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Mesh shading example (#2437)
* mesh-shader-triangle example: copied from instancing example * mesh-shader-triangle example: move shaders to separate files * mesh-shader example: rename example * mesh-shader example: implement mesh shader generating geometry * mesh-shader example: fix instance data indexing partially, still has struct alignment issues * mesh-shader example: fixed instance buffer alignment issues * remove unnecessary things Co-authored-by: marc0246 <40955683+marc0246@users.noreply.github.com> * mesh-shader example: cargo fmt * mesh-shader example: rename shaders to end in .glsl * mesh-shader example: added color out variable, docs * mesh-shader example: rename shader again * mesh-shader example: reformat shader code * mesh-shader example: cargo fmt with nightly --------- Co-authored-by: Firestar99 <4696087-firestar99@users.noreply.gitlab.com> Co-authored-by: marc0246 <40955683+marc0246@users.noreply.github.com>
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17
examples/mesh-shader/Cargo.toml
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17
examples/mesh-shader/Cargo.toml
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[package]
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name = "mesh-shader"
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version = "0.0.0"
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edition = "2021"
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publish = false
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[[bin]]
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name = "mesh-shader"
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path = "main.rs"
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test = false
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bench = false
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doc = false
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[dependencies]
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vulkano = { workspace = true, features = ["macros"] }
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vulkano-shaders = { workspace = true }
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winit = { workspace = true }
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9
examples/mesh-shader/frag.glsl
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9
examples/mesh-shader/frag.glsl
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#version 450
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layout(location = 0) in vec4 in_color;
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layout(location = 0) out vec4 f_color;
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void main() {
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f_color = in_color;
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}
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503
examples/mesh-shader/main.rs
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503
examples/mesh-shader/main.rs
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// Welcome to the mesh shader example!
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//
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// This is a simple, modified version of the `instancing.rs` example that demonstrates how to use mesh shaders to
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// generate geometry, that looks identical to the instancing example. We expect you to be familiar with both
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// instancing and compute shaders before approaching mesh shaders, due to their high complexity.
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//
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// This example is intentionally kept simple and does not follow the recommended pattern by which one should emit
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// vertices and indices. This pattern should best match what the hardware likes, and thus is unique to each vendor.
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//
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// See these presentation slides for an overview of mesh shaders and best practices:
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// https://vulkan.org/user/pages/09.events/vulkanised-2023/vulkanised_mesh_best_practices_2023.02.09-1.pdf
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// Presentation: https://www.youtube.com/watch?v=g9FoZcEQlbA
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use std::{error::Error, sync::Arc};
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use vulkano::{
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buffer::{Buffer, BufferContents, BufferCreateInfo, BufferUsage},
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command_buffer::{
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allocator::StandardCommandBufferAllocator, CommandBufferBeginInfo, CommandBufferLevel,
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CommandBufferUsage, RecordingCommandBuffer, RenderPassBeginInfo,
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},
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descriptor_set::{
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allocator::StandardDescriptorSetAllocator, DescriptorSet, WriteDescriptorSet,
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},
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device::{
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physical::PhysicalDeviceType, Device, DeviceCreateInfo, DeviceExtensions, Features,
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QueueCreateInfo, QueueFlags,
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},
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image::{view::ImageView, Image, ImageUsage},
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instance::{Instance, InstanceCreateFlags, InstanceCreateInfo},
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memory::allocator::{AllocationCreateInfo, MemoryTypeFilter, StandardMemoryAllocator},
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padded::Padded,
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pipeline::{
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graphics::{
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color_blend::{ColorBlendAttachmentState, ColorBlendState},
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multisample::MultisampleState,
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rasterization::RasterizationState,
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viewport::{Viewport, ViewportState},
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GraphicsPipelineCreateInfo,
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},
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layout::PipelineDescriptorSetLayoutCreateInfo,
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DynamicState, GraphicsPipeline, Pipeline, PipelineBindPoint, PipelineLayout,
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PipelineShaderStageCreateInfo,
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},
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render_pass::{Framebuffer, FramebufferCreateInfo, RenderPass, Subpass},
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single_pass_renderpass,
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swapchain::{
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acquire_next_image, Surface, Swapchain, SwapchainCreateInfo, SwapchainPresentInfo,
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},
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sync::{self, GpuFuture},
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DeviceSize, Validated, VulkanError, VulkanLibrary,
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};
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use winit::{
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event::{Event, WindowEvent},
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event_loop::{ControlFlow, EventLoop},
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window::WindowBuilder,
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};
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/// The vertex type that we will be used to describe the triangle's geometry.
