diff --git a/README.md b/README.md index fc0e545..0839e75 100644 --- a/README.md +++ b/README.md @@ -1,300 +1,99 @@ -Instructions - Vulkan Grass Rendering +Vulkan Grass Rendering ======================== -This is due **Sunday 11/4, evening at midnight**. +**University of Pennsylvania, CIS 565: GPU Programming and Architecture, Project 5** -**Summary:** -In this project, you will use Vulkan to implement a grass simulator and renderer. You will -use compute shaders to perform physics calculations on Bezier curves that represent individual -grass blades in your application. Since rendering every grass blade on every frame will is fairly -inefficient, you will also use compute shaders to cull grass blades that don't contribute to a given frame. -The remaining blades will be passed to a graphics pipeline, in which you will write several shaders. -You will write a vertex shader to transform Bezier control points, tessellation shaders to dynamically create -the grass geometry from the Bezier curves, and a fragment shader to shade the grass blades. +* Jie Meng + * [LinkedIn](https://www.linkedin.com/in/jie-meng/), [YouTube](https://www.youtube.com/channel/UC7G8fUcQrrI_1YnXY5sQM6A). +* Tested on: Windows 10, i7-7700HQ @ 2.80GHz, 16GB, GTX 1050 4GB (Personal Laptop) -The base code provided includes all of the basic Vulkan setup, including a compute pipeline that will run your compute -shaders and two graphics pipelines, one for rendering the geometry that grass will be placed on and the other for -rendering the grass itself. Your job will be to write the shaders for the grass graphics pipeline and the compute pipeline, -as well as binding any resources (descriptors) you may need to accomplish the tasks described in this assignment. -![](img/grass.gif) ![](img/grass2.gif) +### Demo gif -You are not required to use this base code if you don't want -to. You may also change any part of the base code as you please. -**This is YOUR project.** The above .gifs are just examples that you -can use as a reference to compare to. Feel free to get creative with your implementations! +#### Still view +------------------------ +![](img/g1.gif) +----------------------- -**Important:** -- If you are not in CGGT/DMD, you may replace this project with a GPU compute -project. You MUST get this pre-approved by Ottavio before continuing! +#### Motion View +--------------------------- +![](img/g2.gif) +------------------------ -### Contents +Does it remind you of [Breath of the Wild](https://www.google.com/search?q=legend+of+zelda+breath+of+the+wild+grass&source=lnms&tbm=isch&sa=X&ved=0ahUKEwj58aWhrbzeAhVJmeAKHUi-DW0Q_AUIFCgC&biw=1396&bih=686#imgrc=1mbfVXdFsBjPbM:) ? -* `src/` C++/Vulkan source files. - * `shaders/` glsl shader source files - * `images/` images used as textures within graphics pipelines -* `external/` Includes and static libraries for 3rd party libraries. -* `img/` Screenshots and images to use in your READMEs +Project Summary +====================== -### Installing Vulkan +### Description +This project is an Vulkan implementation of the I3D paper: [Responsive Real-Time Grass Rendering for General 3D Scenes](https://www.cg.tuwien.ac.at/research/publications/2017/JAHRMANN-2017-RRTG/JAHRMANN-2017-RRTG-draft.pdf). -In order to run a Vulkan project, you first need to download and install the [Vulkan SDK](https://vulkan.lunarg.com/). -Make sure to run the downloaded installed as administrator so that the installer can set the appropriate environment -variables for you. +Follow the steps in the paper, a grass is represented as a Bezier curve with width (essentially a quad). A compute shader is created to handle physics calculation and culling. Such that all grass blades are processed in parallel. After computation, the unculled blades are pass to graphics pipeline, and effectively become meshes after tessellation, which are then rendered to screen. -Once you have done this, you need to make sure your GPU driver supports Vulkan. Download and install a -[Vulkan driver](https://developer.nvidia.com/vulkan-driver) from NVIDIA's website. +### Result images -Finally, to check that Vulkan is ready for use, go to your Vulkan SDK directory (`C:/VulkanSDK/` unless otherwise specified) -and run the `cube.exe` example within the `Bin` directory. IF you see a rotating gray cube with the LunarG logo, then you -are all set! +_Configuration: 100x100 underlying plane, 2^21 grass blades_ -### Running the code +View 1: -While developing your grass renderer, you will want to keep validation layers enabled so that error checking is turned on. -The project is set up such that when you are in `debug` mode, validation layers are enabled, and when you are in `release` mode, -validation layers are disabled. After building the code, you should be able to run the project without any errors. You will see a plane with a grass texture on it to begin with. +![](img/g11.png) +------------------------ -![](img/cube_demo.png) +View 2: -## Requirements +![](img/g22.png) +------------------------ -**Ask on the mailing list for any clarifications.