorSetLayout, 2> setLayouts = { descriptorSetLayouts.matrices, descriptorSetLayouts.textures };
+	VkPipelineLayoutCreateInfo pipelineLayoutCI = vks::initializers::pipelineLayoutCreateInfo(setLayouts.data(), static_cast<uint32_t>(setLayouts.size()));
+	// We will use push constants to push the local matrices of a primitive to the vertex shader
+	VkPushConstantRange pushConstantRange = vks::initializers::pushConstantRange(VK_SHADER_STAGE_VERTEX_BIT | VK_SHADER_STAGE_FRAGMENT_BIT, sizeof(PushConstBlock), 0);
+	// Push constant ranges are part of the pipeline layout
+	pipelineLayoutCI.pushConstantRangeCount = 1;
+	pipelineLayoutCI.pPushConstantRanges = &pushConstantRange;
+	VK_CHECK_RESULT(vkCreatePipelineLayout(device, &pipelineLayoutCI, nullptr, &pipelineLayout));
+
+	// Descriptor set for scene matrices
+	VkDescriptorSetAllocateInfo allocInfo = vks::initializers::descriptorSetAllocateInfo(descriptorPool, &descriptorSetLayouts.matrices, 1);
+	VK_CHECK_RESULT(vkAllocateDescriptorSets(device, &allocInfo, &descriptorSet));
+	VkWriteDescriptorSet writeDescriptorSet = vks::initializers::writeDescriptorSet(descriptorSet, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 0, &shaderData.buffer.descriptor);
+	vkUpdateDescriptorSets(device, 1, &writeDescriptorSet, 0, nullptr);
+
+	// Descriptor sets for the materials
+	for (auto& material : glTFScene.materials) {
+		const VkDescriptorSetAllocateInfo allocInfo = vks::initializers::descriptorSetAllocateInfo(descriptorPool, &descriptorSetLayouts.textures, 1);
+		VK_CHECK_RESULT(vkAllocateDescriptorSets(device, &allocInfo, &material.descriptorSet));
+		VkDescriptorImageInfo colorMap = glTFScene.getTextureDescriptor(material.baseColorTextureIndex);
+		VkDescriptorImageInfo normalMap = glTFScene.getTextureDescriptor(material.normalTextureIndex);
+		std::vector<VkWriteDescriptorSet> writeDescriptorSets = {
+			vks::initializers::writeDescriptorSet(material.descriptorSet, VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 0, &colorMap),
+			vks::initializers::writeDescriptorSet(material.descriptorSet, VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 1, &normalMap),
+		};
+		vkUpdateDescriptorSets(device, static_cast<uint32_t>(writeDescriptorSets.size()), writeDescriptorSets.data(), 0, nullptr);
+	}
+}
+
+void VulkanExample::preparePipelines()
+{
+	VkPipelineInputAssemblyStateCreateInfo inputAssemblyStateCI = vks::initializers::pipelineInputAssemblyStateCreateInfo(VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST, 0, VK_FALSE);
+	VkPipelineRasterizationStateCreateInfo rasterizationStateCI = vks::initializers::pipelineRasterizationStateCreateInfo(VK_POLYGON_MODE_FILL, VK_CULL_MODE_BACK_BIT, VK_FRONT_FACE_COUNTER_CLOCKWISE, 0);
+	VkPipelineColorBlendAttachmentState blendAttachmentStateCI = vks::initializers::pipelineColorBlendAttachmentState(0xf, VK_FALSE);
+	VkPipelineColorBlendStateCreateInfo colorBlendStateCI = vks::initializers::pipelineColorBlendStateCreateInfo(1, &blendAttachmentStateCI);
+	VkPipelineDepthStencilStateCreateInfo depthStencilStateCI = vks::initializers::pipelineDepthStencilStateCreateInfo(VK_TRUE, VK_TRUE, VK_COMPARE_OP_LESS_OR_EQUAL);
+	VkPipelineViewportStateCreateInfo viewportStateCI = vks::initializers::pipelineViewportStateCreateInfo(1, 1, 0);
+	VkPipelineMultisampleStateCreateInfo multisampleStateCI = vks::initializers::pipelineMultisampleStateCreateInfo(VK_SAMPLE_COUNT_1_BIT, 0);
+	const std::vector<VkDynamicState> dynamicStateEnables = { VK_DYNAMIC_STATE_VIEWPORT, VK_DYNAMIC_STATE_SCISSOR };
