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🚀 Greko Engine (Windows Preview)

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@craterworldstudio craterworldstudio released this 30 Mar 11:29
· 13 commits to ReworkedEngine since this release
AR-0.0.1W
50b7283

Greko Engine is a lightweight VRM rendering tool designed for developers, artists, and hobbyists who want to load and interact with VRoid / VRM characters outside of traditional VTubing software.

This Windows release focuses on providing a clean, programmable rendering pipeline for VRM models through a native C++ OpenGL backend with Python integration.

Unlike streaming-focused avatar tools, Greko is built as a developer sandbox and experimentation platform.

✨ What This Is

  • A standalone VRM viewer + renderer
  • A developer-friendly sandbox for experimenting with VRM characters
  • A bridge between Python scripting and native C++ rendering
  • A Windows-native .pyd powered rendering runtime

❌ What This Is NOT

  • Not a VTuber app (no streaming, face tracking, webcam integration)
  • Not a full game engine (yet)
  • Not a polished production tool (early alpha build)

🚀 Features

🧍 VRM / VRoid Model Support

  • Loads .vrm files directly
  • Full skeleton support
  • Tested with 133–200 joints
  • Compatible with older VRM 1.x models
  • Morph targets / blendshapes fully working

🎭 Basic Character Animation Behaviors

  • Blinking
  • Breathing
  • Mouth sequencing (phoneme-based)
  • LookAt (bone-driven head tracking)

🎮 Interactive 3D Camera

  • WASD movement
  • EQ vertical movement
  • Mouse look
  • ESC mouse toggle

🧠 Python-Controlled Behavior System

  • Extend character logic through Python scripts
  • Runtime behavior injection
  • Modular behavior pipeline

Example systems:

  • Blinker
  • Breather
  • MouthSequencer
  • LookAt

⚡ Native C++ OpenGL Backend

  • Hardware accelerated rendering
  • Skeletal animation
  • GPU morph blending
  • Transparent / opaque render sorting
  • OpenGL 4.3 backend

🔁 Hot-Swappable Native Core

  • Replace the .pyd backend to update engine features
  • Python-side systems remain unchanged
  • Fast iteration workflow for development

📦 Included

  • launcher.py → Windows GUI launcher
  • greko_native.cp313-win_amd64.pyd → Native rendering backend
  • glfw3dll.lib → for glfw3 rendering
  • _internals → internal deps
  • Python launcher + asset selector
  • VRM model runtime loader

🛠️ How to Use

For Windows

  1. Run the launcher:

    • Download the Zip Folder and extract it in a separate standalone folder.
    • Run the launcher/launcher.exe file.
    • You can delete the engine_cache and config.json (They will regenerate when you run the program)
    • Make sure you do not forget any of the files

  2. In the UI:

    • Select the .pyd file
    • Select the folder containing .vrm files
    • Choose a model (VRM1.x models only!)
    • Click Run Engine

🎯 Use Cases

  • 🧪 Quickly testing VRM models
  • 🎮 Character system prototyping
  • 🤖 AI-driven avatar experiments
  • 🧩 Building custom avatar tools
  • 🧠 Future cognitive agent integration

🧪 Status

⚠️ Alpha Preview Release

This build is functional and stable for testing, but still under active development.

Known limitations may include:

  • early UI roughness
  • limited asset tooling
  • experimental behavior APIs
  • performance tuning still in progress

🪟 Platform

  • ✅ Windows (OpenGL 4.3+)
  • ✅ Linux supported separately
  • 🔄 Cross-platform parity achieved

🔮 Future Direction

Greko Engine is evolving toward:

  • advanced character behavior systems
  • AI-driven avatar control
  • perception and memory systems
  • modular runtime architecture
  • interactive world simulation

This release focuses on the rendering + animation foundation.

🙌 Feedback

If you try this build:

  • report bugs
  • suggest features
  • share ideas
  • test different VRM models

Your feedback directly shapes the next release.

🔥 Closing Note

There are many tools for streaming VRM avatars.

Greko exists for something different:

Rendering, controlling, and experimenting with VRM characters freely on Windows.

This is the first major Windows-native alpha build.

More updates coming soon.

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