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Skylicht Engine

Skylicht Engine, which is an evolution of the Irrlicht Project. We have upgraded more features: Sound Engine, Physics Engine, Particle Engine...

Skylicht Engine is a super lightweight Game Engine that targets mobile platforms (Android, IOS). And, it's completely free.

<img src="Documents/Media/logo-landscape.png"/>

How to build the project

PlatformBuild Status
<img src="Documents/Media/Platforms/cygwin.png" width="25" valign="middle"> Cygwin64Build status
<img src="Documents/Media/Platforms/windows.png" width="25" valign="middle"> WindowsBuild status
<img src="Documents/Media/Platforms/apple.png" width="25" valign="middle"> MacOS, IOSBuild status
<img src="Documents/Media/Platforms/ubuntu.png" width="25" valign="middle"> LinuxBuild status
<img src="Documents/Media/Platforms/emscripten.png" width="25" valign="middle"> EmscriptenBuild status
<img src="Documents/Media/Platforms/android.png" width="25" valign="middle"> AndroidBuild status

Prerequisites

Build source code

# call 'git lfs pull' after checkout
git lfs pull

C:\skylicht-engine>cd Assets
C:\skylicht-engine\Assets>python BuildAssetBundles.py
C:\skylicht-engine\Assets>cd ..

# Visual Studio 2019
C:\skylicht-engine>cmake -S . -B ./PrjVisualStudio -G "Visual Studio 16 2019" -A x64

# Visual Studio 2022
C:\skylicht-engine>cmake -S . -B ./PrjVisualStudio -G "Visual Studio 17 2022" -A x64

# Xcode
/User/Skylicht/Documents/skylicht-engine$cmake -S . -B ./PrjMac -G Xcode 

# Linux
$ skylicht-engine$ cmake -S . -B ./PrjLinux -G "Unix Makefiles"

Build data assets

Compress Texture

# Install Tinydb
# https://pypi.org/project/tinydb
C:\skylicht-engine>C:\Python37\Scripts\pip install tinydb

# Install Pillow (Image processing)
# https://pillow.readthedocs.io/en/4.1.x/index.html
C:\skylicht-engine>C:\Python37\Scripts\pip install Pillow

# Compress TGA to DDS, ETC2 texture
C:\skylicht-engine>cd Assets    
C:\skylicht-engine\Assets>python BuildTextureCompressDDS.py
C:\skylicht-engine\Assets>python BuildTextureCompressETC.py
C:\skylicht-engine\Assets>cd ..

Build Shader

# Install pcpp (C Preprocessor tool)
# https://pypi.org/project/pcpp
C:\skylicht-engine>C:\Python37\Scripts\pip install pcpp

# Build shader script
C:\skylicht-engine>cd Assets
C:\skylicht-engine\Assets>python BuildShader.py
C:\skylicht-engine\Assets>cd ..

// Assets\BuiltIn\Shader\Shadow\GLSL\LibShadow.glsl

#define HARD_SHADOW
// #define PCF_NOISE

And re-build the shaders

# Build shader script
C:\skylicht-engine>cd Assets
C:\skylicht-engine\Assets>python BuildShader.py
C:\skylicht-engine\Assets>cd ..

Add your code to Project

Add source code

C:\skylicht-engine>cmake -S . -B ./PrjVisualStudio -G "Visual Studio 17 2022" -A x64

Create application project

    C:\skylicht-engine>python Scripts\create_project.py NewApplication Samples\NewApplication

Android

Prerequisites

How to build

Step 1: Build native library

# BuildAndroidNDK.cmd
# Set your pc folder, example
set MINGW=C:\MinGW\bin
set NDK=C:\Android\android-ndk-r26d
...

Step 2: Copy native library to Gradle Project

# Make folder jniLibs on Android Project
C:\skylicht-engine>mkdir Projects\Android\app\src\main\jniLibs
C:\skylicht-engine>mkdir Projects\Android\app\src\main\jniLibs\armeabi-v7a
C:\skylicht-engine>mkdir Projects\Android\app\src\main\jniLibs\arm64-v8a