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#[derive(BufferContents)]
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#[repr(C)]
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struct TriangleVertex {
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position: [f32; 2],
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}
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/// The vertex type that describes the unique data per instance.
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type InstanceData = mesh::Instance;
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mod mesh {
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vulkano_shaders::shader! {
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ty: "mesh",
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path: "mesh.glsl",
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vulkan_version: "1.2",
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}
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}
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mod fs {
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vulkano_shaders::shader! {
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ty: "fragment",
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path: "frag.glsl",
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}
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}
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fn main() -> Result<(), impl Error> {
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let event_loop = EventLoop::new().unwrap();
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let library = VulkanLibrary::new().unwrap();
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let required_extensions = Surface::required_extensions(&event_loop).unwrap();
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let instance = Instance::new(
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library,
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InstanceCreateInfo {
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flags: InstanceCreateFlags::ENUMERATE_PORTABILITY,
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enabled_extensions: required_extensions,
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..Default::default()
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},
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)
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.unwrap();
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let window = Arc::new(WindowBuilder::new().build(&event_loop).unwrap());
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let surface = Surface::from_window(instance.clone(), window.clone()).unwrap();
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let device_extensions = DeviceExtensions {
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khr_swapchain: true,
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ext_mesh_shader: true,
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..DeviceExtensions::empty()
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};
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let (physical_device, queue_family_index) = instance
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.enumerate_physical_devices()
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.unwrap()
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.filter(|p| p.supported_extensions().contains(&device_extensions))
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.filter_map(|p| {
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p.queue_family_properties()
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.iter()
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.enumerate()
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.position(|(i, q)| {
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q.queue_flags.intersects(QueueFlags::GRAPHICS)
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&& p.surface_support(i as u32, &surface).unwrap_or(false)
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})
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.map(|i| (p, i as u32))
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})
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.min_by_key(|(p, _)| match p.properties().device_type {
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PhysicalDeviceType::DiscreteGpu => 0,
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PhysicalDeviceType::IntegratedGpu => 1,
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PhysicalDeviceType::VirtualGpu => 2,
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PhysicalDeviceType::Cpu => 3,
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PhysicalDeviceType::Other => 4,
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_ => 5,
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})
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.unwrap();
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println!(
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"Using device: {} (type: {:?})",
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physical_device.properties().device_name,
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physical_device.properties().device_type,
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);
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let (device, mut queues) = Device::new(
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physical_device,
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DeviceCreateInfo {
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enabled_extensions: device_extensions,
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enabled_features: Features {
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mesh_shader: true,
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..Features::default()
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},
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queue_create_infos: vec![QueueCreateInfo {
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queue_family_index,
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..Default::default()
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}],
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..Default::default()
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},
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)
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.unwrap();
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let queue = queues.next().unwrap();
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let (mut swapchain, images) = {
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let surface_capabilities = device
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.physical_device()
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.surface_capabilities(&surface, Default::default())
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.unwrap();
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let image_format = device
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.physical_device()
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.surface_formats(&surface, Default::default())
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.unwrap()[0]
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.0;
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Swapchain::new(
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device.clone(),
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surface,
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SwapchainCreateInfo {
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min_image_count: surface_capabilities.min_image_count.max(2),
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image_format,
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image_extent: window.inner_size().into(),
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image_usage: ImageUsage::COLOR_ATTACHMENT,
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composite_alpha: surface_capabilities
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.supported_composite_alpha
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.into_iter()
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.next()
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.unwrap(),
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..Default::default()
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},
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)
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.unwrap()
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};
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let memory_allocator = Arc::new(StandardMemoryAllocator::new_default(device.clone()));
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let descriptor_set_allocator = Arc::new(StandardDescriptorSetAllocator::new(
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device.clone(),
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Default::default(),
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));
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// We now create a buffer that will store the shape of our triangle. This triangle is identical
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// to the one in the `triangle.rs` example.
