# ogrecave/ogre architecture

> Architecture diagram of the GitHub repository ogrecave/ogre, generated by GitDiagram from its file tree, README and a sample of source files (last updated 2026-09-25). It is an AI-made overview: check details against the source.

- Interactive diagram: https://gitdiagram.com/ogrecave/ogre
- Repository: https://github.com/ogrecave/ogre

## Overview

OGRE is a modular C++ 3D rendering engine, also exposed through Python bindings. The principal workflow is an application creating a window and scene, loading resources and configuring scene content, then asking OGRE to render through a selected graphics backend to a display. Separate branches cover the README’s major capabilities: shading, compositing, animation, particles, terrain, UI, volumetrics and optional Bullet integration. The graph uses documented capabilities and sampled SceneManager/backend behavior; several subsystem links reflect the README and tree rather than inspected implementation details.

Main entry points: [`OgreMain/src/OgreSceneManager.cpp`](https://github.com/ogrecave/ogre/blob/master/OgreMain/src/OgreSceneManager.cpp) (Scene manager), [`OgreMain/include/Ogre.h`](https://github.com/ogrecave/ogre/blob/master/OgreMain/include/Ogre.h) (Engine root), [`Components/Bites/src/OgreApplicationContextBase.cpp`](https://github.com/ogrecave/ogre/blob/master/Components/Bites/src/OgreApplicationContextBase.cpp) (Application context), [`RenderSystems/GL/src/OgreGLEngineDll.cpp`](https://github.com/ogrecave/ogre/blob/master/RenderSystems/GL/src/OgreGLEngineDll.cpp) (Render system plugins)

