1. Yingcai Xiao Voxel Game Engine Development

2. What do we need? What tools do we have? How can we design and implement? We will answer those questions in an agile way. Game Engine Development

3. What do we need?

4. Video Game: Interactive animation Input Device Driver Display Device Driver (GDI) Display Device Driver (GDI) Game (Software)

5. Video Game: Interactive animation Similar to all other programs: data, algorithms, input, output. Data: Game Objects Algorithms: Animation Input: Interactive Events Output: Display

6. Voxel Based Game Engine

7. Game Objects (GO) Conversions to indexed meshes:

8. Game Objects (GO) Convert a uniform grid into an indexed mesh. O(0,0,0) D(1,1,1) 2x2x2

9. Voxel based game engines: VoxelVoxel: volume element, the smallest unit in a 3D space partitioning. Strictly, it is a block in uniform grid or hexahedral network. Broadly speaking, a pyramid in a tetrahedral network can be considered as a voxel too. http://en.wikipedia.org/wiki/Voxel https://sites.google.com/site/letsmakeavoxelengin e/https://sites.google.com/site/letsmakeavoxelengin e/ http://www.vox-game.com http://www.vox-game.com/media/

10. Volume Representation Voxel based volume representation: Hexahedral / Tetrahedral Meshes Volume Deformation http://coewww.rutgers.edu/www2/vizlab/?q=node/4 8 http://coewww.rutgers.edu/www2/vizlab/?q=node/4 8 Volume Deformation code: VolDefo http://coewww.rutgers.edu/www2/vizlab/node/59VolDefo http://coewww.rutgers.edu/www2/vizlab/node/59

11. Voxel based game engines? Or not! Ray casting engines may not be voxel engines if the ray stops at the surface of game objects.Ray casting engines may not be voxel engines if the ray stops at the surface of game objects. Outcast is not really voxel based. It just uses surface-based Ray Casting, not volume based ray casting.Ray Castingvolume based ray casting. The Voxel Space engine / Comanche (series), ray casted terrain for flight simulation.Voxel Space Comanche (series)

12. Voxel based game engines? Or not! The Voxel Space engine / Comanche (series), ray casted terrain for flight simulation.Voxel Space Comanche (series) http://en.wikipedia.org/wiki/Wolfenstein_3D_engin ehttp://en.wikipedia.org/wiki/Wolfenstein_3D_engin e http://tech.slashdot.org/story/14/09/25/1534207/eu clideon-teases-photorealistic-voxel-based-game- engine (laser scanned 3D surface)http://tech.slashdot.org/story/14/09/25/1534207/eu clideon-teases-photorealistic-voxel-based-game- engine

13. Tools for future Voxel-based game engines: VTK: open source voxel-based volume rendering library. http://www.vtk.orghttp://www.vtk.org www.kitware.com http://en.wikipedia.org/wiki/Game_engine

14. Game Objects (GO) Attributes: Appearance color, normal, transparency, texture, bumpy map, normal map, …

15. Game Objects (GO) Physical Properties: rigid (fixed geometry) deformable (changeable geometry) breakable (changeable topology) intangible (no defined geometry) roughness, friction, reflection and refraction coefficients, weight, …

16. Animation Keyframe: Most commonly used. Need to provide GUI for entering the keyframes. Procedural: For advanced physical simulation. Tracking live actor: Can be modified and saved.

17. Input Devices CLI: Command Line Input Keyboard based GUI: Graphical User Interface Mouse, touch screen, … NUI: Natural User Interface Kinect, Leap Motion, …

18. Output Hardware: Video Controller Graphics Card (2D/3D) GPU (graphics processing unit, a dedicated processing unit for rendering 3D graphics)GPU GPGPU (general purpose GPU, mostly used as servers for high performance computing / HPC) Printers (2D / 3D)

19. Output Software: GDI: Graphics Device Interface OpenGL (WebGL, OpenGL-ES)OpenGL OpenCL / Vulkan for GPUVulkan ActiveX 3D