Tetra3D is a pure-Go 3D game engine and rendering library built on top of Ebiten (a 2D game library). It provides a full scene graph with nodes, models, cameras, lights, materials, and animations, along with collision detection, particle systems, text rendering, and pathfinding grids. The architecture is a library with a rich set of examples demonstrating each feature. Key entry points include the tetra3d package root, Camera.RenderScene() for rendering, and gltf.LoadGLTF() for asset loading. Data flows involve loading GLTF/GLB files (with custom Blender exporter metadata), constructing a scene graph, and rendering per frame with support for lighting, shadows, and transparency. External dependencies are Ebiten for rendering/input, qmuntal/gltf for GLTF parsing, tanema/gween for tweening, and golang.org/x/image for font rendering. The codebase includes SIMD-optimized matrix math, a comprehensive vector library, and a Blender addon for exporting scenes with engine-specific properties.