## Diagram (Mermaid)

```mermaid
flowchart TD

subgraph group_app["Application Layer"]
  node_highpy["Python HighPy<br/>[HighPy.py]"]
  node_bites["Application context"]
  node_root["Engine root<br/>[Ogre.h]"]
  node_window["Render window<br/>[OgreRenderWindow.h]"]
end

subgraph group_scene["Scene and Resources"]
  node_scene_manager["Scene manager"]
  node_resources["Resource system"]
  node_mesh["Meshes and materials<br/>[OgreMeshManager.h]"]
  node_animation["Character animation<br/>[OgreAnimation.h]"]
  node_particles["Particle systems"]
end

subgraph group_render["Rendering Pipeline"]
  node_render_queue["Render queue<br/>[OgreRenderQueue.h]"]
  node_compositor["Compositor"]
  node_backend["Render system plugins"]
  node_gpu["Graphics API"]
end

subgraph group_features["Rendering Features"]
  node_rtshader["Runtime shader system"]
  node_terrain["Terrain and paging"]
  node_overlay["Overlay UI"]
  node_volume["Volumetric rendering"]
  node_mesh_lod["Mesh LOD"]
end

subgraph group_integrations["Integrations"]
  node_bullet["Bullet physics<br/>[OgreBullet.cpp]"]
end

node_developer(("Application developer"))
node_display(("Rendered display"))

node_developer -->|"creates app"| node_bites
node_developer -->|"calls API"| node_highpy
node_highpy -->|"wraps engine"| node_bites
node_bites -->|"initializes"| node_root
node_root -->|"creates window"| node_window
node_root -->|"creates scene"| node_scene_manager
node_scene_manager -->|"loads resources"| node_resources
node_scene_manager -->|"creates entities"| node_mesh
node_scene_manager -->|"manages animation"| node_animation
node_scene_manager -->|"manages effects"| node_particles
node_scene_manager -->|"queues visible objects"| node_render_queue
node_scene_manager -->|"uses pipeline"| node_compositor
node_render_queue -->|"submits rendering"| node_backend
node_compositor -->|"composes passes"| node_backend
node_backend -->|"issues graphics commands"| node_gpu
node_gpu -->|"renders frames"| node_display
node_scene_manager -.->|"generates shaders"| node_rtshader
node_scene_manager -.->|"renders terrain"| node_terrain
node_scene_manager -.->|"renders overlays"| node_overlay
node_scene_manager -.->|"renders volumes"| node_volume
node_mesh -.->|"generates LOD"| node_mesh_lod
node_developer -.->|"integrates physics"| node_bullet
node_bullet -.->|"provides physics objects"| node_scene_manager

click node_highpy "https://github.com/ogrecave/ogre/blob/master/Components/Python/HighPy.py"
click node_bites "https://github.com/ogrecave/ogre/blob/master/Components/Bites/src/OgreApplicationContextBase.cpp"
click node_root "https://github.com/ogrecave/ogre/blob/master/OgreMain/include/Ogre.h"
click node_window "https://github.com/ogrecave/ogre/blob/master/OgreMain/include/OgreRenderWindow.h"
click node_scene_manager "https://github.com/ogrecave/ogre/blob/master/OgreMain/src/OgreSceneManager.cpp"
click node_resources "https://github.com/ogrecave/ogre/blob/master/OgreMain/include/OgreResourceGroupManager.h"
click node_mesh "https://github.com/ogrecave/ogre/blob/master/OgreMain/include/OgreMeshManager.h"
click node_animation "https://github.com/ogrecave/ogre/blob/master/OgreMain/include/OgreAnimation.h"
click node_particles "https://github.com/ogrecave/ogre/blob/master/OgreMain/include/OgreParticleSystem.h"
click node_render_queue "https://github.com/ogrecave/ogre/blob/master/OgreMain/include/OgreRenderQueue.h"
click node_compositor "https://github.com/ogrecave/ogre/blob/master/OgreMain/include/OgreCompositorManager.h"
click node_backend "https://github.com/ogrecave/ogre/blob/master/RenderSystems/GL/src/OgreGLEngineDll.cpp"
click node_rtshader "https://github.com/ogrecave/ogre/blob/master/Components/RTShaderSystem/src/OgreShaderGenerator.cpp"
click node_terrain "https://github.com/ogrecave/ogre/blob/master/Components/Terrain/src/OgreTerrainGroup.cpp"
click node_overlay "https://github.com/ogrecave/ogre/blob/master/Components/Overlay/src/OgreOverlayManager.cpp"
click node_volume "https://github.com/ogrecave/ogre/blob/master/Components/Volume/src/OgreVolumeMeshBuilder.cpp"
click node_mesh_lod "https://github.com/ogrecave/ogre/blob/master/Components/MeshLodGenerator/src/OgreMeshLodGenerator.cpp"
click node_bullet "https://github.com/ogrecave/ogre/blob/master/Components/Bullet/src/OgreBullet.cpp"

classDef toneNeutral fill:#f8fafc,stroke:#334155,stroke-width:1.5px,color:#0f172a
classDef toneBlue fill:#dbeafe,stroke:#2563eb,stroke-width:1.5px,color:#172554
classDef toneAmber fill:#fef3c7,stroke:#d97706,stroke-width:1.5px,color:#78350f
classDef toneMint fill:#dcfce7,stroke:#16a34a,stroke-width:1.5px,color:#14532d
classDef toneRose fill:#ffe4e6,stroke:#e11d48,stroke-width:1.5px,color:#881337
classDef toneIndigo fill:#e0e7ff,stroke:#4f46e5,stroke-width:1.5px,color:#312e81
classDef toneTeal fill:#ccfbf1,stroke:#0f766e,stroke-width:1.5px,color:#134e4a
class node_highpy,node_bites,node_root,node_window toneBlue
class node_scene_manager,node_resources,node_mesh,node_animation,node_particles toneAmber
class node_render_queue,node_compositor,node_backend,node_gpu toneMint
class node_rtshader,node_terrain,node_overlay,node_volume,node_mesh_lod toneRose
class node_bullet,node_developer,node_display toneIndigo
```

## Components

### Application Layer

- [Python HighPy](https://github.com/ogrecave/ogre/blob/master/Components/Python/HighPy.py): `Components/Python/HighPy.py`
- [Application context](https://github.com/ogrecave/ogre/blob/master/Components/Bites/src/OgreApplicationContextBase.cpp): `Components/Bites/src/OgreApplicationContextBase.cpp`
- [Engine root](https://github.com/ogrecave/ogre/blob/master/OgreMain/include/Ogre.h): `OgreMain/include/Ogre.h`
- [Render window](https://github.com/ogrecave/ogre/blob/master/OgreMain/include/OgreRenderWindow.h): `OgreMain/include/OgreRenderWindow.h`