** -In this project, you are given the following code: +### Compute Shader -* The basic setup for a Vulkan project, including the swapchain, physical device, logical device, and the pipelines described above. -* Structs for some of the uniform buffers you will be using. -* Some buffer creation utility functions. -* A simple interactive camera using the mouse. +The compute shader mainly has two parts: first apply force and update positions; then cull unnecessary blades out. -You need to implement the following features/pipeline stages: + * The force applied on each grass including gravity, recovery force (treat grass as elastic object) and external wind force. Essentially, these forces are accelerations. The postion of the top of a blade is updated given such acceleration and elapsed time. -* Compute shader (`shaders/compute.comp`) -* Grass pipeline stages - * Vertex shader (`shaders/grass.vert') - * Tessellation control shader (`shaders/grass.tesc`) - * Tessellation evaluation shader (`shaders/grass.tese`) - * Fragment shader (`shaders/grass.frag`) -* Binding of any extra descriptors you may need + * In the culling stage, three culling scehmes are used together: first cull the blades that face backwards; then cull the blades outside frustum; finally cull the blades that are too far away. -See below for more guidance. +### Graphics Shders -## Base Code Tour +After compute shader, we have information of the shapes of blades at current frame. We go through several stages to render it out: (only programmable stages are listed) -Areas that you need to complete are -marked with a `TODO` comment. Functions that are useful -for reference are marked with the comment `CHECKITOUT`. + * Vertex shader: only perform model transformation here, since we have tessellation shaders + * Tessellation Control shader: pass data from vertex shader to next stage, set tessellation levels according to distance: nearer blades have finer tessellation levels, farther blades have relatively rough ones. + * Tessellation Evaluation shader: after tessellation, given (u,v) values, calculate fragment positions. Also, the paper uses function transformations to render quad blades into different shapes, like triangles, quadratics, etc. + * Fragment shader: color the fragment using lambertian shading -* `src/main.cpp` is the entry point of our application. -* `src/Instance.cpp` sets up the application state, initializes the Vulkan library, and contains functions that will create our -physical and logical device handles. -* `src/Device.cpp` manages the logical device and sets up the queues that our command buffers will be submitted to. -* `src/Renderer.cpp` contains most of the rendering implementation, including Vulkan setup and resource creation. You will -likely have to make changes to this file in order to support changes to your pipelines. -* `src/Camera.cpp` manages the camera state. -* `src/Model.cpp` manages the state of the model that grass will be created on. Currently a plane is hardcoded, but feel free to -update this with arbitrary model loading! -* `src/Blades.cpp` creates the control points corresponding to the grass blades. There are many parameters that you can play with -here that will change the behavior of your rendered grass blades. -* `src/Scene.cpp` manages the scene state, including the model, blades, and simualtion time. -* `src/BufferUtils.cpp` provides helper functions for creating buffers to be used as descriptors. +**Illustration on Tessellation Levels** -We left out descriptions for a couple files that you likely won't have to modify. Feel free to investigate them to understand their -importance within the scope of the project. +High | Low +------|------- +![](img/tese1.png) | ![](img/tese2.png) -## Grass Rendering -This project is an implementation of the paper, [Responsive Real-Time Grass Rendering for General 3D Scenes](https://www.cg.tuwien.ac.at/research/publications/2017/JAHRMANN-2017-RRTG/JAHRMANN-2017-RRTG-draft.pdf). -Please make sure to use this paper as a primary resource while implementing your grass renderers. It does a great job of explaining -the key algorithms and math you will be using. Below is a brief description of the different components in chronological order of how your renderer will -execute, but feel free to develop the components in whatever order you prefer. +Analysis +==================== -We recommend starting with trying to display the grass blades without any forces on them before trying to add any forces on the blades themselves. Here is an example of what that may look like: +**_Configuration: 1280x960 window, 100x100 underlying plane, 2^18 grass blades_** -![](img/grass_basic.gif) +### Grass Blades number -### Representing Grass as Bezier Curves +![](img/performance1.png) -In this project, grass blades will be represented as Bezier curves while performing physics calculations and culling operations. -Each Bezier curve has three control points. -* `v0`: the position of the grass blade on the geomtry -* `v1`: a Bezier curve guide that is always "above" `v0` with respect to the grass blade's up vector (explained soon) -* `v2`: a physical guide for which we simulate forces on +As number of blades goes up, it takes longer time to render. But overall, the performance is very good: even at like 2^21 (about 2M blades), it still gives very good FPS. Besides, here only very simple culling is used, so there is still a large space to improve performance further. -We also need to store per-blade characteristics that will help us simulate and tessellate our grass blades correctly. -* `up`: the blade's up vector, which corresponds to the normal of the geometry that the grass blade resides on at `v0` -* Orientation: the orientation of the grass blade's face -* Height: the height of the grass blade -* Width: the width of the grass blade's face -* Stiffness coefficient: the stiffness of our grass blade, which will affect the force computations on our blade +### Culling Methods -We can pack all this data into four `vec4`s, such that `v0.w` holds orientation, `v1.w` holds height, `v2.w` holds width, and -`up.w` holds the stiffness coefficient. +**Fixed camera position and view angle to control variable in this test** -![](img/blade_model.jpg) +![](img/performance1.png) -### Simulating Forces +Here the orientation