Project 5: Guanlin Huang

README.md

@@ -3,10 +3,77 @@ Vulkan Grass Rendering
 
 **University of Pennsylvania, CIS 565: GPU Programming and Architecture, Project 5**
 
-* (TODO) YOUR NAME HERE
-* Tested on: (TODO) Windows 22, i7-2222 @ 2.22GHz 22GB, GTX 222 222MB (Moore 2222 Lab)
+* Guanlin Huang
+  * [LinkedIn](https://www.linkedin.com/in/guanlin-huang-4406668502/), [personal website](virulentkid.github.io/personal_web/index.html)
+* Tested on: Windows 11, i7-8750H CPU @ 3.5GHz 16GB, RTX2070 8GB; Compute Capability: 7.5
+
+## Overview
+This project uses Vulkan to simulate and render grass in real-time based on the following paper: [Responsive Real-Time Rendering for General 3D Scenes](https://www.cg.tuwien.ac.at/research/publications/2017/JAHRMANN-2017-RRTG/JAHRMANN-2017-RRTG-draft.pdf).
+![](img/display.gif) 
+
+## Background
+In most naturalistic environments, grass is significant. Due of the tremendous geometrical complexity of grass fields, which results in visual artifacts, the majority of interactive applications simulate fields of grass using image-based methods.
+
+In this project, each blade of grass is rendered as geometrical objects. Only the grass blades necessary for the visual look of the field of grass are rendered thanks to precise culling techniques and a flexible rendering pipeline. We also present a physical model that is assessed for every blade of grass. This makes it possible for a blade of grass to respond to its surroundings by accounting for the effects of gravity, wind, and collisions.
+
+## Grass Representation
+According to the paper, a single blade of grass may be described as a Bezier curve with the three control points v0, v1, and v2. The grass blade's base is specified in 3D by the base point (v0), the up direction is defined by the guiding curve (v1), which is always "above" v0, and the control points (v2) are where we apply various simulation forces. For more information, the paper gives a thorough usage for modifying fundamental 3D geometry forms for Bezier curve rendering.
+
+![](img/grass.png) 
+
+## Main Features
+1. **Simulation**: Force simulations (grass rebound, gravity and wind) which give the grass dynamics
+2. **Culling**: Grass blades that are not visually significant are removed to enhance performance.
+
+## Simmulation
+Gravity, grass recovery and wind force are simulated per blade in the simulation, which is performed in the compute shader.
+
+**Gravity**: In order to achieve the bending effect, an artificial gravity force is provided in addition to the natural gravity force that pulls the blade downward. 
+**Recovery**: The grass blades will be prevented from falling to the ground by applying the recovery force, which works like a mass-spring system.
+**Wind**: The wind is generated using a random-number-generating noise function.
+
+Together, the result grass looks pretty realistic.
+
+Grass with no force:
+
+![](img/no_force.png)
+
+Grass with force simulation
+
+![](img/res.gif) 
+
+## Culling
+
+### Orientation Culling
+Blades with a width direction parallel to the view direction are removed by orientation culling. As the camera is pointed in the image below, we can see that some blades vanish at a particular viewing angle. (Try concentrating solely on one blade to observe the effect.)
+
+![](img/ori_cull.gif) 
+
+### Frustum Culling
+View-frustum culling will remove the grass blades outside of the view frustum.
+
+![](img/frustum_cull.gif)
+
+### Distance Culling
+Last but not least, the distance culling process removes blades according on how far the blade is from the camera (projected on to the ground plane). A particular percentage of the blades in the distance level bucket, which is where the blade distance is discretized, will be removed. More blades will be removed the farther the distance level is from the camera.
+
+![](img/dist_cull.gif) 
+
+## Performance Analysis
+### Number of blades V.S. Frames per Second
+The FPS is measured using Windows built-in tool (Win + G)
+
+The implementation was tested with and without culling procedures using various numbers of blades. As anticipated, we observe that the FPS falls as the number of blades rises (by a factor of 4).
+
+![](img/p1.png)
+
+### Different Culling Operations V.S. Frames per Second
+Each culling operation is used solely for performance measurement in order to comprehend the effects of that operation.
+
+![](img/p2.png)
+
+
+
+
 