### Scene and Resources

- [Scene manager](https://github.com/ogrecave/ogre/blob/master/OgreMain/src/OgreSceneManager.cpp): `OgreMain/src/OgreSceneManager.cpp`
- [Resource system](https://github.com/ogrecave/ogre/blob/master/OgreMain/include/OgreResourceGroupManager.h): `OgreMain/include/OgreResourceGroupManager.h`
- [Meshes and materials](https://github.com/ogrecave/ogre/blob/master/OgreMain/include/OgreMeshManager.h): `OgreMain/include/OgreMeshManager.h`
- [Character animation](https://github.com/ogrecave/ogre/blob/master/OgreMain/include/OgreAnimation.h): `OgreMain/include/OgreAnimation.h`
- [Particle systems](https://github.com/ogrecave/ogre/blob/master/OgreMain/include/OgreParticleSystem.h): `OgreMain/include/OgreParticleSystem.h`

### Rendering Pipeline

- [Render queue](https://github.com/ogrecave/ogre/blob/master/OgreMain/include/OgreRenderQueue.h): `OgreMain/include/OgreRenderQueue.h`
- [Compositor](https://github.com/ogrecave/ogre/blob/master/OgreMain/include/OgreCompositorManager.h): `OgreMain/include/OgreCompositorManager.h`
- [Render system plugins](https://github.com/ogrecave/ogre/blob/master/RenderSystems/GL/src/OgreGLEngineDll.cpp): `RenderSystems/GL/src/OgreGLEngineDll.cpp`
- **Graphics API**

### Rendering Features

- [Runtime shader system](https://github.com/ogrecave/ogre/blob/master/Components/RTShaderSystem/src/OgreShaderGenerator.cpp): `Components/RTShaderSystem/src/OgreShaderGenerator.cpp`
- [Terrain and paging](https://github.com/ogrecave/ogre/blob/master/Components/Terrain/src/OgreTerrainGroup.cpp): `Components/Terrain/src/OgreTerrainGroup.cpp`
- [Overlay UI](https://github.com/ogrecave/ogre/blob/master/Components/Overlay/src/OgreOverlayManager.cpp): `Components/Overlay/src/OgreOverlayManager.cpp`
- [Volumetric rendering](https://github.com/ogrecave/ogre/blob/master/Components/Volume/src/OgreVolumeMeshBuilder.cpp): `Components/Volume/src/OgreVolumeMeshBuilder.cpp`
- [Mesh LOD](https://github.com/ogrecave/ogre/blob/master/Components/MeshLodGenerator/src/OgreMeshLodGenerator.cpp): `Components/MeshLodGenerator/src/OgreMeshLodGenerator.cpp`

### Integrations

- [Bullet physics](https://github.com/ogrecave/ogre/blob/master/Components/Bullet/src/OgreBullet.cpp): `Components/Bullet/src/OgreBullet.cpp`

### Other components

- **Application developer**
- **Rendered display**

## Connections

- Application developer → Application context: creates app
- Application developer → Python HighPy: calls API
- Python HighPy → Application context: wraps engine
- Application context → Engine root: initializes
- Engine root → Render window: creates window
- Engine root → Scene manager: creates scene
- Scene manager → Resource system: loads resources
- Scene manager → Meshes and materials: creates entities
- Scene manager → Character animation: manages animation
- Scene manager → Particle systems: manages effects
- Scene manager → Render queue: queues visible objects
- Scene manager → Compositor: uses pipeline
- Render queue → Render system plugins: submits rendering
- Compositor → Render system plugins: composes passes
- Render system plugins → Graphics API: issues graphics commands
- Graphics API → Rendered display: renders frames
- Scene manager → Runtime shader system: generates shaders
- Scene manager → Terrain and paging: renders terrain
- Scene manager → Overlay UI: renders overlays
- Scene manager → Volumetric rendering: renders volumes
- Meshes and materials → Mesh LOD: generates LOD
- Application developer → Bullet physics: integrates physics
- Bullet physics → Scene manager: provides physics objects