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let vertices = [
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TriangleVertex {
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position: [-0.5, -0.25],
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},
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TriangleVertex {
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position: [0.0, 0.5],
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},
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TriangleVertex {
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position: [0.25, -0.1],
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},
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];
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let vertex_buffer = Buffer::from_iter(
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memory_allocator.clone(),
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BufferCreateInfo {
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usage: BufferUsage::STORAGE_BUFFER,
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..Default::default()
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},
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AllocationCreateInfo {
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memory_type_filter: MemoryTypeFilter::PREFER_DEVICE
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| MemoryTypeFilter::HOST_SEQUENTIAL_WRITE,
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..Default::default()
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},
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vertices,
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)
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.unwrap();
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// Now we create another buffer that will store the unique data per instance. For this example,
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// we'll have the instances form a 10x10 grid that slowly gets larger.
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let rows = 10;
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let cols = 10;
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let instances = {
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let n_instances = rows * cols;
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let mut data = Vec::new();
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for c in 0..cols {
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for r in 0..rows {
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let half_cell_w = 0.5 / cols as f32;
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let half_cell_h = 0.5 / rows as f32;
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let x = half_cell_w + (c as f32 / cols as f32) * 2.0 - 1.0;
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let y = half_cell_h + (r as f32 / rows as f32) * 2.0 - 1.0;
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let position_offset = [x, y];
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let scale = (2.0 / rows as f32) * (c * rows + r) as f32 / n_instances as f32;
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data.push(InstanceData {
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position_offset,
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scale,
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});
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}
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}
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data
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};
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let instance_buffer = Buffer::new_unsized::<mesh::InstanceBuffer>(
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memory_allocator,
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BufferCreateInfo {
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usage: BufferUsage::STORAGE_BUFFER,
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..Default::default()
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},
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AllocationCreateInfo {
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memory_type_filter: MemoryTypeFilter::PREFER_DEVICE
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| MemoryTypeFilter::HOST_SEQUENTIAL_WRITE,
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..Default::default()
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},
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instances.len() as DeviceSize,
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)
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.unwrap();
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{
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let mut guard = instance_buffer.write().unwrap();
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for (i, instance) in instances.iter().enumerate() {
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guard.instance[i] = Padded(*instance);
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}
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}
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let render_pass = single_pass_renderpass!(
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device.clone(),
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attachments: {
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color: {
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format: swapchain.image_format(),
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samples: 1,
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load_op: Clear,
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store_op: Store,
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},
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},
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pass: {
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color: [color],
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depth_stencil: {},
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},
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)
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.unwrap();
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let pipeline = {
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let mesh = mesh::load(device.clone())
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.unwrap()
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.entry_point("main")
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.unwrap();
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let fs = fs::load(device.clone())
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.unwrap()