-### (TODO: Your README)
 
-*DO NOT* leave the README to the last minute! It is a crucial part of the
-project, and we will not be able to grade you without a good README.

src/Blades.h

@@ -4,7 +4,7 @@
 #include <array>
 #include "Model.h"
 
-constexpr static unsigned int NUM_BLADES = 1 << 13;
+constexpr static unsigned int NUM_BLADES = 1 <<18;
 constexpr static float MIN_HEIGHT = 1.3f;
 constexpr static float MAX_HEIGHT = 2.5f;
 constexpr static float MIN_WIDTH = 0.1f;

src/Renderer.cpp

@@ -198,6 +198,59 @@ void Renderer::CreateComputeDescriptorSetLayout() {
     // TODO: Create the descriptor set layout for the compute pipeline
     // Remember this is like a class definition stating why types of information
     // will be stored at each binding
+    VkDescriptorSetLayoutBinding bladesLayoutBinding = {};
+    bladesLayoutBinding.binding = 0;
+    bladesLayoutBinding.descriptorType = VK_DESCRIPTOR_TYPE_STORAGE_BUFFER;
+    bladesLayoutBinding.descriptorCount = 1;
+    bladesLayoutBinding.stageFlags = VK_SHADER_STAGE_COMPUTE_BIT;
+    bladesLayoutBinding.pImmutableSamplers = nullptr;
+
+    VkDescriptorSetLayoutBinding culledBladesLayoutBinding = {};
+    culledBladesLayoutBinding.binding = 1;
+    culledBladesLayoutBinding.descriptorType = VK_DESCRIPTOR_TYPE_STORAGE_BUFFER;
+    culledBladesLayoutBinding.descriptorCount = 1;
+    culledBladesLayoutBinding.stageFlags = VK_SHADER_STAGE_COMPUTE_BIT;
+    culledBladesLayoutBinding.pImmutableSamplers = nullptr;
+
+    VkDescriptorSetLayoutBinding numBladesLayoutBinding = {};
+    numBladesLayoutBinding.binding = 2;
+    numBladesLayoutBinding.descriptorType = VK_DESCRIPTOR_TYPE_STORAGE_BUFFER;
+    numBladesLayoutBinding.descriptorCount = 1;
+    numBladesLayoutBinding.stageFlags = VK_SHADER_STAGE_COMPUTE_BIT;
+    numBladesLayoutBinding.pImmutableSamplers = nullptr;
+
+    std::vector<VkDescriptorSetLayoutBinding> bindings = { bladesLayoutBinding, culledBladesLayoutBinding, numBladesLayoutBinding };
+
+    // Create the descriptor set layout
+    VkDescriptorSetLayoutCreateInfo layoutInfo = {};
+    layoutInfo.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO;
+    layoutInfo.bindingCount = static_cast<uint32_t>(bindings.size());
+    layoutInfo.pBindings = bindings.data();
+
+    if (vkCreateDescriptorSetLayout(logicalDevice, &layoutInfo, nullptr, &computeDescriptorSetLayout) != VK_SUCCESS) {
+        throw std::runtime_error("Failed to create descriptor set layout");
+    }
+}
+
+void Renderer::CreateGrassDescriptorSetLayout() {
+    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;
+
+    std::vector<VkDescriptorSetLayoutBinding> bindings = { uboLayoutBinding };
+
+    // Create the descriptor set layout
+    VkDescriptorSetLayoutCreateInfo layoutInfo = {};
+    layoutInfo.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO;
+    layoutInfo.bindingCount = static_cast<uint32_t>(bindings.size());
+    layoutInfo.pBindings = bindings.data();
+
+    if (vkCreateDescriptorSetLayout(logicalDevice, &layoutInfo, nullptr, &grassDescriptorSetLayout) != VK_SUCCESS) {
+        throw std::runtime_error("Failed to create descriptor set layout");
+    }
 }
 
 void Renderer::CreateDescriptorPool() {
@@ -216,6 +269,7 @@ void Renderer::CreateDescriptorPool() {
         { VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER , 1 },
 