+	VkPipelineDynamicStateCreateInfo dynamicStateCI = vks::initializers::pipelineDynamicStateCreateInfo(dynamicStateEnables.data(), static_cast<uint32_t>(dynamicStateEnables.size()), 0);
+	VkPipelineVertexInputStateCreateInfo vertexInputStateCI = vks::initializers::pipelineVertexInputStateCreateInfo();
+	std::array<VkPipelineShaderStageCreateInfo, 2> shaderStages;
+
+	// @todo: comment
+	const std::vector<VkVertexInputBindingDescription> vertexInputBindingsInterleaved = {
+		vks::initializers::vertexInputBindingDescription(0, sizeof(VulkanglTFScene::Vertex), VK_VERTEX_INPUT_RATE_VERTEX),
+	};
+	const std::vector<VkVertexInputAttributeDescription> vertexInputAttributesInterleaved = {
+		vks::initializers::vertexInputAttributeDescription(0, 0, VK_FORMAT_R32G32B32_SFLOAT, offsetof(VulkanglTFScene::Vertex, pos)),
+		vks::initializers::vertexInputAttributeDescription(0, 1, VK_FORMAT_R32G32B32_SFLOAT, offsetof(VulkanglTFScene::Vertex, normal)),
+		vks::initializers::vertexInputAttributeDescription(0, 2, VK_FORMAT_R32G32B32_SFLOAT, offsetof(VulkanglTFScene::Vertex, uv)),
+		vks::initializers::vertexInputAttributeDescription(0, 3, VK_FORMAT_R32G32B32_SFLOAT, offsetof(VulkanglTFScene::Vertex, tangent)),
+	};
+
+	// @todo: comment
+	const std::vector<VkVertexInputBindingDescription> vertexInputBindingsSeparate = {
+		vks::initializers::vertexInputBindingDescription(0, sizeof(glm::vec3), VK_VERTEX_INPUT_RATE_VERTEX),
+		vks::initializers::vertexInputBindingDescription(1, sizeof(glm::vec3), VK_VERTEX_INPUT_RATE_VERTEX),
+		vks::initializers::vertexInputBindingDescription(2, sizeof(glm::vec2), VK_VERTEX_INPUT_RATE_VERTEX),
+		vks::initializers::vertexInputBindingDescription(3, sizeof(glm::vec4), VK_VERTEX_INPUT_RATE_VERTEX),
+	};
+	const std::vector<VkVertexInputAttributeDescription> vertexInputAttributesSeparate = {
+		vks::initializers::vertexInputAttributeDescription(0, 0, VK_FORMAT_R32G32B32_SFLOAT, 0),
+		vks::initializers::vertexInputAttributeDescription(1, 1, VK_FORMAT_R32G32B32_SFLOAT, 0),
+		vks::initializers::vertexInputAttributeDescription(2, 2, VK_FORMAT_R32G32B32_SFLOAT, 0),
+		vks::initializers::vertexInputAttributeDescription(3, 3, VK_FORMAT_R32G32B32_SFLOAT, 0),
+	};
+
+	VkGraphicsPipelineCreateInfo pipelineCI = vks::initializers::pipelineCreateInfo(pipelineLayout, renderPass, 0);
+	pipelineCI.pVertexInputState = &vertexInputStateCI;
+	pipelineCI.pInputAssemblyState = &inputAssemblyStateCI;
+	pipelineCI.pRasterizationState = &rasterizationStateCI;
+	pipelineCI.pColorBlendState = &colorBlendStateCI;
+	pipelineCI.pMultisampleState = &multisampleStateCI;
+	pipelineCI.pViewportState = &viewportStateCI;
+	pipelineCI.pDepthStencilState = &depthStencilStateCI;
+	pipelineCI.pDynamicState = &dynamicStateCI;
+	pipelineCI.stageCount = static_cast<uint32_t>(shaderStages.size());
+	pipelineCI.pStages = shaderStages.data();
+
+	shaderStages[0] = loadShader(getShadersPath() + "vertexattributes/scene.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
+	shaderStages[1] = loadShader(getShadersPath() + "vertexattributes/scene.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);
+
+	//rasterizationStateCI.cullMode = material.doubleSided ? VK_CULL_MODE_NONE : VK_CULL_MODE_BACK_BIT;
+	vertexInputStateCI = vks::initializers::pipelineVertexInputStateCreateInfo(vertexInputBindingsInterleaved, vertexInputAttributesInterleaved);
