camera projection wip

src/app.rs

@@ -1,12 +1,19 @@
 use bevy::{
 	asset::RenderAssetUsages,
+	math::VectorSpace,
 	prelude::*,
-	render::render_resource::{Extent3d, TextureDimension, TextureFormat, TextureUsages},
+	render::{
+		render_resource::{Extent3d, TextureDimension, TextureFormat, TextureUsages},
+		view::RenderLayers,
+	},
 	window::PrimaryWindow,
 };
 use iyes_perf_ui::prelude::*;
 
-use crate::render::pipeline::{TracerPipelinePlugin, TracerRenderTextures, TracerUniforms};
+use crate::{
+	components::rt::RTCamera,
+	render::pipeline::{TracerPipelinePlugin, TracerRenderTextures, TracerUniforms},
+};
 
 pub struct Blackhole;
 
@@ -18,6 +25,7 @@ impl Plugin for Blackhole {
 		app.add_plugins(TracerPipelinePlugin);
 		app.insert_resource(TracerUniforms {
 			sky_color: LinearRgba::BLUE,
+			..default()
 		});
 
 		//Perf UI
@@ -74,5 +82,16 @@ fn setup(mut commands: Commands, mut images: ResMut<Assets<Image>>, window: Sing
 
 	commands.spawn(Camera2d);
 
+	commands.spawn((
+		// Camera3d::default(),
+		Projection::Perspective(PerspectiveProjection {
+			aspect_ratio: size.x as f32 / size.y as f32,
+			..default()
+		}),
+		RTCamera,
+		Transform::from_xyz(0.0, 0.0, 5.0).looking_at(Vec3::ZERO, Vec3::Y),
+		Name::new("RT Camera"),
+	));
+
 	commands.insert_resource(TracerRenderTextures(img0, img1));
 }

src/components/mod.rs

@@ -0,0 +1 @@
+pub mod rt;

src/components/rt.rs

@@ -0,0 +1,4 @@
+use bevy::{prelude::*, render::render_resource::encase::private::ShaderType};
+
+#[derive(Component)]
+pub struct RTCamera;

src/main.rs

@@ -4,6 +4,7 @@ use bevy::window::PresentMode;
 use bevy_inspector_egui::{bevy_egui::EguiPlugin, quick::WorldInspectorPlugin};
 
 mod app;
+pub mod components;
 mod render;
 
 pub const SHADER_ASSET_PATH: &str = "trace.wgsl";

src/render/pipeline.rs

@@ -4,6 +4,7 @@ use bevy::{
 	prelude::*,
 	render::{
 		Render, RenderApp, RenderSet,
+		camera::CameraProjection,
 		extract_resource::{ExtractResource, ExtractResourcePlugin},
 		render_asset::RenderAssets,
 		render_graph::{RenderGraph, RenderLabel},
@@ -15,11 +16,10 @@ use bevy::{
 		},
 		renderer::{RenderDevice, RenderQueue},
 		texture::GpuImage,
-		view::{ViewUniform, ViewUniforms},
 	},
 };
 
-use crate::{SHADER_ASSET_PATH, render::node::TracerNode};
+use crate::{SHADER_ASSET_PATH, components::rt::RTCamera, render::node::TracerNode};
 
 #[derive(Debug, Hash, PartialEq, Eq, Clone, RenderLabel)]
 pub struct TracerLabel;
@@ -31,6 +31,8 @@ pub struct TracerRenderTextures(pub Handle<Image>, pub Handle<Image>);
 #[derive(Resource, Clone, ExtractResource, ShaderType, Default)]
 pub struct TracerUniforms {
 	pub sky_color: LinearRgba,
+	pub world_from_clip: Mat4,
+	pub world_position: Vec3,
 }
 
 pub struct TracerPipelinePlugin;
@@ -43,6 +45,8 @@ impl Plugin for TracerPipelinePlugin {
 		));
 		app.init_resource::<TracerUniforms>()
 			.add_systems(Update, switch_textures);
+
+		app.add_systems(First, update_tracer_uniforms);
 		let render_app = app.sub_app_mut(RenderApp);
 
 		// render_app.add_systems(Startup, init_pipeline);
@@ -86,7 +90,6 @@ impl FromWorld for TracerPipeline {
 					texture_storage_2d(TextureFormat::Rgba32Float, StorageTextureAccess::ReadOnly),
 					texture_storage_2d(TextureFormat::Rgba32Float, StorageTextureAccess::WriteOnly),
 					uniform_buffer::<TracerUniforms>(false),
-					uniform_buffer::<ViewUniform>(false),
 				),
 			),
 		);
@@ -135,7 +138,6 @@ fn init_pipeline(
 				texture_storage_2d(TextureFormat::Rgba32Float, StorageTextureAccess::ReadOnly),
 				texture_storage_2d(TextureFormat::Rgba32Float, StorageTextureAccess::WriteOnly),
 				uniform_buffer::<TracerUniforms>(false),
-				uniform_buffer::<ViewUniform>(false),
 			),
 		),
 	);
@@ -170,6 +172,24 @@ fn init_pipeline(
 #[derive(Resource)]
 pub struct TracerImageBindGroups(pub [BindGroup; 2]);
 
+fn update_tracer_uniforms(
+	mut tracer_uniforms: ResMut<TracerUniforms>,
+	rt_camera: Single<(&GlobalTransform, &Projection), With<RTCamera>>,
+) {
+	let (transform, projection) = rt_camera.into_inner();
+	let view = transform.compute_matrix().inverse();
+	let clip_from_view = match projection {
+		Projection::Perspective(perspective_projection) => perspective_projection.get_clip_from_view(),
+		_ => unreachable!("This should never happen: Invalid projection type on RT Camera"),
+	};
+	let clip_from_world = clip_from_view * view;
+	let world_from_clip = clip_from_world.inverse();
+	info_once!("world_from_clip = {:?}", world_from_clip);
+
+	tracer_uniforms.world_from_clip = world_from_clip;
+	tracer_uniforms.world_position = transform.translation();
+}
+
 fn prepare_bind_groups(
 	mut commands: Commands,
 	pipeline: Res<TracerPipeline>,
@@ -178,13 +198,10 @@ fn prepare_bind_groups(
 	tracer_uniforms: Res<TracerUniforms>,
 	render_device: Res<RenderDevice>,
 	queue: Res<RenderQueue>,
-	view_uniforms: Res<ViewUniforms>,
 ) {
 	let view_a = gpu_images.get(&tracer_images.0).unwrap();
 	let view_b = gpu_images.get(&tracer_images.1).unwrap();
 
-	//Todo: Insert View Uniforms
-
 	// Uniform buffer is used here to demonstrate how to set up a uniform in a compute shader
 	// Alternatives such as storage buffers or push constants may be more suitable for your use case
 	let mut uniform_buffer = UniformBuffer::from(tracer_uniforms.into_inner());