         // TODO: Add any additional types and counts of descriptors you will need to allocate
+        { VK_DESCRIPTOR_TYPE_STORAGE_BUFFER , static_cast<uint32_t>(scene->GetBlades().size() * 3) },
     };
 
     VkDescriptorPoolCreateInfo poolInfo = {};
@@ -320,6 +374,42 @@ void Renderer::CreateModelDescriptorSets() {
 void Renderer::CreateGrassDescriptorSets() {
     // TODO: Create Descriptor sets for the grass.
     // This should involve creating descriptor sets which point to the model matrix of each group of grass blades
+    grassDescriptorSets.resize(scene->GetBlades().size());
+
+    // Describe the desciptor set
+    VkDescriptorSetLayout layouts[] = { modelDescriptorSetLayout };
+    VkDescriptorSetAllocateInfo allocInfo = {};
+    allocInfo.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO;
+    allocInfo.descriptorPool = descriptorPool;
+    allocInfo.descriptorSetCount = static_cast<uint32_t>(grassDescriptorSets.size());
+    allocInfo.pSetLayouts = layouts;
+
+    // Allocate descriptor sets
+    if (vkAllocateDescriptorSets(logicalDevice, &allocInfo, grassDescriptorSets.data()) != VK_SUCCESS) {
+        throw std::runtime_error("Failed to allocate descriptor set");
+    }
+
+    std::vector<VkWriteDescriptorSet> descriptorWrites(grassDescriptorSets.size());
+
+    for (uint32_t i = 0; i < scene->GetBlades().size(); ++i) {
+        VkDescriptorBufferInfo modelBufferInfo = {};
+        modelBufferInfo.buffer = scene->GetBlades()[i]->GetModelBuffer();
+        modelBufferInfo.offset = 0;
+        modelBufferInfo.range = sizeof(ModelBufferObject);
+
+        descriptorWrites[i].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
+        descriptorWrites[i].dstSet = grassDescriptorSets[i];
+        descriptorWrites[i].dstBinding = 0;
+        descriptorWrites[i].dstArrayElement = 0;
+        descriptorWrites[i].descriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
+        descriptorWrites[i].descriptorCount = 1;
+        descriptorWrites[i].pBufferInfo = &modelBufferInfo;
+        descriptorWrites[i].pImageInfo = nullptr;
+        descriptorWrites[i].pTexelBufferView = nullptr;
+    }
+
+    // Update descriptor sets
+    vkUpdateDescriptorSets(logicalDevice, static_cast<uint32_t>(descriptorWrites.size()), descriptorWrites.data(), 0, nullptr);
 }
 