culling doesn't make a big difference. I guess it's because the culling threshold (0.01) is not small enough, or maybe I happen to choose a bad view for orientation culling. On the other hand, View-frustum and distance culling work better, I believe it's still relying on the camera view. Overall the culling stage performs well: with all culling methods on, we saved about 40% render time. -In this project, you will be simulating forces on grass blades while they are still Bezier curves. This will be done in a compute -shader using the compute pipeline that has been created for you. Remember that `v2` is our physical guide, so we will be -applying transformations to `v2` initially, then correcting for potential errors. We will finally update `v1` to maintain the appropriate -length of our grass blade. -#### Binding Resources -In order to update the state of your grass blades on every frame, you will need to create a storage buffer to maintain the grass data. -You will also need to pass information about how much time has passed in the simulation and the time since the last frame. To do this, -you can extend or create descriptor sets that will be bound to the compute pipeline. - -#### Gravity - -Given a gravity direction, `D.xyz`, and the magnitude of acceleration, `D.w`, we can compute the environmental gravity in -our scene as `gE = normalize(D.xyz) * D.w`. - -We then determine the contribution of the gravity with respect to the front facing direction of the blade, `f`, -as a term called the "front gravity". Front gravity is computed as `gF = (1/4) * ||gE|| * f`. - -We can then determine the total gravity on the grass blade as `g = gE + gF`. - -#### Recovery - -Recovery corresponds to the counter-force that brings our grass blade back into equilibrium. This is derived in the paper using Hooke's law. -In order to determine the recovery force, we need to compare the current position of `v2` to its original position before -simulation started, `iv2`. At the beginning of our simulation, `v1` and `v2` are initialized to be a distance of the blade height along the `up` vector. - -Once we have `iv2`, we can compute the recovery forces as `r = (iv2 - v2) * stiffness`. - -#### Wind - -In order to simulate wind, you are at liberty to create any wind function you want! In order to have something interesting, -you can make the function depend on the position of `v0` and a function that changes with time. Consider using some combination -of sine or cosine functions. - -Your wind function will determine a wind direction that is affecting the blade, but it is also worth noting that wind has a larger impact on -grass blades whose forward directions are parallel to the wind direction. The paper describes this as a "wind alignment" term. We won't go -over the exact math here, but use the paper as a reference when implementing this. It does a great job of explaining this! - -Once you have a wind direction and a wind alignment term, your total wind force (`w`) will be `windDirection * windAlignment`. - -#### Total force - -We can then determine a translation for `v2` based on the forces as `tv2 = (gravity + recovery + wind) * deltaTime`. However, we can't simply -apply this translation and expect the simulation to be robust. Our forces might push `v2` under the ground! Similarly, moving `v2` but leaving -`v1` in the same position will cause our grass blade to change length, which doesn't make sense. - -Read section 5.2 of the paper in order to learn how to determine the corrected final positions for `v1` and `v2`. - -### Culling tests - -Although we need to simulate forces on every grass blade at every frame, there are many blades that we won't need to render -due to a variety of reasons. Here are some heuristics we can use to cull blades that won't contribute positively to a given frame. - -#### Orientation culling - -Consider the scenario in which the front face direction of the grass blade is perpendicular to the view vector. Since our grass blades -won't have width, we will end up trying to render parts of the grass that are actually smaller than the size of a pixel. This could -lead to aliasing artifacts. - -In order to remedy this, we can cull these blades! Simply do a dot product test to see if the view vector and front face direction of -the blade are perpendicular. The paper uses a threshold value of `0.9` to cull, but feel free to use what you think looks best. - -#### View-frustum culling - -We also want to cull blades that are outside of the view-frustum, considering they won't show up in the frame anyway. To determine if -a grass blade is in the view-frustum, we want to compare the visibility of three points: `v0, v2, and m`, where `m = (1/4)v0 * (1/2)v1 * (1/4)v2`. -Notice that we aren't using `v1` for the visibility test. This is because the `v1` is a Bezier guide that doesn't represent a position on the grass blade. -We instead use `m` to approximate the midpoint of our Bezier curve. - -If all three points are outside of the view-frustum, we will cull the grass blade. The paper uses a tolerance value for this test so that we are culling -blades a little more conservatively. This can help with cases in which the Bezier curve is technically not visible, but we might be able to see the blade -if we consider its width. - -#### Distance culling - -Similarly to orientation culling, we can end up with grass blades that at large distances are smaller than the size of a pixel. This could lead to additional -artifacts in our renders. In this case, we can cull grass blades as a function of their distance from the camera. - -You are free to define two parameters here. -* A max distance afterwhich all grass blades will