+	VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCI, nullptr, &pipelines.vertexAttributesInterleaved));
+
+	vertexInputStateCI = vks::initializers::pipelineVertexInputStateCreateInfo(vertexInputBindingsSeparate, vertexInputAttributesSeparate);
+	VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCI, nullptr, &pipelines.vertexAttributesSeparate));
+}
+
+void VulkanExample::prepareUniformBuffers()
+{
+	VK_CHECK_RESULT(vulkanDevice->createBuffer(
+		VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT,
+		VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT,
+		&shaderData.buffer,
+		sizeof(shaderData.values)));
+	VK_CHECK_RESULT(shaderData.buffer.map());
+	updateUniformBuffers();
+}
+
+void VulkanExample::updateUniformBuffers()
+{
+	shaderData.values.projection = camera.matrices.perspective;
+	shaderData.values.view = camera.matrices.view;
+	shaderData.values.viewPos = camera.viewPos;
+	memcpy(shaderData.buffer.mapped, &shaderData.values, sizeof(shaderData.values));
+}
+
+void VulkanExample::prepare()
+{
+	VulkanExampleBase::prepare();
+	loadAssets();
+	prepareUniformBuffers();
+	setupDescriptors();
+	preparePipelines();
+	buildCommandBuffers();
+	prepared = true;
+}
+
+void VulkanExample::render()
+{
+	renderFrame();
+	if (camera.updated) {
+		updateUniformBuffers();
+	}
+}
+
+void VulkanExample::OnUpdateUIOverlay(vks::UIOverlay* overlay)
+{
+	if (overlay->header("Vertex buffer attributes")) {
+		bool interleaved = (vertexAttributeSettings == VertexAttributeSettings::interleaved);
+		bool separate = (vertexAttributeSettings == VertexAttributeSettings::separate);
+		if (overlay->radioButton("Interleaved", interleaved)) {
+			vertexAttributeSettings = VertexAttributeSettings::interleaved;
+			buildCommandBuffers();
+		}
+		if (overlay->radioButton("Separate", separate)) {
+			vertexAttributeSettings = VertexAttributeSettings::separate;
+			buildCommandBuffers();
+		}
+	}
+}
+
+VULKAN_EXAMPLE_MAIN()

examples/vertexattributes/vertexattributes.h

@@ -0,0 +1,176 @@
+/*
+ * Vulkan Example - Passing vertex attributes using interleaved and separate buffers
+ *
+ * Copyright (C) 2021 by Sascha Willems - www.saschawillems.de
+ *
+ * This code is licensed under the MIT license (MIT) (http://opensource.org/licenses/MIT)
+ */
+
+#define TINYGLTF_IMPLEMENTATION
+#define STB_IMAGE_IMPLEMENTATION
+#define TINYGLTF_NO_STB_IMAGE_WRITE
+#define TINYGLTF_NO_STB_IMAGE
+#define TINYGLTF_NO_EXTERNAL_IMAGE
+#ifdef VK_USE_PLATFORM_ANDROID_KHR
+#define TINYGLTF_ANDROID_LOAD_FROM_ASSETS
+#endif
+#include "tiny_gltf.h"
+
+#include "vulkanexamplebase.h"
+
+#define ENABLE_VALIDATION false
+
+struct PushConstBlock {
+	glm::mat4 nodeMatrix;
+	uint32_t alphaMask;
+	float alphaMaskCutoff;
+};
+
+ // Contains everything required to render a basic glTF scene in Vulkan
+ // This class is heavily simplified (compared to glTF's feature set) but retains the basic glTF structure
+class VulkanglTFScene
+{
+public:
+	// The class requires some Vulkan objects so it can create it's own resources
+	vks::VulkanDevice* vulkanDevice;
+	VkQueue copyQueue;
+
+	// The vertex layout for the samples' model
+	struct Vertex {
+		glm::vec3 pos;
+		glm::vec3 normal;
+		glm::vec2 uv;
+		glm::vec4 tangent;
+	};
+
+	// Single vertex buffer for all primitives
+	vks::Buffer vertices;
+
+	// Used at loading time
+	struct VertexAttributes {
+		std::vector<glm::vec2> uv;
+		std::vector<glm::vec3> pos, normal;
+		std::vector<glm::vec4> tangent;
+	} vertexAttributes;
+
+	// Single index buffer for all primitives
