A great source code of the voxel engine, by ken Silverman.
6 Degrees of Freedom (move anywhere, look anywhere)
Room over room built-in, no hacks necessary
Accurate intersections so voxels look like perfect cubes up close
Fast CSG operations for: boxes, spheres, ellipsoids, cylinders, sectors, and 3D convex hulls
Voxel sprites with full matrix rotation (using .KV6 output format from SLAB6)
Support for sprite bending or twisting (great for animation such as a fish swimming)
Full-screen Z-buffer for bug-free clipping of sprites
Fog of any depth or color.
Mip-mapping for both world and sprites.
Support for Mercator-projection panoramas and converter for cubic panoramas (see KUBE / KUBEGL)
Smooth collision detection and sliding
Real-time WYSIWYG editor
Real-time lighting function
Support for procedural textures (wood, etc…)
Includes all basic functions necessary for a game – including my own sample game code
Automatically detects floating objects and makes them fall
1024x1024x256 board map (this is plenty big if you take advantage of the depth)
My own optimized decompression library for PNG, JPG, GIF, TGA, BMP and ZIP files.
Everything in pure 32-bit color (with emulation for 24,16,15,8 bit color)
Uses modern compiler & OS: MS Visual C++ 6.0, Masm 6.15, Win95/98/ME/NT/2000/XP
DirectDraw, DirectSound, DirectInput fully supported
Optimized assembly code, supporting SSE (Pentium III) or 3DNow! (Athlon) instructions
Doesn’t require a 3D accelerator 🙂