A Vulkan rendering engine that I've taken upon building in order to solidify my knowledge of Vulkan and graphics programming as a whole by implementing interesting graphics features and applications.
The engine runs on Vulkan 1.3 using VK_KHR_synchronization2 and the code is written for the C++20 standard.
vulkr_demo.mp4
- Rendering GLTF (.gltf and .glb) or OBJ asset formats in real-time
- Choosing between forward rendering, deferred rendering and raytracing (VK_KHR_ray_tracing) as rendering methods (configurable at runtime)
- Triple buffering with two sets of frame resources
- Instanced object rendering
- Multiple global light sources that can be set as a directional (infinite) or point light with customizable intensity and position values
- Temporal Anti-Aliasing for static and dynamic scenes (rasterization only so far); implemented using techniques mentioned in the "A Survey of Temporal Antialising Techniques" white paper and Ziyad Barakat's TAA Blog Post
- A free flight camera with similar controls to blender
- A imgui debug window that provides access to altering the camera and light settings
- Shadows (works with ray_tracing only so far)
- A particle system implemented using compute shaders for the position and velocity calculations
vulkr-particle-system.mp4
- A 2D fluid simulator that implements velocity & density advection, gaussian splat on mouse click + drag, and a projection steps that solve for the poisson pressure equation and subtracts the gradient of the pressure from the velocity field; implemented using the techniques mentioned in Mark Harris' "Fluid Dynamics Simulation on the GPU" GPU Gems article
2d_fluid_sim.mp4
This project requires the latest Vulkan v1.3 SDK and the latest CMake installed (v3.10 or above) installed on the host's computer. All other third-party dependencies should be imported when cloning the project with the --recurse-submodules option. I developed Vulkr running Windows 10, x64 using Visual Studio 2022 and as such, an not be expected to work on Linux or MacOS. However, all third-party libraries used are cross platform and OS platform specific components like the windowing system could be supported in the future.
The easiest way to run the project is to load it using Visual Studio 2022 and building the project. You could then select any application executable file (vulkr_app.exe or fluid_simulation.exe) as a startup item using the x64-Release configuration and run the project. The build files can be found under build/x64-Release if desired. Alternatively, running the following CMAKE commands from the root folder level will build the project.
cmake -S . -B build
cmake --build build
For optimal performance, ensure that the VULKR_DEBUG flag is not defined in vulkan_common.h. Building in release mode should disable this flag. If you wish to debug the engine using RenderDoc, be sure to enable the RENDERDOC_DEBUG flag; also located in vulkan_common.h so that unsupported extensions like VK_KHR_ray_tracing are disabled to prevent RenderDoc from complaining about them. NSight Systems and NSight Graphics should work without that flag.
Vulkr
|-- apps # All applcation classes are located here
| |-- Vulkr # Main Vulkr Application
| |-- Fluid Simulation # 2D Fluid Simulation Application
|-- assets
| |-- glTF models # All glTF files (.gltf & .glb)
| |-- OBJ model # All OBJ related files (.obj and .mtl)
| |-- textures # Textures for both gltf and obj models (note that some glb files embed texture information)
|-- shaders
| |-- fluid_simulation # ALl shader related to the 2D fluid simulation app
| |-- particle_system # Shaders required to calculate and render particle positions
| |-- rasterization # Shaders for rasterization techniques eg. forward, deferred rendering
| |-- ray_tracing # Ray tracing related shaders
| |-- post_processing # Shaders for all post processing techniques eg. TAA
| |-- common.glsl # Contains common structs that need to be synced across CPU/GPU and are used in various shaders
| |-- random.glsl # RNG helpers
| |-- build.bat # The script to compile shaders into spirv. If you don't execute this after any shader changes, the spirv WILL NOT change
|-- src
| |-- common # Common utils and helpers are located here
| |-- core # Core Vulkan API classes
| |-- platform # Everything related to setting up the platform (eg. windowing system, processing key and mouse inputs)
| |-- rendering # All other rendering related classes
|-- third_party # All external dependencies; details on each library mentioned in the dependencies section belowMy goal with Vulkr is to create a sandbox engine where I could spend most of my time implement interesting graphics related features while focusing on the rendering specific code to accomplish the task correctly and in a peformant manner. As such, I've relied on a variety to amazing third party libraries to help me do all of the other things that are required for making a rendering engine but are not related to those core goals mentioned before.
As mentioned before, there are two external dependencies that need to be installed separately by the user
Here are the rest of the external libraries used that are included as submodules on this project
- Vulkan Memory Allocator -> Memory allocation library for Vulkan
- GLFW -> Multi-platform general windowing system
- GLM -> Math library based on the GLSL sepcifications
- Dear ImGui -> Immediate mode graphics user interface; mainly used for debugging
- spdlog -> Fast/low-overhead logging library
- stb -> Single file public domain libraries; mainly used for image loading helpers
- tiny glTF -> Peformant glTF library
- tinyobjloader -> Performant OBJ loading library
- volk -> Meta-loader for Vulkan
A special thanks to Alexander Overvoorde's Vulkan Tutorial for providing a great introduction to Vulkan as a whole and providing the base knowledge required to get started on this project. Additionally, Sascha Willems' Vulkan Demos, Vulkan-glTF-PBR, Vulkan Samples provided by the Khronos Group and the Vulkan Ray Tracing Samples provided by NVIDIA have played an instrumental role into providing guidance into best practices, techniques and code samples for implementing various features using Vulkan. The discord and reddit communities on Vulkan and Graphics Programming have been very helpful with answering many of the questions that I've gotten along the way!
Much of the models and textures that I'm using are from KhronosGroup's glTF-Sample-Asset repository so please refer to the author credits and license agreements mentioned in that repository.