![Metal Pass
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Skybox in HDR
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[0]](https://image.slidesharecdn.com/siggvkfx-170816013619/75/vkFX-Effect-ive-approach-for-Vulkan-API-30-2048.jpg)
Uploaded byTristan Lorach
vkFX: Effect(ive) approach for Vulkan API
The document discusses 'vkfx', a tool designed to simplify the use of the Vulkan API, enabling developers to create complex graphics effects more efficiently. It covers its features, usage, and the evolution of graphics programming from older technologies to Vulkan, highlighting how vkfx facilitates shader management, effect integration, and scene manipulation. It also outlines the plan for its open-source release and future enhancements to the vkfx runtime and parser.
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vkFX: Effect(ive) approach for Vulkan API
- 1. vkFX: Effect(ive) approachfor Vulkan API Tristan Lorach tlorach@nvidia.com
- 2. Intent NVIDIA cares onencouraging new technologies like Vulkan help engineers adoption Give out tools, samples (Open-Source) Game Engine : baking Shaders and states CAD/DCC : loading at runtime Shader Effects Prototyping : experiment on shaders and visual effects Research : help using Vulkan API Learn : discover Vulkan Inspire : share concepts and idea from vkFx
- 3. What is ‘vkFx’? Coherent and readable Graphic API’s component Description Render-states Shaders (Snippets) Resources Maps to Vulkan API (you need to know Vulkan for next slides!) Simplifies Vulkan usage, while keeping its strength More Features for higher level of abstraction (Techniques and Passes) Available through Runtime library to load vkFX files at runtime Offline compiler Generating readable C++ ( ‘baking’ effects)
- 4. From CgFx tonow… ~2003 : Cg and first HLSL shading introduced Effects (CgFX and HLSLFx) 2014 : nvFx Open-source, as a layer on top of OpenGL and/or D3D But overall Interest of ‘Effect’ part was questionable : no pre-validation of Render-States + Shaders in OpenGL / D3D 2016: DX12 and Vulkan Pre-Validation Now a First Vulkan’s feature Could allow better implementation of ‘Effects’ 2017 : vkFx pre-release as Open-Source (soon this year) Check https://github.com/tlorach/vkFX (or contact me)
- 5. What can youdo with it ? … Pretty much everything that Vulkan API allows to do… complex scenes passes - complex materials and lighting
- 6. Techniques and Passes Effect file Shaderfunc’s Sampler-states Parameters Techniques Passes states Texture Samplers Textures (D3D) GPU … • Validate passes (builds shaders) • Execute Passes • Bind shaders, states & resources Compiler Application Scene Shaders Render states Resources Meshes Shaders Render states Resources
- 7. 1 Example : HDRRendering With Glow Render Skybox in HDR Render The Scene in HDR Down-scale the texture 2x, 4x Blur texture Horizontal Then Vertical Scene Effect 1 2 3 4 5 6 Material Tech.1 Metal Pass Material Tech.2 Plastic pass Scene Graph More… RGBA32F Texture (HDR) Compositing: tone-mapping And radial Blur 7 RGBA 32F Texture Backbuffer + 23 4 5 677
- 8. Example : ComputePost-Processing Render Skybox Render The Scene Triggers a Compute Kernel Display result As a fullscreen Quad Scene Effect passes 1 2 3 4 Material Effect 1 Metal Pass Material Effect 2 Plastic pass Scene Graph Other ‘Effects’… RGBA Texture Backbuffer
- 9. Fire (Navier-Stokes equations) Simulationpasses Advect Color Advect Velocity Vorticity Confinement Emit (Gaussian ball) Fire Up-force Vel. divergence Comp. pressure Proj. Velocity Proj. Vel. edges Technique Techniques passes 1 Volume bound 1 Volume bound 2 Volume depth 2 Volume depth Smoke Ray-cast Water Ray-cast Fire Ray-cast 3 Rasterize result Rasterize 4
- 10. Inside a vkFXfile vkFX file Sampler-states Techniques Passes VertexInputState DescriptorSetLayout Framebuffer Image (texture…) Structure decl. Buffers (Uniforms, vertex, index…) DescriptorSet RenderPass GraphicsPipeline (PSO) Shader Modules (snippets of code) GLSL GLSL-Compute Later: CUDA (?) PipelineLayout PipelineRasterizationState PipelineColorBlendState PipelineDepthStencilState PipelineMultisampleState PipelineViewportState Variables ~== Vulkan Objects vkFx Features
- 11. vkFX Effect Integration Application vkFXfiles … Shader codeShader code Techs/passesTechs/passes Application vkFX files Shader codeShader code Techs/passesTechs/passes … compiled shaders Vulkan objects Vulkan objects Offline Compiler vkFX runtime Pre- compiled shaders Techs/passesStates Shader codeStates C++ vkFX Effects vkFX runtime
- 12. API Design Front-End :parser (Bison) Parses the vkFX file Does not parse the shader/compute code inside ! Back-End : the library to build the effect & Vulkan objects Used by the Front-End to build data from vkFx file Used by the application to drive the effects and Vulkan Objects Works on PC soon on Linux and Android Front-End (vkFX parser) Back-End (vkFX runtime) API Application Offline compiler
- 13. Two Ways toUse vkFX Using Techniques & Passes (== a.k.a Effects) Take advantage of higher level management of Vulkan objects Passes will initialize and validate what is needed for them to work Using vkFx descriptions as a “bag” of Vulkan Objects Initialize them Use them directly vkFx becomes is a simple way to declare Vulkan Objects
- 14.