 void Renderer::CreateTimeDescriptorSet() {
@@ -360,6 +450,70 @@ void Renderer::CreateTimeDescriptorSet() {
 void Renderer::CreateComputeDescriptorSets() {
     // TODO: Create Descriptor sets for the compute pipeline
     // The descriptors should point to Storage buffers which will hold the grass blades, the culled grass blades, and the output number of grass blades 
+    computeDescriptorSets.resize(scene->GetBlades().size());
+
+    // Describe the desciptor set
+    VkDescriptorSetLayout layouts[] = { computeDescriptorSetLayout };
+    VkDescriptorSetAllocateInfo allocInfo = {};
+    allocInfo.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO;
+    allocInfo.descriptorPool = descriptorPool;
+    allocInfo.descriptorSetCount = static_cast<uint32_t>(computeDescriptorSets.size());
+    allocInfo.pSetLayouts = layouts;;
+    allocInfo.pSetLayouts = layouts;
+
+    // Allocate descriptor sets
+    if (vkAllocateDescriptorSets(logicalDevice, &allocInfo, computeDescriptorSets.data()) != VK_SUCCESS) {
+        throw std::runtime_error("Failed to allocate descriptor set");
+    }
+
+    std::vector<VkWriteDescriptorSet> descriptorWrites(3 * computeDescriptorSets.size());
+
+    for (uint32_t i = 0; i < scene->GetBlades().size(); ++i) {
+        VkDescriptorBufferInfo bladesBufferInfo = {};
+        bladesBufferInfo.buffer = scene->GetBlades()[i]->GetBladesBuffer();
+        bladesBufferInfo.offset = 0;
+        bladesBufferInfo.range = sizeof(Blade) * NUM_BLADES;
+
+        VkDescriptorBufferInfo culledBladesBufferInfo = {};
+        culledBladesBufferInfo.buffer = scene->GetBlades()[i]->GetCulledBladesBuffer();
+        culledBladesBufferInfo.offset = 0;
+        culledBladesBufferInfo.range = sizeof(Blade) * NUM_BLADES;
+
+        VkDescriptorBufferInfo numBladesBufferInfo = {};
+        numBladesBufferInfo.buffer = scene->GetBlades()[i]->GetNumBladesBuffer();
+        numBladesBufferInfo.offset = 0;
+        numBladesBufferInfo.range = sizeof(BladeDrawIndirect);
+
+        descriptorWrites[3 * i + 0].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
+        descriptorWrites[3 * i + 0].dstSet = computeDescriptorSets[i];
+        descriptorWrites[3 * i + 0].dstBinding = 0;
+        descriptorWrites[3 * i + 0].descriptorType = VK_DESCRIPTOR_TYPE_STORAGE_BUFFER;
+        descriptorWrites[3 * i + 0].descriptorCount = 1;
+        descriptorWrites[3 * i + 0].pBufferInfo = &bladesBufferInfo;
+        descriptorWrites[3 * i + 0].pImageInfo = nullptr;
+        descriptorWrites[3 * i + 0].pTexelBufferView = nullptr;
+
+        descriptorWrites[3 * i + 1].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
+        descriptorWrites[3 * i + 1].dstSet = computeDescriptorSets[i];
+        descriptorWrites[3 * i + 1].dstBinding = 1;
+        descriptorWrites[3 * i + 1].descriptorType = VK_DESCRIPTOR_TYPE_STORAGE_BUFFER;
+        descriptorWrites[3 * i + 1].descriptorCount = 1;
+        descriptorWrites[3 * i + 1].pBufferInfo = &culledBladesBufferInfo;
+        descriptorWrites[3 * i + 1].pImageInfo = nullptr;
+        descriptorWrites[3 * i + 1].pTexelBufferView = nullptr;
+
+        descriptorWrites[3 * i + 2].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
+        descriptorWrites[3 * i + 2].dstSet = computeDescriptorSets[i];
+        descriptorWrites[3 * i + 2].dstBinding = 2;
+        descriptorWrites[3 * i + 2].descriptorType = VK_DESCRIPTOR_TYPE_STORAGE_BUFFER;
+        descriptorWrites[3 * i + 2].descriptorCount = 1;
+        descriptorWrites[3 * i + 2].pBufferInfo = &numBladesBufferInfo;
+        descriptorWrites[3 * i + 2].pImageInfo = nullptr;
+        descriptorWrites[3 * i + 2].pTexelBufferView = nullptr;
+    }
+
+    // Update descriptor sets
+    vkUpdateDescriptorSets(logicalDevice, static_cast<uint32_t>(descriptorWrites.size()), descriptorWrites.data(), 0, nullptr);
 }
 
 void Renderer::CreateGraphicsPipeline() {
@@ -717,7 +871,8 @@ void Renderer::CreateComputePipeline() {
     computeShaderStageInfo.pName = "main";
 
     // TODO: Add the compute dsecriptor set layout you create to this list
-    std::vector<VkDescriptorSetLayout> descriptorSetLayouts = { cameraDescriptorSetLayout, timeDescriptorSetLayout };
+    //std::vector<VkDescriptorSetLayout> descriptorSetLayouts = { cameraDescriptorSetLayout, timeDescriptorSetLayout };
+    std::vector<VkDescriptorSetLayout> descriptorSetLayouts = { cameraDescriptorSetLayout, timeDescriptorSetLayout, computeDescriptorSetLayout };
 