be culled. -* A number of buckets to place grass blades between the camera and max distance into. - -Define a function such that the grass blades in the bucket closest to the camera are kept while an increasing number of grass blades -are culled with each farther bucket. - -#### Occlusion culling (extra credit) - -This type of culling only makes sense if our scene has additional objects aside from the plane and the grass blades. We want to cull grass blades that -are occluded by other geometry. Think about how you can use a depth map to accomplish this! - -### Tessellating Bezier curves into grass blades - -In this project, you should pass in each Bezier curve as a single patch to be processed by your grass graphics pipeline. You will tessellate this patch into -a quad with a shape of your choosing (as long as it looks sufficiently like grass of course). The paper has some examples of grass shapes you can use as inspiration. - -In the tessellation control shader, specify the amount of tessellation you want to occur. Remember that you need to provide enough detail to create the curvature of a grass blade. - -The generated vertices will be passed to the tessellation evaluation shader, where you will place the vertices in world space, respecting the width, height, and orientation information -of each blade. Once you have determined the world space position of each vector, make sure to set the output `gl_Position` in clip space! - -** Extra Credit**: Tessellate to varying levels of detail as a function of how far the grass blade is from the camera. For example, if the blade is very far, only generate four vertices in the tessellation control shader. - -To build more intuition on how tessellation works, I highly recommend playing with the [helloTessellation sample](https://github.com/CIS565-Fall-2018/Vulkan-Samples/tree/master/samples/5_helloTessellation) -and reading this [tutorial on tessellation](http://in2gpu.com/2014/07/12/tessellation-tutorial-opengl-4-3/). - -## Resources - -### Links - -The following resources may be useful for this project. +## References * [Responsive Real-Time Grass Grass Rendering for General 3D Scenes](https://www.cg.tuwien.ac.at/research/publications/2017/JAHRMANN-2017-RRTG/JAHRMANN-2017-RRTG-draft.pdf) -* [CIS565 Vulkan samples](https://github.com/CIS565-Fall-2018/Vulkan-Samples) * [Official Vulkan documentation](https://www.khronos.org/registry/vulkan/) * [Vulkan tutorial](https://vulkan-tutorial.com/) -* [RenderDoc blog on Vulkan](https://renderdoc.org/vulkan-in-30-minutes.html) * [Tessellation tutorial](http://in2gpu.com/2014/07/12/tessellation-tutorial-opengl-4-3/) - -## Third-Party Code Policy - -* Use of any third-party code must be approved by asking on our Google Group. -* If it is approved, all students are welcome to use it. Generally, we approve - use of third-party code that is not a core part of the project. For example, - for the path tracer, we would approve using a third-party library for loading - models, but would not approve copying and pasting a CUDA function for doing - refraction. -* Third-party code **MUST** be credited in README.md. -* Using third-party code without its approval, including using another - student's code, is an academic integrity violation, and will, at minimum, - result in you receiving an F for the semester. - - -## README - -* A brief description of the project and the specific features you implemented. -* GIFs of your project in its different stages with the different features being added incrementally. -* A performance analysis (described below). - -### Performance Analysis - -The performance analysis is where you will investigate how... -* Your renderer handles varying numbers of grass blades -* The improvement you get by culling using each of the three culling tests - -## Submit - -If you have modified any of the `CMakeLists.txt` files at all (aside from the -list of `SOURCE_FILES`), mentions it explicity. -Beware of any build issues discussed on the Google Group. - -Open a GitHub pull request so that we can see that you have finished. -The title should be "Project 6: YOUR NAME". -The template of the comment section of your pull request is attached below, you can do some copy and paste: - -* [Repo Link](https://link-to-your-repo) -* (Briefly) Mentions features that you've completed. Especially those bells and whistles you want to highlight - * Feature 0 - * Feature 1 - * ... -* Feedback on the project itself, if any. diff --git a/bin/Debug/vulkan_grass_rendering.exe b/bin/Debug/vulkan_grass_rendering.exe new file mode 100644 index 0000000..9ceeec0 Binary files /dev/null and b/bin/Debug/vulkan_grass_rendering.exe differ diff --git a/bin/Debug/vulkan_grass_rendering.ilk b/bin/Debug/vulkan_grass_rendering.ilk new file mode 100644 index 0000000..96a8891 Binary files /dev/null and b/bin/Debug/vulkan_grass_rendering.ilk differ diff --git a/bin/Debug/vulkan_grass_rendering.pdb b/bin/Debug/vulkan_grass_rendering.pdb new file mode 100644 index 0000000..7e702d6 Binary files /dev/null and b/bin/Debug/vulkan_grass_rendering.pdb differ diff --git a/bin/Release/vulkan_grass_rendering.exe b/bin/Release/vulkan_grass_rendering.exe new file mode 100644 index 0000000..4b31287 Binary files /dev/null and b/bin/Release/vulkan_grass_rendering.exe differ diff --git a/img/g1.gif b/img/g1.gif new file mode 100644 index 0000000..f859f79 Binary files /dev/null and b/img/g1.gif differ diff --git a/img/g11.png b/img/g11.png new file mode 100644 index 0000000..3738416 Binary files /dev/null and b/img/g11.png differ diff --git a/img/g2.gif b/img/g2.gif new file mode 100644 index 0000000..d8e3b39 Binary files /dev/null and b/img/g2.gif differ diff --git a/img/g22.png