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.entry_point("main")
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.unwrap();
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let stages = [
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PipelineShaderStageCreateInfo::new(mesh),
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PipelineShaderStageCreateInfo::new(fs),
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];
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let layout = PipelineLayout::new(
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device.clone(),
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PipelineDescriptorSetLayoutCreateInfo::from_stages(&stages)
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.into_pipeline_layout_create_info(device.clone())
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.unwrap(),
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)
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.unwrap();
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let subpass = Subpass::from(render_pass.clone(), 0).unwrap();
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GraphicsPipeline::new(
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device.clone(),
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None,
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GraphicsPipelineCreateInfo {
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stages: stages.into_iter().collect(),
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viewport_state: Some(ViewportState::default()),
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rasterization_state: Some(RasterizationState::default()),
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multisample_state: Some(MultisampleState::default()),
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color_blend_state: Some(ColorBlendState::with_attachment_states(
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subpass.num_color_attachments(),
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ColorBlendAttachmentState::default(),
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)),
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dynamic_state: [DynamicState::Viewport].into_iter().collect(),
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subpass: Some(subpass.into()),
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..GraphicsPipelineCreateInfo::layout(layout)
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},
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)
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.unwrap()
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};
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let descriptor_set = DescriptorSet::new(
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descriptor_set_allocator,
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pipeline.layout().set_layouts()[0].clone(),
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[
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WriteDescriptorSet::buffer(0, vertex_buffer.clone()),
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WriteDescriptorSet::buffer(1, instance_buffer.clone()),
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],
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[],
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)
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.unwrap();
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let mut viewport = Viewport {
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offset: [0.0, 0.0],
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extent: [0.0, 0.0],
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depth_range: 0.0..=1.0,
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};
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let mut framebuffers = window_size_dependent_setup(&images, render_pass.clone(), &mut viewport);
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let mut recreate_swapchain = false;
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let mut previous_frame_end = Some(sync::now(device.clone()).boxed());
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let command_buffer_allocator = Arc::new(StandardCommandBufferAllocator::new(
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device.clone(),
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Default::default(),
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));
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event_loop.run(move |event, elwt| {
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elwt.set_control_flow(ControlFlow::Poll);
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match event {
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Event::WindowEvent {
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event: WindowEvent::CloseRequested,
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..
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} => {
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elwt.exit();
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}
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Event::WindowEvent {
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event: WindowEvent::Resized(_),
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..
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} => {
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recreate_swapchain = true;
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}
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Event::WindowEvent {
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event: WindowEvent::RedrawRequested,
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..
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} => {
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let image_extent: [u32; 2] = window.inner_size().into();
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if image_extent.contains(&0) {
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return;
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}
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previous_frame_end.as_mut().unwrap().cleanup_finished();
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if recreate_swapchain {
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let (new_swapchain, new_images) = swapchain
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.recreate(SwapchainCreateInfo {
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image_extent,
|
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..swapchain.create_info()
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})
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.expect("failed to recreate swapchain");