     // Create pipeline layout
     VkPipelineLayoutCreateInfo pipelineLayoutInfo = {};
@@ -884,6 +1039,10 @@ void Renderer::RecordComputeCommandBuffer() {
     vkCmdBindDescriptorSets(computeCommandBuffer, VK_PIPELINE_BIND_POINT_COMPUTE, computePipelineLayout, 1, 1, &timeDescriptorSet, 0, nullptr);
 
     // TODO: For each group of blades bind its descriptor set and dispatch
+    for (uint32_t j = 0; j < scene->GetBlades().size(); ++j) {
+        vkCmdBindDescriptorSets(computeCommandBuffer, VK_PIPELINE_BIND_POINT_COMPUTE, computePipelineLayout, 2, 1, &computeDescriptorSets[j], 0, nullptr);
+        vkCmdDispatch(computeCommandBuffer, NUM_BLADES / 32, 1, 1);
+    }
 
     // ~ End recording ~
     if (vkEndCommandBuffer(computeCommandBuffer) != VK_SUCCESS) {
@@ -976,13 +1135,14 @@ void Renderer::RecordCommandBuffers() {
             VkBuffer vertexBuffers[] = { scene->GetBlades()[j]->GetCulledBladesBuffer() };
             VkDeviceSize offsets[] = { 0 };
             // TODO: Uncomment this when the buffers are populated
-            // vkCmdBindVertexBuffers(commandBuffers[i], 0, 1, vertexBuffers, offsets);
+            vkCmdBindVertexBuffers(commandBuffers[i], 0, 1, vertexBuffers, offsets);
 
             // TODO: Bind the descriptor set for each grass blades model
+            vkCmdBindDescriptorSets(commandBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, grassPipelineLayout, 1, 1, &grassDescriptorSets[j], 0, nullptr);
 
             // Draw
             // TODO: Uncomment this when the buffers are populated
-            // vkCmdDrawIndirect(commandBuffers[i], scene->GetBlades()[j]->GetNumBladesBuffer(), 0, 1, sizeof(BladeDrawIndirect));
+            vkCmdDrawIndirect(commandBuffers[i], scene->GetBlades()[j]->GetNumBladesBuffer(), 0, 1, sizeof(BladeDrawIndirect));
         }
 
         // End render pass
@@ -1042,6 +1202,7 @@ Renderer::~Renderer() {
     vkDeviceWaitIdle(logicalDevice);
 
     // TODO: destroy any resources you created
+    vkDestroyDescriptorSetLayout(logicalDevice, computeDescriptorSetLayout, nullptr);
 
     vkFreeCommandBuffers(logicalDevice, graphicsCommandPool, static_cast<uint32_t>(commandBuffers.size()), commandBuffers.data());
     vkFreeCommandBuffers(logicalDevice, computeCommandPool, 1, &computeCommandBuffer);

src/Renderer.h

@@ -19,6 +19,7 @@ class Renderer {
     void CreateModelDescriptorSetLayout();
     void CreateTimeDescriptorSetLayout();
     void CreateComputeDescriptorSetLayout();
+    void CreateGrassDescriptorSetLayout();
 
     void CreateDescriptorPool();
 
@@ -56,12 +57,16 @@ class Renderer {
     VkDescriptorSetLayout cameraDescriptorSetLayout;
     VkDescriptorSetLayout modelDescriptorSetLayout;
     VkDescriptorSetLayout timeDescriptorSetLayout;
-
+    VkDescriptorSetLayout grassDescriptorSetLayout;
+    VkDescriptorSetLayout computeDescriptorSetLayout;
+
     VkDescriptorPool descriptorPool;
 
     VkDescriptorSet cameraDescriptorSet;
     std::vector<VkDescriptorSet> modelDescriptorSets;
     VkDescriptorSet timeDescriptorSet;
+    std::vector<VkDescriptorSet> grassDescriptorSets;
+    std::vector<VkDescriptorSet> computeDescriptorSets;
 
     VkPipelineLayout graphicsPipelineLayout;
     VkPipelineLayout grassPipelineLayout;

src/main.cpp

@@ -1,4 +1,5 @@
 #include <vulkan/vulkan.h>
+#include <sstream>
 #include "Instance.h"
 #include "Window.h"
 #include "Renderer.h"