b/img/g22.png new file mode 100644 index 0000000..9561d88 Binary files /dev/null and b/img/g22.png differ diff --git a/img/logo.png b/img/logo.png new file mode 100644 index 0000000..a2e7f9e Binary files /dev/null and b/img/logo.png differ diff --git a/img/performance1.png b/img/performance1.png new file mode 100644 index 0000000..8825cbc Binary files /dev/null and b/img/performance1.png differ diff --git a/img/performance2.png b/img/performance2.png new file mode 100644 index 0000000..ec4af08 Binary files /dev/null and b/img/performance2.png differ diff --git a/img/tese1.png b/img/tese1.png new file mode 100644 index 0000000..2af4fce Binary files /dev/null and b/img/tese1.png differ diff --git a/img/tese2.png b/img/tese2.png new file mode 100644 index 0000000..736dfc5 Binary files /dev/null and b/img/tese2.png differ diff --git a/src/Blades.h b/src/Blades.h index 9bd1eed..bab7736 100644 --- a/src/Blades.h +++ b/src/Blades.h @@ -4,13 +4,13 @@ #include #include "Model.h" -constexpr static unsigned int NUM_BLADES = 1 << 13; +constexpr static unsigned int NUM_BLADES = 1 << 15; constexpr static float MIN_HEIGHT = 1.3f; constexpr static float MAX_HEIGHT = 2.5f; constexpr static float MIN_WIDTH = 0.1f; -constexpr static float MAX_WIDTH = 0.14f; +constexpr static float MAX_WIDTH = 0.30f; constexpr static float MIN_BEND = 7.0f; -constexpr static float MAX_BEND = 13.0f; +constexpr static float MAX_BEND = 11.0f; struct Blade { // Position and direction diff --git a/src/Renderer.cpp b/src/Renderer.cpp index b445d04..c9b4280 100644 --- a/src/Renderer.cpp +++ b/src/Renderer.cpp @@ -198,6 +198,50 @@ 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 + + //The compute shader will perform culling: + //each thread read a blade, then determine whether it's culled or not, then write into a new array of blades + //given this, where would be three layout descriptors: + + //the descriptor of input blades + VkDescriptorSetLayoutBinding inputBladesLayoutBinding = {}; + inputBladesLayoutBinding.binding = 0; + inputBladesLayoutBinding.descriptorType = VK_DESCRIPTOR_TYPE_STORAGE_BUFFER; + inputBladesLayoutBinding.descriptorCount = 1; + inputBladesLayoutBinding.stageFlags = VK_SHADER_STAGE_COMPUTE_BIT; + inputBladesLayoutBinding.pImmutableSamplers = nullptr; + + //the descriptor of culled blades + 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; + + //the descriptor of number of blades + VkDescriptorSetLayoutBinding numAllBladesLayoutBinding = {}; + numAllBladesLayoutBinding.binding = 2; + numAllBladesLayoutBinding.descriptorType = VK_DESCRIPTOR_TYPE_STORAGE_BUFFER; + numAllBladesLayoutBinding.descriptorCount = 1; + numAllBladesLayoutBinding.stageFlags = VK_SHADER_STAGE_COMPUTE_BIT; + numAllBladesLayoutBinding.pImmutableSamplers = nullptr; + + //set of descriptors + std::vectorbindings = { inputBladesLayoutBinding, culledBladesLayoutBinding,numAllBladesLayoutBinding }; + + //create layout + VkDescriptorSetLayoutCreateInfo layoutInfo = {}; + layoutInfo.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO; + //pNext should be nullptr, but the other descriptor creating functions didn't set it explicitly, is that ok? + layoutInfo.pNext = nullptr; + layoutInfo.bindingCount = static_cast(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::CreateDescriptorPool() { @@ -216,7 +260,9 @@ void Renderer::CreateDescriptorPool() { { VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER , 1 }, // TODO: Add any additional types and counts of descriptors you will need to allocate - }; + // the number of blades, as input to compute shader (compute) + { VK_DESCRIPTOR_TYPE_STORAGE_BUFFER , static_cast(scene->GetBlades().size() * 3)}, + }; VkDescriptorPoolCreateInfo poolInfo = {}; poolInfo.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO; @@ -320,6 +366,48 @@ 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 + + //resize the grass descriptor vector + grassDescriptorSets.resize(scene->GetBlades().size()); + + // Describe the desciptor set + //we don't have a function to create new descriptor set layout for grass + //because grass is essentially also model, so we use model's descriptor set layout + VkDescriptorSetLayout layouts[] = { modelDescriptorSetLayout }; + VkDescriptorSetAllocateInfo allocInfo = {}; + allocInfo.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO; + allocInfo.descriptorPool = descriptorPool; + allocInfo.descriptorSetCount = static_cast(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 descriptorWrites(grassDescriptorSets.size()); + + for (uint32_t i = 0; i < scene->GetBlades().size(); ++i) { + VkDescriptorBufferInfo grassBufferInfo = {}; + grassBufferInfo.buffer = scene->GetModels()[i]->GetModelBuffer(); + grassBufferInfo.offset = 0; + grassBufferInfo.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 = &grassBufferInfo; + descriptorWrites[i].pImageInfo = nullptr; + descriptorWrites[i].pTexelBufferView = nullptr; + + } + + // Update descriptor sets + vkUpdateDescriptorSets(logicalDevice, static_cast(descriptorWrites.size()), descriptorWrites.data(), 0, nullptr); + } void Renderer::CreateTimeDescriptorSet() { @@ -360,6 +448,79 @@ 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 descriptor set + VkDescriptorSetLayout layouts[] = { computeDescriptorSetLayout }; + VkDescriptorSetAllocateInfo allocInfo = {}; + allocInfo.