# Copy result native ndk (from step 1) to jniLibs
# Project SampleSkinnedMesh
C:\skylicht-engine>copy Bin\Android\Libs\arm64-v8a\libSampleSkinnedMesh.so Projects\Android\app\src\main\jniLibs\arm64-v8a
C:\skylicht-engine>copy Bin\Android\Libs\armeabi-v7a\libSampleSkinnedMesh.so Projects\Android\app\src\main\jniLibs\armeabi-v7a

Step 3: Copy asset resource to Gradle Project

C:\skylicht-engine\Assets>python BuildTextureCompressETC.py
C:\skylicht-engine\Assets>python BuildAssetBundles.py
C:\skylicht-engine\Assets>cd..

Android APK:

C:\skylicht-engine>SET ASSET_PATH=Projects\Android\app\src\main\assets

Android AAB: Assets will be copied to assetPack: appdata

C:\skylicht-engine>SET ASSET_PATH=Projects\Android\appdata\src\main\assets

And copy command

# Copy built-in asset
C:\skylicht-engine>copy Bin\BuiltIn.zip %ASSET_PATH%

# Copy project asset
# Project SampleSkinnedMesh
C:\skylicht-engine>copy Bin\Common.zip %ASSET_PATH%
C:\skylicht-engine>copy Bin\SampleModelsResource.zip %ASSET_PATH%

# Dont forget copy ETC texture
C:\skylicht-engine>copy Bin\SampleModelsETC.zip %ASSET_PATH%

Step 4: Build APK by Android Studio or Gradle

Open Android Studio and import project Projects\Android

<img src="Documents/Media/Samples/android/android-studio.jpg"/>

Run command build from Android Studio:

<img src="Documents/Media/Samples/android/build-apk.jpg"/>

Android development

iOS

Prerequisites

How to build

Step 1: Build compress texture ETC and Build Asset Bundles

# Grant permission executive for PVRTexTool
skylicht-engine/Tools/PVRTexTool/darwin$ chmod +x PVRTexToolCLI

# Build compress texture ETC
skylicht-engine/Assets$ python3 BuildTextureCompressETC.py

# Build asset bundles
skylicht-engine/Assets$ python3 BuildAssetBundles.py

Step 2: Generate iOS xCode Project

If you want build samples for iOS device, you should replace the bundleIdentifier in Samples/{ProjectName}/CMakeLists.txt.

elseif (BUILD_IOS)
    # replace your application name
    set(MACOSX_BUNDLE_EXECUTABLE_NAME SampleHelloWorld)
    set(APP_NAME "SampleHelloWorld")
    
    # replace your bundleIdentifier
    set(APP_BUNDLE_IDENTIFIER "com.skylicht.helloword")
    set(CODE_SIGN_IDENTITY "iPhone Developer")
    
else()

And generate iOS xCode Project by this script.

# generate project for iOS device
skylicht-engine/BuildCommand$ ./GenerateXCodeIOS.sh

# or generate for iOS simulator
skylicht-engine/BuildCommand$ ./GenerateXCodeIOSSimulator.sh

Open iOS XCode Project on folder skylicht-engine/PrjIOS/SKYLICHT_ENGINE.xcodeproj

<img src="Documents/Media/Samples/ios/iosSimulator.png"/>

Note: iOS Simulator is not yet support compressed texture and hardware skinning.

Build static or shared library

Skylicht Engine can be compiled into a standalone library to simplify integration into other projects.