- 15. Vulkan Objects Declaration:Graphics Pipeline Note: PSO (Pipeline-State-Object) Graphics Pipeline (combination of render-states, including shaders)
- 16. Vulkan Objects Declaration: PipelineLayout
- 17. Vulkan Objects Declaration: Shaders
- 18. Vulkan Objects Declaration: Input State; Viewport
- 19. Vulkan Objects Declaration: Render-States
- 20. Technique & PassDeclaration
- 21. Technique & Pass: Graphics-Pipeline (PSO)
- 22. Technique & Pass: Renderpass
- 23. Technique & Pass: Framebuffer target
- 24. Technique & Pass: Desc. Set
- 25. Technique & Pass: Dynamic States Note: Custom vkFx variables • Variables can change at Runtime • Will flag “dirty” any dependent object example: when resizing Windows…
- 26. Technique & Pass: Vulkan calls vkCmdBeginRenderPass(…) calls vkCmdEndRenderPass(…) (if needed) vkBeginCommandBuffer(…) calls vkBeginCommandBuffer(…) vkCmdBindPipeline(…) vkCmdSetViewport(…) vkCmdSetScissors(…) vkCmdBindDescriptorSets(…) Technique::begin() Technique::end() Pass::execute(…) Pass::execute(…) Pass::execute(…)
- 27. Technique & Pass: RenderMode
- 28. Technique & Pass: RenderMode ‘status’ contains the ID of the PSO (Graphics- Pipeline) ‘execute’ will pick the right instance from ‘status’ that matches the expected PSO
- 29. Scene-Level / Multi-LevelEffects pre/post-processing are Effects, too : Scene-Level Effect Material on a mesh can be an Effect : Primitive/Material-Level Scene-level Effects and Material Effects must be consistent How material works with “Deferred shading” ? Shadowing of the scene ? How Material takes lighting defined at Scene level ? vkFX helps to prepare the combinatorial of Material-Techniques Scene-Level techniques Material-Level shaders/PSO created for the needs of the Parent Scenes Generates instances of shaders; States (PSO) and resource update
- 30. Metal Pass PSO Override(b) Pass 2: Scene PSO (A) Combinatorial Of Effects Pass 1: Skybox in HDR Scene Effect Material Tech.1 FS 1 FS 5 VS 1 IL1 FS 2 FS 3 VS 2 DS [0] … FS 11 DS [1] IL2 Metal Pass PSO Instance (Ab) Material Tech.1 for Effect 1 / Pass 2 FS 11 DS [1] IL2 FS 5 VS 1 VS 2 DS [0]
- 31. Combinatorial Of Effects Pass2: Scene PSO (A) Pass 1: Skybox in HDR Scene Effect 1 … Metal Pass PSO Override (b) Material Tech.M2 Metal Pass PSO Override (b) Material Tech.M1 Metal Pass PSO Override (b) Material Tech.M2 Metal Pass PSO Override (b) Material Tech.M1 Scene Effect 2 Pass 2: Scene PSO (B) Metal Pass PSO Override (b) Material Tech.M1 Metal Pass PSO Override (b) Material Tech.M2 For Scene Effect 1 For Scene Effect 2
- 32. Scope where This Technique CanApply (combinatorial) Mixing 2 Levels of Techniques “VoronoiMaterial” overrides parts of the PSO Of the Scene-level PSO (“meshTriPSO”) referenced by the Scene-Pass Redefines some snippets of GLSL Code Redefines some Parameters Generates hybrid PSO from the mix
- 33. Offline Compiler How itworks and what does it do Parses vkFx Generates C++ source code generated code is Readable, clean and commented Generates Spir-V code (+GLSL Stitched code) Vulkan Objects : code for initialization / Instantiation; destruction Techniques and Passes : Initialization; execution; Stitches Snippets of Shaders Raises Compilation errors on GLSL Stitched shaders Raises Vulkan Object creation Errors Offline compiler tries to create objects with Vulkan Debug layers
- 34. How To Use C++Invocation of vkFx Techniques 1. Choose a Technique, Initialize it 2. Loop in passes and Execute Passes vkFx Contributes to Command-buffer feeding (vkCmd…) vkFx May start a render-pass or go to the next sub-pass 3. feed the command-buffer with drawcalls etc. 4. Loop to the next Pass, if needed 5. End the Technique (might end the render-pass)
- 35. How To UsevkFX: Direct Use Of Components
- 36. Near Goals /Future Work Release it as Open-Source (Github) in a month from now Check https://github.com/tlorach/vkFX (or contact me) Consolidate the Parser’s source code Vulkan objects Validation through Vulkan debug layers Finalize vkFx runtime library vkFX to expose NVIDIA extensions Add a “Simple Effect Mode” User doesn’t need to precisely define Vulkan components Compiler build missing parts using default patterns
- 37. Thank You pre-release asOpen-Source Check https://github.com/tlorach/vkFX (or contact me) Feedback : tlorach@nvidia.com
Editor's Notes
- #10 ~2500 C++ lines of code saved More code on vkFx file More flexibility outside of the C++ compiled part