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO; + allocInfo.descriptorPool = descriptorPool; + allocInfo.descriptorSetCount = static_cast(computeDescriptorSets.size()); + allocInfo.pSetLayouts = layouts; + + //Allocate descriptor sets + if (vkAllocateDescriptorSets(logicalDevice, &allocInfo, computeDescriptorSets.data()) != VK_SUCCESS) { + throw std::runtime_error("Failed = allocate descriptor set"); + } + + //configure for each descriptor + std::vector descriptorWrites(3 * computeDescriptorSets.size()); + //for each blade, write into actuall blade buffers + uint32_t bladesSize = scene->GetBlades().size(); + for (uint32_t i = 0; i < bladesSize; i++) { + //input blades buffer + VkDescriptorBufferInfo inputBladesBufferInfo = {}; + inputBladesBufferInfo.buffer = scene->GetBlades()[i]->GetBladesBuffer(); + inputBladesBufferInfo.offset = 0; + inputBladesBufferInfo.range = NUM_BLADES * sizeof(Blade); + + //visible (or culled) blades buffer + VkDescriptorBufferInfo culledBladesBufferInfo = {}; + culledBladesBufferInfo.buffer = scene->GetBlades()[i]->GetCulledBladesBuffer(); + culledBladesBufferInfo.offset = 0; + culledBladesBufferInfo.range = NUM_BLADES * sizeof(Blade); + + //num of all blades buffer + VkDescriptorBufferInfo numAllBladesBufferInfo = {}; + numAllBladesBufferInfo.buffer = scene->GetBlades()[i]->GetNumBladesBuffer(); + numAllBladesBufferInfo.offset = 0; + numAllBladesBufferInfo.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].dstArrayElement = 0; + descriptorWrites[3 * i + 0].descriptorType = VK_DESCRIPTOR_TYPE_STORAGE_BUFFER; + descriptorWrites[3 * i + 0].descriptorCount = 1; + descriptorWrites[3 * i + 0].pBufferInfo = &inputBladesBufferInfo; + 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].dstArrayElement = 0; + 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].dstArrayElement = 0; + descriptorWrites[3 * i + 2].descriptorType = VK_DESCRIPTOR_TYPE_STORAGE_BUFFER; + descriptorWrites[3 * i + 2].descriptorCount = 1; + descriptorWrites[3 * i + 2].pBufferInfo = &numAllBladesBufferInfo; + descriptorWrites[3 * i + 2].pImageInfo = nullptr; + descriptorWrites[3 * i + 2].pTexelBufferView = nullptr; + + }//end for loop + + // Update descriptor sets + vkUpdateDescriptorSets(logicalDevice, static_cast(descriptorWrites.size()), descriptorWrites.data(), 0, nullptr); } void Renderer::CreateGraphicsPipeline() { @@ -717,7 +878,7 @@ void Renderer::CreateComputePipeline() { computeShaderStageInfo.pName = "main"; // TODO: Add the compute dsecriptor set layout you create to this list - std::vector descriptorSetLayouts = { cameraDescriptorSetLayout, timeDescriptorSetLayout }; + std::vector descriptorSetLayouts = { cameraDescriptorSetLayout, timeDescriptorSetLayout, computeDescriptorSetLayout }; // Create pipeline layout VkPipelineLayoutCreateInfo pipelineLayoutInfo = {}; @@ -884,6 +1045,14 @@ 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 i = 0; i < scene->GetBlades().size(); ++i) { + //Bind descriptor sets for compute + vkCmdBindDescriptorSets(computeCommandBuffer, VK_PIPELINE_BIND_POINT_COMPUTE, computePipelineLayout, 2, 1, &computeDescriptorSets[i], 0, nullptr); + + //compute kernel launch + vkCmdDispatch(computeCommandBuffer, (int)ceil(NUM_BLADES / WORKGROUP_SIZE), 1, 1); + + } // ~ End recording ~ if (vkEndCommandBuffer(computeCommandBuffer) != VK_SUCCESS) { @@ -976,13 +1145,15 @@ 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 @@ -1057,6 +1228,7 @@ Renderer::~Renderer() { vkDestroyDescriptorSetLayout(logicalDevice, cameraDescriptorSetLayout, nullptr); vkDestroyDescriptorSetLayout(logicalDevice, modelDescriptorSetLayout, nullptr); vkDestroyDescriptorSetLayout(logicalDevice, timeDescriptorSetLayout, nullptr); + vkDestroyDescriptorSetLayout(logicalDevice, computeDescriptorSetLayout, nullptr); vkDestroyDescriptorPool(logicalDevice, descriptorPool, nullptr); diff --git a/src/Renderer.h b/src/Renderer.h index 95e025f..4d1ad4c 100644 --- a/src/Renderer.h +++ b/src/Renderer.h @@ -56,12 +56,18 @@ class Renderer { VkDescriptorSetLayout cameraDescriptorSetLayout; VkDescriptorSetLayout modelDescriptorSetLayout; VkDescriptorSetLayout timeDescriptorSetLayout; + //add: setlayout object for compute shader + VkDescriptorSetLayout computeDescriptorSetLayout; VkDescriptorPool descriptorPool; VkDescriptorSet cameraDescriptorSet; std::vector modelDescriptorSets; VkDescriptorSet timeDescriptorSet; + //add: descriptor sets object for compute shader + std::vector computeDescriptorSets; + //add: descriptor sets object for grass descriptors + std::vector grassDescriptorSets; VkPipelineLayout graphicsPipelineLayout; VkPipelineLayout grassPipelineLayout; diff --git a/src/main.cpp b/src/main.cpp index 8bf822b..be1403d 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -67,7 +67,7 @@ namespace { int main() { static constexpr char* applicationName = "Vulkan Grass Rendering"; - InitializeWindow(640, 480, applicationName); + InitializeWindow(1280, 960, applicationName); unsigned int glfwExtensionCount = 0; const char** glfwExtensions = glfwGetRequiredInstanceExtensions(&glfwExtensionCount); @@ -116,7 +116,7 @@ int main() { grassImageMemory ); - float planeDim = 15.f; + float planeDim = 25.f; float halfWidth = planeDim * 0.5f; Model* plane = new Model(device, transferCommandPool, { diff --git a/src/shaders/compute.comp b/src/shaders/compute.comp index 0fd0224..223772d 100644 --- a/src/shaders/compute.comp +++ b/src/shaders/compute.comp @@ -26,15 +26,25 @@ struct Blade { // 2. Write out the culled blades // 3. Write the total number of blades remaining +//in +layout(set = 2, binding = 0) buffer InputBlades { + Blade inputBlades[]; +}; + +//out +layout(set = 2, binding = 1) buffer CulledBlades { + Blade culledBlades[]; +}; + // The project is using vkCmdDrawIndirect to use a buffer as the arguments for a draw call // This is sort of an advanced feature so we've showed you what this buffer should look like // -// layout(set = ???, binding = ???) buffer NumBlades { -// uint vertexCount; // Write the number of blades remaining here -// uint instanceCount; // = 1 -// uint