zakgof/korender

3D graphics engine for Kotlin Multi-Platform

korender

Kotlin Multiplatform 3D graphics rendering engine based on OpenGL / OpenGL ES.

Korender uses declarative approach that seamlessly integrates 3D viewport into Compose Multiplatform UI. Same Korender code runs on all supported platforms.

@Composable
fun App() = Korender {
  Frame {
    Camera(DefaultCamera(Vec3(0f, 5f, 30f), -1.z, 1.y))
    Pass {
      Sky(sky(FastCloud))
      Renderable(standart(FixedColor) { color = Green }, mesh = sphere(2f), transform = translate(-0.5f.y))
    }
    Pass {
      Screen(effect(Water), sky(FastCloud))
      Billboard(effect(Fire) { yscale = 10f; xscale = 2f }, position = 6.y, transparent = true)
      Gui {
        Filler()
        Text(text = "FPS ${frameInfo.avgFps}", height = 50,  color = Red, font = "/ubuntu.ttf", id = "fps")
      }
    }
  }
}

Korender is BETA - any APIs may change without notice.

Supported platforms

• Desktop (Windows/Linux) - based on LWJGL
• Android - based on OpenGL ES API

Features

• Rendering opaque and transparent objects
• Diffuse, specular and ambient lighting (directional light)
• Projection shadow maps with percentage close soft shadows
• Texturing:
  • uv mapped
  • triplanar
  • detail
• Bump mapping
• Predefined and custom meshes
• Wavefront .obj model file loading
• Billboards (sprites)
• Batching (instancing)
• Simple heightfield (terrain)
• Textured or shader sky
• On-screen basic GUI
• Custom shaders support
• Multi-pass rendering and screen-space shaders (filters)
• Simple effects
  • smoke
  • fire
  • water

Quick start

• Check out QuickStart application available at https://github.com/zakgof/korender/tree/main/quickstart

or, create an application from scratch:

• Generate a new KMP application using Kotlin Multiplatform Wizard. Select Android and Desktop platforms.
• Add Korender dependency com.github.zakgof:korender:0.2.0
• Add the above code to commonMain
• Run on desktop: .\gradlew composeApp:run

Examples showcase app

• JVM Desktop Windows: https://github.com/zakgof/korender/releases/download/0.2.0/korender-demo-0.2.0.zip
• Android APK: https://github.com/zakgof/korender/releases/download/0.2.0/korender-demo-0.2.0.apk

Examples source code

Further reading

Explore the Korender Wiki