Methane Asteroids Sample

Asteroids sample demonstrates multi-threaded rendering of large number of random-generated asteroids with Methane Kit library using one of modern graphics APIs (DirectX 12, Vulkan or Metal) and platform independent implementation. Thousands of unique asteroid instances (1000-50000) are drawn with individual draw-call parameters in parallel with a random combination of:

random-generated mesh (from array of up to 1000 unique meshes),
random generated perlin-noise array texture each with 3 projections (from array of up to 50 unique textures),
random combination of coloring (from 72 color combinations).

Methane Asteroids sample was inspired by Intel Asteroids D3D12, but implemented from scratch in a cross-platform style using Methane Kit.

Platform	Graphics API	Screenshot
Windows	DirectX 12 Vulkan
Linux	Vulkan
MacOS	Vulkan Metal
iOS, tvOS	Metal

Build Instructions

Features

Default parameters of asteroids simulation are selected depending on CPU HW cores count and are displayed in right-bottom panel (switched with F3 key). Overall scene complexity can be reduced or increased by pressing [ / ] keys. Sample renders galaxy background using Methane::Graphics::SkyBox and planet using generated Methane::Graphics::SphereMesh with spherical texture coordinates. It also uses interactive Arc-Ball camera rotated with mouse LMB and light rotated with RMB with keyboard shortcuts also available (see in help by F1 key).

Rendering Optimizations

Asteroid meshes use dynamically selected LODs depending on estimated screen size. This allows to greatly reduce GPU overhead. Use L key to enable LODs coloring and ' / ; keys to increase / reduce overall mesh level of details.
Parallel rendering of asteroids array with individual draw-calls allows to be less CPU bound. Multi-threading can be switched off for comparing with single-threaded rendering by pressing P key.
Parallel updating of asteroid transformation matrices in AsteroidsArray::Update and encoding asteroid meshes rendering in MeshBuffers::DrawParallel are implemented using Taskflow library which enables effective usage of the thread-pool via parallel_for primitive.
All asteroid textures are bound to program uniform all at once as an array of textures to minimize number of program binding calls between draws. Particular texture is selected on each draw call using index parameter in constants buffer. Note that each asteroid texture is a texture 2d array itself with 3 mip-mapped textures used for triplane projection.
Inverted depth buffer (with values from 1 in foreground to 0 in background and greater-or-equal compare function) is used to minimize frame buffer overdrawing by rendering in order from foreground to background: asteroids array with planet are drawn first and sky-box afterwards.

Controls

Keyboard actions

Keyboard Action	Shortcut	Controller
APPLICATION SETTINGS
Show controls help	`F1`	Platform::AppController
Show command-line help	`F2`	Platform::AppController
Show parameters	`F3`	Platform::AppController
Switch heads-up-display mode	`F4`	UserInterface::AppController
Switch full-screen	`LCtrl` + `F`	Platform::AppController
Close application	`LCtrl`/`LCmd` + `Q`	Platform::AppController
Switch animations on/off	`LCtrl` + `P`	Graphics::AppController
GRAPHICS CONTEXT SETTINGS
Switch vertical synchronization	`LCtrl` + `V`	Graphics::AppContextController
Switch device used for rendering	`LCtrl` + `X`	Graphics::AppContextController
Add frame buffer to swap-chain	`LCtrl` + `+`	Graphics::AppContextController
Remove frame buffer from swap-chain	`LCtrl` + `-`	Graphics::AppContextController
VIEW CAMERA
Move camera left	`A`	Graphics::AppCameraController
Move camera right	`D`	Graphics::AppCameraController
Move camera forward	`W`	Graphics::AppCameraController
Move camera backward	`S`	Graphics::AppCameraController
Move camera up	`Page Up`	Graphics::AppCameraController
Move camera down	`Page Down`	Graphics::AppCameraController
Yaw camera left	`Left`	Graphics::AppCameraController
Yaw camera right	`Right`	Graphics::AppCameraController
Pitch camera up	`Up`	Graphics::AppCameraController
Pitch camera down	`Down`	Graphics::AppCameraController
Roll camera left	`<`	Graphics::AppCameraController
Roll camera right	`>`	Graphics::AppCameraController
Zoom camera in	`+`	Graphics::AppCameraController
Zoom camera out	`-`	Graphics::AppCameraController
Change camera pivot	`LAlt` + `P`	Graphics::AppCameraController
Reset camera orientation	`LAlt` + `R`	Graphics::AppCameraController
LIGHT SOURCE
Reset light orientation	`LCtrl` + `L`	Graphics::AppCameraController
ASTEROIDS SETTINGS
Switch Parallel Rendering	`P`	Samples::AsteroidsAppController
Switch Mesh LODs Coloring	`L`	Samples::AsteroidsAppController
Increase Mesh LOD Complexity	`'`	Samples::AsteroidsAppController
Decrease Mesh LOD Complexity	`;`	Samples::AsteroidsAppController
Increase Scene Complexity	`]`	Samples::AsteroidsAppController
Decrease Scene Complexity	`[`	Samples::AsteroidsAppController
Set Scene Complexity 0 .. 9	`0..9`	Samples::AsteroidsAppController

Mouse actions

Mouse action	Mouse Button	Controller
VIEW CAMERA
Rotate camera	Left Button	Graphics::AppCameraController
Zoom camera	Ver. Scroll Wheel	Graphics::AppCameraController
Move camera	Middle Button	Graphics::AppCameraController
LIGHT SOURCE
Rotate Light	Right Button	Graphics::AppCameraController

Command line

Argument	Value (Default)	Description
APPLICATION SETTINGS
`-h`, `--help`	-	Print help message and exit
`-w`, `--wnd-size`	`W H` (`0.8 0.8`)	Window size in pixels or as ratio of desktop size
`-f`, `--full-screen`	`0` / `1` (`0`)	Full-screen mode
`-a`, `--animations`	`0` / `1` (`1`)	Enable animations
`-d`, `--device`	`-1` / `0..N` (`0`)	Render at adapter index, use -1 for software adapter
`-v`, `--vsync`	`0` / `1`	Vertical synchronization
`-b`, `--frame-buffers`	`0..N` (`3`)	Frame buffers count in swap-chain
`-i`, `--hud`	`0..2` (`2`)	HUD display mode (0 - hidden, 1 - in window title, 2 - in UI)
ASTEROIDS SETTINGS
`-c`, `--complexity`	`0..9`	Asteroids simulation complexity
`-s`, `--subdiv-count`	`1..N`	Mesh subdivisions count
`-t`, `--texture-array`	`0` / `1` (`0`)	Texture array enabled
`-r`, `--parallel-render`	`0` / `1` (`1`)	Parallel rendering enabled