Shared library

C:\skylicht-engine>cmake -S . -B ./PrjVisualStudio -G "Visual Studio 17 2022" -A x64 -DINSTALL_LIBS=ON -DBUILD_SHARED_LIBS=ON
C:\skylicht-engine>cmake --build ./PrjVisualStudio --target install --config Debug

Note: Use the parameters "-DINSTALL_LIBS=ON -DBUILD_SHARED_LIBS=ON" with cmake command

<img src="Documents/Media/dll-library.jpg"/>

Static library

C:\skylicht-engine>cmake -S . -B ./PrjVisualStudio -G "Visual Studio 17 2022" -A x64 -DINSTALL_LIBS=ON
C:\skylicht-engine>cmake --build ./PrjVisualStudio --target install --config Debug

How to integrate

And then copy the resulting InstallLibs folder to another project. See the project example: https://github.com/skylicht-lab/hello-skylicht

Roadmap

Code example

// INIT SCENE FUNCTION
// init scene/zone
CScene* scene = new CScene();
CZone* zone = scene->createZone();

// camera
CGameObject *camObj = zone->createEmptyObject();
CCamera* camera = camObj->addComponent<CCamera>();
camera->setPosition(core::vector3df(0.0f, 1.5f, 4.0f));
camera->lookAt(
   core::vector3df(0.0f, 0.0f, 0.0f),  // look at target position
   core::vector3df(0.0f, 1.0f, 0.0f)   // head up vector
);

// load model
CMeshManager* meshManager = CMeshManager::getInstance();
CEntityPrefab* meshPrefab = meshManager->loadModel("SampleModels/BlendShape/Cat.fbx", NULL, true);

// load material
CMaterialManager* materialMgr = CMaterialManager::getInstance();

// search textures folder
std::vector<std::string> textureFolders;

// use Skylicht Editor to edit .mat file
ArrayMaterial& catMaterials = materialMgr->loadMaterial("SampleModels/BlendShape/Cat.mat", true, textureFolders);

// create 3d object
CGameObject* cat = zone->createEmptyObject();
cat->setName("Cat");
cat->getTransformEuler()->setPosition(core::vector3df(0.0f, 1.0f, 0.0f));

// add render mesh component & init material
CRenderMesh* meshRenderer = cat->addComponent<CRenderMesh>();
meshRenderer->initFromPrefab(meshPrefab);
meshRenderer->initMaterial(catMaterials);

// update scene (1 frame)
scene->update();

// render scene to screen
CForwardRP* renderPipeline = new CForwardRP();

CBaseApp* app = getApplication();
u32 w = app->getWidth();
u32 h = app->getHeight();
renderPipeline->initRender(w, h);

// RENDER TO SCREEN FUNCTION
renderPipeline->render(
    NULL, // render target is screen
    camera, // the camera
    scene->getEntityManager(), // all entities in scene
    core::recti() // the viewport is fullscreen
);

Sample Projects

Samples\HelloWorld

Engine Components are used:

Samples\DrawPrimitives

This demo is to draw Cube 3D, set up, transform and use components. <img src="Documents/Media/Samples/sample_draw_cube.png"/>

Samples\Materials

This demo code, that renders Sphere 3D, loads textures (Diffuse, Normal, Specular), and binds SpecGloss shader to Material. <img src="Documents/Media/Samples/sample_material.jpg"/>

Samples\PBR

This demo code, that renders Sci-fi Helmet, loads textures (Albedo, Roughness, Metal, AO, Emissive), and binds Physically Based Rendering shader (PBR) to Material. <img src="Documents/Media/Samples/sample_pbr.jpg"/>

Samples\SampleShader

This demo code, How to binds shader to Material. <img src="Documents/Media/Samples/sample_shader.jpg"/>

Samples\LuckyDraw

Engine Components are used:

Samples\SkinnedMesh

This is example code. How to render character model with animation, models are downloaded from mixamo

Live demo: Emscripten

Blendshape live demo: Emscripten

Samples\LightmapUV

This is a demo how to use UnwrapUV tool to create Lightmap UV. Library xatlas is integrated to Skylicht Engine.

