Horde3D - Next-Generation Graphics Engine

Horde3D is a small open source 3D rendering engine. It is written in an effort to create a graphics engine that offers the stunning visual effects expected in next-generation games while at the same time being as lightweight and conceptually clean as possible. Horde3D has a simple and intuitive interface accessible from virtually any programming language and is particularly suitable for rendering large crowds of animated characters in next-generation quality.

Horde3D is a small open source 3D rendering engine. It is written in an effort to create a graphics engine that offers the stunning visual effects expected in next-generation games while at the same time being as lightweight and conceptually clean as possible. Horde3D has a simple and intuitive interface accessible from virtually any programming language and is particularly suitable for rendering large crowds of animated characters in next-generation quality.

 

Current Features

The following features are implemented in the current release

General Features

• Powerful graphics engine designed to meet the requirements of next-generation games
• Shader driven architecture with SM 2.0 compatible hardware as a minimum requirement
• Simple and lightweight overall design with very few dependencies, avoiding complexity where possible
• Clean object-oriented C++ code
• Simple and intuitive C-style DLL interface for easy integration with virtually any programming language
• Cross-platform compatible using OpenGL as rendering API
• Suitable for Augmented Reality (AR) and stereo applications
• Functionality for easy integration with game engines and other middleware like physics engines

 

Resource Features

• Robust resource management for avoiding unnecessary loading of data
• Garbage collection for handling resource dependencies
• Interface for loading data from files, streams or any type of archives
• Dynamic reloading of resources for more efficient development
• Loading of models and animations from optimized binary formats
• Loading of materials from a custom XML format
• Loading of shaders from a custom XML format including vertex and fragment shaders written in GLSL
• Loading of 2D and cubemap textures in jpg, png, tga, bmp, psd and HDR formats
• Loading of pipelines to quickly switch rendering techniques (e.g. from forward to deferred shading)

 

Scene Features

• Scene graph structure with hierarchical transformations and bounding volumes
• Unified scene system where world, models and skeletons are just scene graph branches and no special objects
• Loading of scene graph branches from XML files with complete orthogonality to API functions
• Optimized frustum culling on the scene graph using AABB trees
• Occlusion culling
• Level of detail support
• Possibility to attach scene nodes to joints (e.g. for character props)
• Access to vertex data for collision detection and interoperability with physics engines
• Ray collision queries and node picking

 

Animation Features

• Unified animation system working directly on scene graph
• Keyframe animation for joints and meshes
• Skeletal animation with up to 4 weights per vertex for articulated models
• Layered animation blending and mixing using masks and additive channels
• Inter-frame interpolation for smooth animations
• Access to joint data for dynamic animations and ragdoll physics
• Morph targets for facial animation and lip synchronization

 

Visual Features

• XML based customizable rendering pipeline with allocatable render targets and commands for rapid testing of different rendering techniques
• Postprocessing framework for effects like bloom, DOF or motion blur
• Support for forward rendering and different deferred shading techniques
• Support for High Dynamic Range (HDR) textures and lighting
• Support for almost all modern rendering techniques, including normal-mapped phong lighting and parallax mapping
• Support for real-time reflections and other techniques that require several cameras for rendering
• Realtime shadows based on Parallel Split Shadow Maps
• Shaders for materials and light source interaction
• Software skinning and vertex shader skinning for rendering hundreds of animated characters
• Fully integrated particle systems that can cast shadows and receive other effects like motion blur
• Overlays for rendering GUI elements and font

 

Tool Features

• Powerful Collada Converter for importing model data and animation from many widely used modelling packages
• Calculation of tangent space basis for bump mapping
• Optimization of geometry for GPU cache
  
• Powerful editor for composing scenes and developing shaders and rendering techniques

 

Hardware requirements

Horde3D requires an OpenGL 2.0 compatible graphics card with support for floating point buffers like a GeForce 6 series card or Radeon 9500.

To assure best compatibility, the engine is usually tested on different NVidia and ATI hardware cofigurations at the Multimedia Lab of the University of Augsburg.