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swapchain = new_swapchain;
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framebuffers = window_size_dependent_setup(
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&new_images,
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render_pass.clone(),
|
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&mut viewport,
|
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);
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recreate_swapchain = false;
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}
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let (image_index, suboptimal, acquire_future) =
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match acquire_next_image(swapchain.clone(), None).map_err(Validated::unwrap) {
|
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Ok(r) => r,
|
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Err(VulkanError::OutOfDate) => {
|
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recreate_swapchain = true;
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return;
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}
|
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Err(e) => panic!("failed to acquire next image: {e}"),
|
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};
|
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|
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if suboptimal {
|
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recreate_swapchain = true;
|
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}
|
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|
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let mut builder = RecordingCommandBuffer::new(
|
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command_buffer_allocator.clone(),
|
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queue.queue_family_index(),
|
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CommandBufferLevel::Primary,
|
||||
CommandBufferBeginInfo {
|
||||
usage: CommandBufferUsage::OneTimeSubmit,
|
||||
..Default::default()
|
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},
|
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)
|
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.unwrap();
|
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|
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builder
|
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.begin_render_pass(
|
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RenderPassBeginInfo {
|
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clear_values: vec![Some([0.0, 0.0, 1.0, 1.0].into())],
|
||||
..RenderPassBeginInfo::framebuffer(
|
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framebuffers[image_index as usize].clone(),
|
||||
)
|
||||
},
|
||||
Default::default(),
|
||||
)
|
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.unwrap()
|
||||
.set_viewport(0, [viewport.clone()].into_iter().collect())
|
||||
.unwrap()
|
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.bind_pipeline_graphics(pipeline.clone())
|
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.unwrap()
|
||||
// Instead of binding vertex attributes, bind buffers as descriptor sets
|
||||
.bind_descriptor_sets(
|
||||
PipelineBindPoint::Graphics,
|
||||
pipeline.layout().clone(),
|
||||
0,
|
||||
descriptor_set.clone(),
|
||||
)
|
||||
.unwrap();
|
||||
|
||||
unsafe {
|
||||
builder.draw_mesh_tasks([cols, rows, 1]).unwrap();
|
||||
}
|
||||
|
||||
builder.end_render_pass(Default::default()).unwrap();
|
||||
|
||||
let command_buffer = builder.end().unwrap();
|
||||
let future = previous_frame_end
|
||||
.take()
|
||||
.unwrap()
|
||||
.join(acquire_future)
|
||||
.then_execute(queue.clone(), command_buffer)
|
||||
.unwrap()
|
||||
.then_swapchain_present(
|
||||
queue.clone(),
|
||||
SwapchainPresentInfo::swapchain_image_index(swapchain.clone(), image_index),
|
||||
)
|
||||
.then_signal_fence_and_flush();
|
||||
|
||||
match future.map_err(Validated::unwrap) {
|
||||
Ok(future) => {
|
||||
previous_frame_end = Some(future.boxed());
|
||||
}
|
||||
Err(VulkanError::OutOfDate) => {
|
||||
recreate_swapchain = true;
|
||||
previous_frame_end = Some(sync::now(device.clone()).boxed());
|
||||
}
|
||||
Err(e) => {
|
||||
println!("failed to flush future: {e}");
|
||||
previous_frame_end = Some(sync::now(device.clone()).boxed());
|
||||
}
|
||||
}
|
||||
}
|
||||
Event::AboutToWait => window.request_redraw(),
|
||||
_ => (),
|
||||
}
|
||||
})
|
||||
}
|
||||
|
||||
/// This function is called once during initialization, then again whenever the window is resized.
|
||||
fn window_size_dependent_setup(
|
||||
images: &[Arc<Image>],
|
||||
render_pass: Arc<RenderPass>,
|
||||
viewport: &mut Viewport,
|
||||
) -> Vec<Arc<Framebuffer>> {
|
||||
let extent = images[0].extent();
|
||||
viewport.extent = [extent[0] as f32, extent[1] as f32];
|
||||
|
||||
images
|
||||
.iter()
|
||||
.map(|image| {
|
||||
let view = ImageView::new_default(image.clone()).unwrap();
|
||||
Framebuffer::new(
|
||||
render_pass.clone(),
|
||||
FramebufferCreateInfo {
|
||||
attachments: vec![view],
|
||||
..Default::default()
|
||||
},
|
||||
)
|
||||
.unwrap()
|
||||
})
|
||||
.collect::<Vec<_>>()
|
||||
}
|
||||
97
examples/mesh-shader/mesh.glsl
Normal file
97
examples/mesh-shader/mesh.glsl
Normal file
@ -0,0 +1,97 @@
|
||||
#version 450
|
||||
#extension GL_EXT_mesh_shader : require
|
||||
|
||||
// In mesh shaders you have to load all data manually from storage buffers, which are declared just like uniform
|
||||
// buffers, but using the `buffer` keyword. You may not use:
|
||||
// * `in`: Unlike vertex shaders, Mesh shaders do not have an input assembly (IA) stage that pulls data from buffers
|
||||
// and forwards them to the vertex shaders as `in` inputs.
|
||||
// * `uniform`: Uniform buffers have to be of constant size, but as our buffers may have a varying amount of data,
|
||||
// they have to be storage buffers instead.
|
||||
//
|
||||
// The triangle vertex positions.
|
||||
layout(set = 0, binding = 0) buffer VertexBuffer {
|
||||
vec2 position[];
|
||||
} buffer_vertex;
|
||||
|
||||
// The per-instance data.
|
||||
struct Instance {
|
||||
vec2 position_offset;
|
||||
float scale;
|
||||
};
|
||||
|
||||
layout(set = 0, binding = 1) buffer InstanceBuffer {
|
||||
Instance instance[];
|
||||
} buffer_instance;
|
||||
|
||||
// This declaration specifies the workgroup size of the mesh shader, similarly to compute shaders
|
||||
layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
|
||||
// This declares the type of primitive you want to emit, typically triangles, as well as maximum amount of vertices
|
||||
// and primitives you may emit. Primitives may only be in lists, aka. triangle_strip or triangle_fan are not allowed.