<img src="Documents/Media/Samples/lightmap-uv/lightmap-uv.png"/> <img src="Documents/Media/Samples/lightmap-uv/mesh-charts00.png" width="50%"/>

Samples\Lightmapping

This is a demo code to use lightmapper to bake indirect lighting color on lightmap texture. Project references: Lightmapper

Gazebo

<img src="Documents/Media/Samples/lightmap/lightmapping_a.jpg"/>

Result lightmap

<img src="Documents/Media/Samples/lightmap/rasterize_1.png"/>

Sponza lightmap

Sponza indirect lighting baked by Skylicht Lightmapper

<img src="Documents/Media/Samples/sponza/Sponza_indirect_01.jpg"/> <img src="Documents/Media/Samples/sponza/Sponza_indirect_02.jpg"/>

Samples\Sponza

This example is how to set up a simple lighting & lightmap. This scene uses basic diffuse bump specular shader.

<img src="Documents/Media/Samples/sponza/Sponza_01.jpg"/> <img src="Documents/Media/Samples/sponza/Sponza_02.jpg"/> <img src="Documents/Media/Samples/sponza/Sponza_03.jpg"/> <img src="Documents/Media/Samples/sponza/Sponza_04.jpg"/>

Run on Ubuntu 20.04 <img src="Documents/Media/Samples/sponza/sponza_ubuntu.jpg"/>

Live demo: (Web PC Only) Emscripten

Samples\LightmappingVertex

This is a demo to use lightmapper to set indirect lighting color on vertex color.

Engine Components are used:

Baked Global Illumination (3 bounces)

Irradiance baked on Vertex Color:

<img src="Documents/Media/Samples/tank-scene/indirect-bake-3-bounce.jpg"/>

Indirect + Direction light - No post processing (3 bounces light)

<img src="Documents/Media/Samples/tank-scene/tank-scene-3-bounce-a.jpg"/>

Samples\Collision

This is a demo to use CollisionManager to get collision point from the ray. <img src="Documents/Media/Samples/sample_collision.jpg"/>

And how to query all triangles inside a Box <img src="Documents/Media/Samples/sample_collision_box.jpg"/>

And how to use the decal projector feature <img src="Documents/Media/Samples/sample_collision_decal.jpg"/>

Live demo: (Web PC Only) Emscripten

Samples\Instancing

This is demo setup render many mesh instancing to optimize draw call and render performance.

Live demo: Emscripten

Samples\SkinnedMeshInstancing

This is a demo of drawing many characters and animations, that use GPU Instancing technique. <img src="Documents/Media/Samples/sample_skinned_instancing.jpg"/>

Samples\BoidSystem

<img src="Documents/Media/Samples/sample_bolds.jpg"/>

Samples\Particles

Skylicht Particle Component is a cleanup version of SPARK. We have optimized by GPU Billboard Instancing.

This is demo code how to create particle system and use imgui

Basic particle

<img src="Documents/Media/Samples/sample_particles.jpg"/>

Explosion demo

<img src="Documents/Media/Samples/sample_particles_explosion.jpg"/>

Magic particle

This is a demo code on how to use a simple projectile, impact, trail particle, sub emitter system. <img src="Documents/Media/Samples/sample_magic.jpg"/>

Samples\Noise2D, Noise3D

This is demo code how to use noise library shader to make vfx effect, particle turbulence.

<img src="Documents/Media/Samples/sample_noise_2d.jpg"/> <img src="Documents/Media/Samples/sample_noise_3d.jpg"/>

Contributing

Welcome if you want to contribute your code to Skylicht Engine (Ex: add feature or fix bug). Wellcome to join the group. Open an issue and submit a pull request to this repository. Please read CONTRIBUTING.md for details on our code of conduct, and the process for submitting pull requests.

Thanks

License

Skylicht Engine is licensed under MIT License

Skylicht Engine is based in part on the work of:

This means that if you've used the Skylicht Engine in your product, you must acknowledge somewhere in your documentation that you've used. It would also be nice to mention that you use the 3rd parties library... Please see the README files from 3rd parties for further information.

Thanks, Project Maintainer: Pham Hong Duc