firstVertex; // = 0 -// uint firstInstance; // = 0 -// } numBlades; +layout(set = 2, binding = 2) buffer NumBlades { + uint vertexCount; // Write the number of blades remaining here + uint instanceCount; // = 1 + int firstVertex; // = 0 + uint firstInstance; // = 0 +} numBlades; bool inBounds(float value, float bounds) { return (value >= -bounds) && (value <= bounds); @@ -43,14 +53,143 @@ bool inBounds(float value, float bounds) { void main() { // Reset the number of blades to 0 if (gl_GlobalInvocationID.x == 0) { - // numBlades.vertexCount = 0; + numBlades.vertexCount = 0; } + uint index = gl_GlobalInvocationID.x; + barrier(); // Wait till all threads reach this point // TODO: Apply forces on every blade and update the vertices in the buffer + //get the current blade + Blade currBlade = inputBlades[index]; + + //read infomation + vec3 v0Pos = currBlade.v0.xyz; + float dir_angle = currBlade.v0.w; + float height = currBlade.v1.w; + vec3 v2Pos = currBlade.v2.xyz; + vec3 up_Dir = currBlade.up.xyz; + float stiffness = currBlade.up.w; + + //Compute gravity + float g_accel = 9.8; + vec3 g_dir = -normalize(up_Dir); + vec3 gE = g_accel * g_dir; + + vec3 dir_Vec = vec3(sin(dir_angle), 0.0, cos(dir_angle)); + dir_Vec = normalize(dir_Vec); + vec3 gF = -0.25 * length(gE) * dir_Vec; + + vec3 g = gE + gF; + + //Compute recovery force + vec3 v2Pos_Initial = v0Pos + up_Dir * height; + vec3 recov_F = stiffness * (v2Pos_Initial - v2Pos); + + //Compute wind force + float windLevel = 6.0; + vec3 wind_Dir = normalize(vec3(1.0, 0.0, -2.0)); + vec3 wind_Wave = windLevel * ( 0.46 * cos (0.7 * 3.1415926) + sin( 0.3 * v0Pos.x + totalTime / 0.9) + 1.77)* wind_Dir; + + vec3 blade_Dir = v2Pos - v0Pos; + float alignment_up = 1.0 - abs(dot(normalize(wind_Wave), normalize(blade_Dir))); + float alignment_hori = dot(blade_Dir, up_Dir) / height; + + vec3 wind_F = alignment_up * alignment_hori * wind_Wave; + + //apply force to change v2's position + v2Pos += deltaTime * (g + recov_F + wind_F); + + //validation of new v2's position + float under_ground = min(dot(up_Dir, v2Pos - v0Pos), 0.0); + v2Pos -= under_ground * up_Dir; + + //Then get v1's position from v0 & v2 + blade_Dir = v2Pos - v0Pos; + float l_proj = length(blade_Dir - dot(blade_Dir, up_Dir) * up_Dir); + float l_projH = l_proj / height; + vec3 v1Pos = v0Pos + height * max(1.0 - l_projH, 0.05 * max(l_projH, 1.0)) * up_Dir; + + //Positon corrections + float L0 = distance(v2Pos, v0Pos); + float L1 = distance(v2Pos, v1Pos) + distance(v1Pos, v0Pos); + float degree = 3.0; + + float L = (2.0 * L0 + (degree - 1.0) * L1) / (degree + 1.0); + float r = height/L; + + vec3 v1Pos_corrected = v0Pos + r * (v1Pos - v0Pos); + vec3 v2Pos_corrected = v1Pos + r * (v2Pos - v1Pos); + + //write new v1 & v2 positions into current blade + currBlade.v1.xyz = v1Pos; + currBlade.v2.xyz = v2Pos; + inputBlades[index] = currBlade; + // TODO: Cull blades that are too far away or not in the camera frustum and write them // to the culled blades buffer // Note: to do this, you will need to use an atomic operation to read and update numBlades.vertexCount // You want to write the visible blades to the buffer without write conflicts between threads + + //1: orientation culling + bool culledByOrientation = false; + float orientationCullingThreshold = 0.01f; + //read from view matrix, construct view direction vector + vec3 view_Dir; + view_Dir.x = camera.view[0][0] + camera.view[0][1] + camera.view[0][2]; + view_Dir.y = 0.0; + view_Dir.z = camera.view[2][0] + camera.view[2][1] + camera.view[2][2]; + view_Dir = normalize(view_Dir); + //check dot product again threshold + if(abs(dot(view_Dir, dir_Vec)) < orientationCullingThreshold){ + culledByOrientation = true; + } + + //2. view frustum culling + mat4 viewProjM = camera.proj * camera.view; + vec4 test_v0_vec4 = vec4(currBlade.v0.xyz, 1.0); + vec4 test_middle_vec4 = vec4(0.25 * currBlade.v0.xyz + 0.5 * currBlade.v1.xyz + 0.25 * currBlade.v2.xyz, 1.0); + vec4 test_v2_vec4 = vec4(currBlade.v2.xyz, 1.0); + + test_v0_vec4 = viewProjM * test_v0_vec4; + test_v0_vec4 /= test_v0_vec4.w; + + float testThreshold = 0.3; + + float h = test_v0_vec4.w + testThreshold; + bool v0InFrustum = (test_v0_vec4.x >= -h) && (test_v0_vec4.x <= h) + &&(test_v0_vec4.y >= -h) && (test_v0_vec4.y <= h) + &&(test_v0_vec4.z >= -h) && (test_v0_vec4.z <= h); + + h = test_middle_vec4.w + testThreshold; + bool middleInFrustum = (test_middle_vec4.x >= -h) && (test_middle_vec4.x <= h) + &&(test_middle_vec4.y >= -h) && (test_middle_vec4.y <= h) + &&(test_middle_vec4.z >= -h) && (test_middle_vec4.z <= h); + + h = test_v2_vec4.w + testThreshold; + bool v2InFrustum = (test_v2_vec4.x >= -h) && (test_v2_vec4.x <= h) + &&(test_v2_vec4.y >= -h) && (test_v2_vec4.y <= h) + &&(test_v2_vec4.z >= -h) && (test_v2_vec4.z <= h); + + bool culledByFrustum = (!v0InFrustum) && (!middleInFrustum) && (!v2InFrustum); + + //3: distance culling + float cullingDistance = 100.0; + + vec3 cameraPos = vec3(camera.view[3][0],camera.view[3][1],camera.view[3][2]); + cameraPos = -cameraPos; + + vec3 camera2v0 = v0Pos - cameraPos; + float d_proj = length(camera2v0 - dot(camera2v0, up_Dir) * up_Dir); + + uint numDistanceCullingBuckets = 5; + uint bucketNO = index % numDistanceCullingBuckets; + float roundedBucketNo = floor(numDistanceCullingBuckets * (1.0 - d_proj / cullingDistance)); + + bool culledByDistance = !