|
||||
layout(triangles, max_vertices = 3, max_primitives = 1) out;
|
||||
|
||||
// As mesh shaders may emit multiple vertices, all outputs have to be an array. See below, when vertices are emitted.
|
||||
layout(location = 0) out vec4 out_color[];
|
||||
|
||||
const uint rows = 10;
|
||||
const uint cols = 10;
|
||||
const uint n_instances = rows * cols;
|
||||
|
||||
void main() {
|
||||
vec2 position_offset;
|
||||
float scale;
|
||||
vec4 color;
|
||||
|
||||
// There are two main use-cases for mesh shaders, switch in between them here.
|
||||
// They should both draw the same triangles, but with different colors.
|
||||
const bool LOAD_FROM_INSTANCE_BUFFER = false;
|
||||
|
||||
if (LOAD_FROM_INSTANCE_BUFFER) {
|
||||
// Use-case 1: load instance data from buffers, similarly to doing an instanced draw
|
||||
// color triangles red
|
||||
color = vec4(1.0, 0.0, 0.0, 1.0);
|
||||
|
||||
Instance instance = buffer_instance.instance[gl_GlobalInvocationID.y * rows + gl_GlobalInvocationID.x];
|
||||
position_offset = instance.position_offset;
|
||||
scale = instance.scale;
|
||||
|
||||
} else {
|
||||
// Use-case 2: generate the geometry dynamically in the mesh shader
|
||||
// color triangles green
|
||||
color = vec4(0.0, 1.0, 0.0, 1.0);
|
||||
|
||||
uint c = gl_GlobalInvocationID.x;
|
||||
uint r = gl_GlobalInvocationID.y;
|
||||
|
||||
// the same algo for generating the triangle data as in the instanced example
|
||||
float half_cell_w = 0.5 / float(cols);
|
||||
float half_cell_h = 0.5 / float(rows);
|
||||
float x = half_cell_w + (c / float(cols)) * 2.0 - 1.0;
|
||||
float y = half_cell_h + (r / float(rows)) * 2.0 - 1.0;
|
||||
position_offset = vec2(x, y);
|
||||
scale = (2.0 / float(rows)) * (c * float(rows) + r) / n_instances;
|
||||
}
|
||||
|
||||
// Dynamically set the amount of vertices and triangles that you would like to emit, must be lower than what was
|
||||
// declared above. From the `OpSetMeshOutputsEXT` spec:
|
||||
// The arguments are taken from the first invocation in each workgroup. Behavior is undefined if any invocation
|
||||
// executes this instruction more than once or under non-uniform control flow. Behavior is undefined if there is
|
||||
// any control flow path to an output write that is not preceded by this instruction.
|
||||
SetMeshOutputsEXT(
|
||||
3, // vertices
|
||||
1// triangles = indices / 3
|
||||
);
|
||||
|
||||
// emit vertex data
|
||||
for (uint i = 0; i < 3; i++) {
|
||||
// As we may emit multiple vertices, all outputs are arrays. You index into them using a unique vertex index
|
||||
// within your work group. In this example the work group has the size (1, 1, 1), so each invocation can
|
||||
// simply use the indices [0-2]. With larger work groups you will have to use the `gl_LocalInvocationID` to
|
||||
// compute indices and make sure they are unique, so results don't get overridden by other invocations.
|
||||
out_color[i] = color;
|
||||
// just like setting gl_Position in the vertex shader
|
||||
gl_MeshVerticesEXT[i].gl_Position = vec4(buffer_vertex.position[i] * scale + position_offset, 0.0, 1.0);
|
||||
}
|
||||
|
||||
// emit triangle indices
|
||||
gl_PrimitiveTriangleIndicesEXT[0] = uvec3(0, 1, 2);
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user