+	vks::Buffer indices;
+
+	// The following structures roughly represent the glTF scene structure
+	// To keep things simple, they only contain those properties that are required for this sample
+	struct Node;
+
+	// A primitive contains the data for a single draw call
+	struct Primitive {
+		uint32_t firstIndex;
+		uint32_t indexCount;
+		int32_t materialIndex;
+	};
+
+	// Contains the node's (optional) geometry and can be made up of an arbitrary number of primitives
+	struct Mesh {
+		std::vector<Primitive> primitives;
+	};
+
+	// A node represents an object in the glTF scene graph
+	struct Node {
+		Node* parent;
+		std::vector<Node> children;
+		Mesh mesh;
+		glm::mat4 matrix;
+		std::string name;
+		bool visible = true;
+	};
+
+	// A glTF material stores information in e.g. the texture that is attached to it and colors
+	struct Material {
+		glm::vec4 baseColorFactor = glm::vec4(1.0f);
+		uint32_t baseColorTextureIndex;
+		uint32_t normalTextureIndex;
+		std::string alphaMode = "OPAQUE";
+		float alphaCutOff;
+		bool doubleSided = false;
+		VkDescriptorSet descriptorSet;
+	};
+
+	// Contains the texture for a single glTF image
+	// Images may be reused by texture objects and are as such separated
+	struct Image {
+		vks::Texture2D texture;
+	};
+
+	// A glTF texture stores a reference to the image and a sampler
+	// In this sample, we are only interested in the image
+	struct Texture {
+		int32_t imageIndex;
+	};
+
+	/*
+		Model data
+	*/
+	std::vector<Image> images;
+	std::vector<Texture> textures;
+	std::vector<Material> materials;
+	std::vector<Node> nodes;
+
+	std::string path;
+
+	~VulkanglTFScene();
+	VkDescriptorImageInfo getTextureDescriptor(const size_t index);
+	void loadImages(tinygltf::Model& input);
+	void loadTextures(tinygltf::Model& input);
+	void loadMaterials(tinygltf::Model& input);
+	void loadNode(const tinygltf::Node& inputNode, const tinygltf::Model& input, VulkanglTFScene::Node* parent, std::vector<uint32_t>& indexBuffer, std::vector<VulkanglTFScene::Vertex>& vertexBuffer);
+	void drawNode(VkCommandBuffer commandBuffer, VkPipelineLayout pipelineLayout, VulkanglTFScene::Node node, bool separate);
+};
+
+class VulkanExample : public VulkanExampleBase
+{
+public:
+	VulkanglTFScene glTFScene;
+
+	enum VertexAttributeSettings { interleaved, separate };
+	VertexAttributeSettings vertexAttributeSettings = separate;
+
+	// Buffers for the separate vertex attributes
+	struct VertexAttributeBuffers {
+		vks::Buffer pos, normal, uv, tangent;
+	} vertexAttibuteBuffers;
+
+	struct ShaderData {
+		vks::Buffer buffer;
+		struct Values {
+			glm::mat4 projection;
+			glm::mat4 view;
+			glm::vec4 lightPos = glm::vec4(0.0f, 2.5f, 0.0f, 1.0f);
+			glm::vec4 viewPos;
+		} values;
+	} shaderData;
+
+	struct Pipelines {
+		VkPipeline vertexAttributesInterleaved;
+		VkPipeline vertexAttributesSeparate;
+	} pipelines;
+
+	VkPipelineLayout pipelineLayout;
+	VkDescriptorSet descriptorSet;
+
+	struct DescriptorSetLayouts {
+		VkDescriptorSetLayout matrices;
+		VkDescriptorSetLayout textures;
+	} descriptorSetLayouts;
+
+	VulkanExample();
+	~VulkanExample();
+	virtual void getEnabledFeatures();
+	void buildCommandBuffers();
+	void loadglTFFile(std::string filename);
+	void loadAssets();
+	void setupDescriptors();
+	void preparePipelines();
+	void prepareUniformBuffers();
+	void updateUniformBuffers();
+	void prepare();
+	virtual void render();
+	virtual void OnUpdateUIOverlay(vks::UIOverlay* overlay);
+};