(bucketNO <= uint(roundedBucketNo)); + + if(!culledByOrientation && !culledByFrustum && !culledByDistance){ + culledBlades[atomicAdd(numBlades.vertexCount, 1)] = currBlade; + } } diff --git a/src/shaders/grass.frag b/src/shaders/grass.frag index c7df157..7421d51 100644 --- a/src/shaders/grass.frag +++ b/src/shaders/grass.frag @@ -8,10 +8,27 @@ layout(set = 0, binding = 0) uniform CameraBufferObject { // TODO: Declare fragment shader inputs +layout(location = 0) in vec4 pos; +layout(location = 1) in vec3 nor; +layout(location = 2) in vec3 forward; +layout(location = 3) in vec2 uv; + + layout(location = 0) out vec4 outColor; void main() { // TODO: Compute fragment color - outColor = vec4(1.0); + vec3 topCol = vec3(0.50, 0.99, 0.43); + vec3 botCol = vec3(0.60, 0.99, 0.60); + //interpolate between bottom color and top color + vec3 inter_Col = mix(botCol, topCol, uv.y); + + //sun direction + vec3 lightDir = vec3(-4.0, 9.0, 3.0); + lightDir = normalize(lightDir); + float lambertian = dot(nor, lightDir); + lambertian = clamp(lambertian, 0.0,1.0) + 0.40; + + outColor = vec4(inter_Col * lambertian, 1.0); } diff --git a/src/shaders/grass.tesc b/src/shaders/grass.tesc index f9ffd07..ad4bed8 100644 --- a/src/shaders/grass.tesc +++ b/src/shaders/grass.tesc @@ -10,17 +10,56 @@ layout(set = 0, binding = 0) uniform CameraBufferObject { // TODO: Declare tessellation control shader inputs and outputs +//inputs are from grass.vert +layout (location = 0) in vec4 tesc_v1[]; +layout (location = 1) in vec4 tesc_v2[]; +layout (location = 2) in vec4 tesc_up[]; +layout (location = 3) in vec4 tesc_forward[]; + +//output to tessellation.evaluation stage + +layout (location = 0) patch out vec4 tese_v1; +layout (location = 1) patch out vec4 tese_v2; +layout (location = 2) patch out vec4 tese_up; +layout (location = 3) patch out vec4 tese_forward; + + void main() { // Don't move the origin location of the patch gl_out[gl_InvocationID].gl_Position = gl_in[gl_InvocationID].gl_Position; // TODO: Write any shader outputs + //test: pass thru + tese_v1 = tesc_v1[0]; + tese_v2 = tesc_v2[0]; + tese_up = tesc_up[0]; + tese_forward = tesc_forward[0]; + // TODO: Set level of tesselation - // gl_TessLevelInner[0] = ??? - // gl_TessLevelInner[1] = ??? - // gl_TessLevelOuter[0] = ??? - // gl_TessLevelOuter[1] = ??? - // gl_TessLevelOuter[2] = ??? - // gl_TessLevelOuter[3] = ??? + + //tessellation on different levels depending on distance: + //need to get the distance in projection space + + vec4 posWorld = gl_in[gl_InvocationID].gl_Position; + posWorld.w = 1.0; + //projection space + posWorld = camera.proj * camera.view * posWorld; + //projection division + posWorld /= posWorld.w; + //get depth in normalized z-space + float depth = clamp(-posWorld.z, 0.0, 1.0); + + float tessLevelmin = 3.0; + float tessLevelmax = 10.0; + + float tessLevel = mix(tessLevelmax, tessLevelmin, 0.25 * (depth * 5.0)); + + gl_TessLevelInner[0] = 1.0; + gl_TessLevelInner[1] = tessLevel; + + gl_TessLevelOuter[0] = tessLevel; + gl_TessLevelOuter[1] = 1.0; + gl_TessLevelOuter[2] = tessLevel; + gl_TessLevelOuter[3] = 1.0; } diff --git a/src/shaders/grass.tese b/src/shaders/grass.tese index 751fff6..c7bd0dd 100644 --- a/src/shaders/grass.tese +++ b/src/shaders/grass.tese @@ -10,9 +10,57 @@ layout(set = 0, binding = 0) uniform CameraBufferObject { // TODO: Declare tessellation evaluation shader inputs and outputs +//inputs are from tessellation.control shader +layout(location = 0) patch in vec4 tese_v1; +layout(location = 1) patch in vec4 tese_v2; +layout(location = 2) patch in vec4 tese_up; +layout(location = 3) patch in vec4 tese_forward; + +//output to fragment shader for shading +layout(location = 0) out vec4 pos; +layout(location = 1) out vec3 nor; +layout(location = 2) out vec3 forward; +layout(location = 3) out vec2 uv; + + void main() { float u = gl_TessCoord.x; float v = gl_TessCoord.y; // TODO: Use u and v to parameterize along the grass blade and output positions for each vertex of the grass blade + //get bezier curve control points + vec3 p1 = gl_in[0].gl_Position.xyz; + vec3 p2 = tese_v1.xyz; + vec3 p3 = tese_v2.xyz; + + //use casteljau alg to calculate position on curve + vec3 p11 = p1 + v * (p2 - p1); + vec3 p21 = p2 + v * (p3 - p2); + vec3 p = p11 + v * (p21 - p11); + + //expand on width direction + vec3 width_dir = cross(tese_up.xyz, tese_forward.xyz); + vec3 width_offset = width_dir * tese_v2.w * 0.5; + vec3 p_left = p - width_offset; + vec3 p_right = p + width_offset; + + //interpolate on this left-right line + //float parameter = u + 0.5 * v - u * v; + float parameter = u - u * v * v; + + pos.xyz = (1.0-parameter) * p_left + parameter * p_right; + pos = camera.proj * camera.view * vec4(pos.xyz, 1.0); + + //compose uv + uv = vec2(u,v); + + //calculate new normal + vec3 grow_dir = normalize(p21 - p11); + nor = normalize(cross(width_dir, grow_dir)); + + //new forward (just pass thru) + forward = tese_forward.xyz; + + gl_Position = pos; + } diff --git a/src/shaders/grass.vert b/src/shaders/grass.vert index db9dfe9..7b2ca74 100644 --- a/src/shaders/grass.vert +++ b/src/shaders/grass.vert @@ -7,6 +7,15 @@ layout(set = 1, binding = 0) uniform ModelBufferObject { }; // TODO: Declare vertex shader inputs and outputs +layout (location = 0) in vec4 v0; +layout (location = 1) in vec4 v1; +layout (location = 2) in vec4 v2; +layout (location = 3) in vec4 up; + +layout (location = 0) out vec4 tesc_v1; +layout (location = 1) out vec4 tesc_v2; +layout (location = 2) out vec4 tesc_up; +layout (location = 3) out vec4 tesc_forward; out gl_PerVertex { vec4 gl_Position; @@ -14,4 +23,18 @@ out gl_PerVertex { void main() { // TODO: Write gl_Position and any other shader outputs + tesc_v1 = model * vec4(v1.xyz, 1.0); + tesc_v1.w = v1.w; + + tesc_v2 = model * vec4(v2.xyz, 1.0); + tesc_v2.w = v2.w; + + tesc_up = vec4(normalize(up.xyz), 0.0); + + float dir = v0.w; + vec3 faceTo = vec3(sin(dir), 0.0, cos(dir)); + faceTo = -normalize(faceTo); + tesc_forward = vec4(faceTo,0.0); + + gl_Position = model * vec4(v0.xyz, 1.0); }