Ilmeee Engine (In Development)

A Vulkan-based C++ game engine in active development. Built with a modular 3D pipeline supporting modern mesh formats, real-time lighting, interactive asset workflows, and companion-process IPC. The editor (GameEngineSDL) ships alongside IlmeeeHub (project launcher) and HandlerIlmeeeEngine (companion thread-safe engine process).

Building

The build is pinned to a Nix shell that brings in SDL2/3, GLFW, Vulkan, GTK3, FFmpeg, shaderc, etc.

# Enter the Nix development environment
nix-shell

# Run CMake and build within the environment
cmake -B build
make -C build -j$(nproc)

Shader compilation uses glslc which is available within the shell context:

glslc assets/shaders/vulkan/scene_mesh.vert -o assets/shaders/vulkan/scene_mesh.vert.spv

Running the editor

Two normal entry points:

# Through the Hub (recommended — wires up the project handshake):
./build/IlmeeeHub

# Standalone with an explicit project:
./build/GameEngineSDL --project /path/to/MyProject

Standalone debug fallback

When no --project is supplied, the editor boots a hardcoded debug scene so the renderer always has something to display:

./build/GameEngineSDL                # 3D: loads OBJ/PMX fallbacks
./build/GameEngineSDL --2d=true      # 2D: loads assets/testimage.png as a sprite
./build/GameEngineSDL --2d           # same as --2d=true

The 2D fallback drops a single sprite at world origin (300x300 px) and shows a dynamic editor grid + colored XY axes overlay that follow pan/zoom.

Scene & Viewport Controls

• 3D Viewport Navigation:
  • RMB drag — mouselook (FPS fly-camera)
  • WASD — fly camera forward, left, backward, right
  • Q / E — fly downward / upward
  • Shift — fast movement multiplier
• Object Interaction & Layout:
  • LMB click — Ray-Triangle Picking: Casts a ray through the viewport to select the specific 3D model and individual mesh surface under the cursor.
  • LMB drag — Move the currently selected mesh in the screen plane.
  • Drag-and-Drop Spawning: Drag .obj, .pmx, or .fbx models from the File Explorer and drop them directly onto the viewport to instantiate them at that spatial point.
  • Drag-and-Drop Texturing: Drag any texture image (.png, .jpg, etc.) onto a specific 3D mesh surface to bind it dynamically.
• Inspector Panel (Surfaces):
  • Exposes all auto-detected submesh surfaces and material slots.
  • Allows selecting individual surfaces to inspect properties or Bind/Clear Custom Textures on the fly.
• 2D Mode Navigation (no 3D mesh loaded):
  • RMB drag — pan camera
  • Wheel — zoom (0.1×–5×)
  • Toolbar Reset View resets camera

Project Structure

src/cpp/
  main.cpp                       # editor entry, CLI parsing
  ApplicationManager.cpp         # lifecycle, thread-safe network synchronization, companion startup
  Hub.cpp                        # IlmeeeHub launcher
  core_engine/
    SceneRenderer.cpp            # Vulkan mesh/viewport renderer, OBJ/PMX/FBX loaders, ray picking
    TextureManager.cpp           # Vulkan dynamic texture & descriptor pool manager
  ui/
    MainWindow.cpp               # main shell, docking, and theme controller
    HandlerChildWindow.cpp       # scene viewport, hierarchy, and surface inspector panels
    HandlerProject.cpp           # project file explorer & drag-drop asset import
assets/
  3dmodels/                      # fallback test meshes
  shaders/vulkan/                # vertex, fragment, and grid shader sources

Project File Format

Scenes are serialized to a custom high-performance binary .ilmeeescene format.

• v1.0: Stores entity counts, primitive/mesh kinds, transform fields, and path nodes.
• v1.1: Appends per-entity light properties (range, spot angle, intensity, type, color, gamma).
• v1.2 (Current): Appends per-entity camera properties (near/far plane, projection, FOV) and per-surface texture bindings (resolves relative to project root or loads absolute paths).

User preferences and recents live in the cross-platform ~/.ilmeeeengine/ location via ilmeee::UserDataRoot().

Thread-Safe Companion Architecture

The editor (GameEngineSDL) communicates with the engine runner (HandlerIlmeeeEngine) via a localized TCP loopback protocol over ports 27015 and 27016.

• All blocking modal GUI actions (such as Load Scene native file dialogs) are safely offloaded to the main thread's main loop context using GLib's g_idle_add dispatching.
• This ensures complete thread-safety across background network readers and the main rendering thread.

Status

• Vulkan renderer with offscreen target + ImGui presentation: ✅
• 2D sprite pipeline + dynamic grid overlay: ✅
• 3D Primitives (Cube, Sphere, Plane) & Camera entities: ✅
• 3D OBJ, PMX, and FBX loaders (normals, UVs, FNV-1a vertex dedup): ✅
• Surfaces & Per-surface Texture Overrides (v1.2 Scene Graph): ✅
• Ray-Triangle Picking & Viewport Drag-and-Drop: ✅
• Audio engine integration: ⏳ planned
• Android target: ⏳ planned